The global demand for in vitro respiratory airway models has surged due to the coronavirus disease 2019(COVID-19)pandemic.Current state-of-the-art models use polymer membranes to separate epithelial cells from other c...The global demand for in vitro respiratory airway models has surged due to the coronavirus disease 2019(COVID-19)pandemic.Current state-of-the-art models use polymer membranes to separate epithelial cells from other cell types,creating a nonphysiological barrier.In this study,we applied three-dimensional(3D)printing and bioprinting to develop an in vitro model where endothelial and epithelial cells were in direct contact,mimicking their natural arrangement.This proof-ofconcept model includes a culture chamber,with an endothelial bioink printed and perfused through an epithelial channel.In silico simulations of the air velocity within the channel revealed shear stress values ranging from 0.13 to 0.39 Pa,aligning with the desired in vivo shear stress observed in the bronchi regions(0.1–0.4 Pa).Biomechanical movements during resting breathing were mimicked by incorporating a textile mesh positioned away from the cell–cell interface.The epithelial channel demonstrated a capacity for compression and expansion of up to−14.7%and+6.4%,respectively.Microscopic images showed that the epithelial cells formed a uniform monolayer within the lumen of the channel close to the bioprinted endothelial cells.Our novel model offers a valuable tool for future research into respiratory diseases and potential treatments under conditions closely mimicking those in the lung.展开更多
The high metabolic demands of the brain require an efficient vascular system to be coupled with neural activity to supply adequate nutrients and oxygen.This supply is coordinated by the action of neurons,glial and vas...The high metabolic demands of the brain require an efficient vascular system to be coupled with neural activity to supply adequate nutrients and oxygen.This supply is coordinated by the action of neurons,glial and vascular cells,known collectively as the neurovascular unit,which temporally and spatially regulate local cerebral blood flow through a process known as neurovascular coupling.In many neurodegenerative diseases,changes in functions of the neurovascular unit not only impair neurovascular coupling but also permeability of the blood-brain barrier,cerebral blood flow and clearance of waste from the brain.In order to study disease mechanisms,we need improved physiologicallyrelevant human models of the neurovascular unit.Advances towards modeling the cellular complexity of the neurovascular unit in vitro have been made using stem-cell derived organoids and more recently,vascularized organoids,enabling intricate studies of non-cell autonomous processes.Engineering and design innovations in microfluidic devices and tissue engineering are progressing our ability to interrogate the cerebrovasculature.These advanced models are being used to gain a better understanding of neurodegenerative disease processes and potential therapeutics.Continued innovation is required to build more physiologically-relevant models of the neurovascular unit encompassing both the cellular complexity and designed features to interrogate neurovascular unit functionality.展开更多
Neural stem cell has a potential to differentiate into neurons, astrocytes and oligodendrocytes. It provides an in vitro model to screen herbal medicines on the cellular differentiation and development level. In this ...Neural stem cell has a potential to differentiate into neurons, astrocytes and oligodendrocytes. It provides an in vitro model to screen herbal medicines on the cellular differentiation and development level. In this work, active component from gypenosides and soyasaponins was prepared to investigate their effects on the differentiation of neural stem cells.. Both gypenosides and soyasaponins promote the differentiation of neural stem cells. This method provides speed and practicality for screening effective herbal medicine. It is well suited for studying the mechanism of cell differentiation and development.展开更多
AIM:To globally compare the gene expression profiles during the capillary morphogenesis of human microvascular endothelial cells (HMVECs) in an in vitro angiogeness system with affymetrix oligonucleotide array. METHOD...AIM:To globally compare the gene expression profiles during the capillary morphogenesis of human microvascular endothelial cells (HMVECs) in an in vitro angiogeness system with affymetrix oligonucleotide array. METHODS: A microcarrier-based in vitro angiogenesis system was developed, in which ECs migrated into the matrix, proliferated, and formed capillary sprouts. The sprouts elongated, branched and formed networks. The total RNA samples from the HMVECs at the selected time points (0.5, 24, and 72 h) during the capillary morphogenesis were used for microarray analyses, and the data were processed with the softwares provided by the manufacturers. The expression patterns of some genes were validated and confirmed by semi-quantitative RT-PCR. The regulated genes were grouped based on their molecular functions and expression patterns, and among them the expression of chemokines and chemokine receptors was specially examined and their functional implications were analyzed. RESULTS: A total of 1 961 genes were up- or downreg-ulated two-folds or above, and among them, 468 genes were up- or down-regulated three-folds or above. The regulated genes could be grouped into categories based on their molecular functions, and were also clustered into six groups based on their patterns of expression. As for chemokines and chemokine receptors, CXCL1/GRO-α, CXCL2/GRO-β, CXCL5/ENA-78, CXCL6/GCP2, IL-8/CXCL8, CXCL12/SDF-1, CXCL9/Mig, CXC11/ITAC, OOCL1/fractalkine, CCL2/MCP-1, CCL3, CCL5/RANTES, CCL7, CCL15, CCL21, CCL23, CCL28, and CCR1, CCR9, CXCR4 were identified. Moreover, these genes demonstrated different changing patterns during the capillary morphogenesis, which implied that they might have different roles in the sequential process. Among the chemokines identified, CCL2/MCP-1, CCL5/RANTES and CX3CL1 were specially up-regulated at the 24-h time point when the sprouting characterized the morphological change. It was thus suggested that they might exert crucial roles at the early stage of angiogenesis. CONCLUSION: The present study demonstrates a global profile of gene expression during endothelial capillary morphogenesis, and the results provide us much information about the molecular mechanisms of angiogenesis, with which further evaluation of individual genes can be conducted.展开更多
BACKGROUND： Neuronal loss, synapse mutilation, and increasing malnourished axons are pathologically related to Alzheimer＇s disease. Microtubule-associated protein 2 （MAP2） is of importance for neuronal, axonal, an...BACKGROUND： Neuronal loss, synapse mutilation, and increasing malnourished axons are pathologically related to Alzheimer＇s disease. Microtubule-associated protein 2 （MAP2） is of importance for neuronal, axonal, and dendritic generation, extension, and stabilization, as well as for the regulation of synaptic plasticity. OBJECTIVE： To investigate the antagonistic effects of natural-cerebrolysin-containing serum on beta amyloid protein 1-40 （Aβ1-40）-induced neurotoxicity from the standpoints of cell proliferation, synaptogenesis, and cytoskeleton formation （MAP2 expression）. DESIGN, TIME AND SETTING： A paralleled, controlled, neural cell, and molecular biology experiment was performed at the Institute of Integrated Chinese and Western Medicine, Shenzhen Hospital, Southern Medical University between February 2006 and April 2008. MATERIALS： PC12 cells, derived from the rat central nervous system, were purchased from Shanghai Institute of Cell Biology, Chinese Academy of Sciences, China. A β1-40 was provided by Sigma, USA. Natural-cerebrolysin was provided by Shenzhen Institute of Integrated Chinese and Western Medicine, China. The natural-cerebrolysin was predominantly composed of Renshen （Radix Ginseng）, Tianma （Rhizoma Gastrodiae）, and Yixingye （Ginkgo Leaf） in a proportion of 1：2：2. Following conventional water extraction technology, an extract （1：20） was prepared. Each gram of extract equaled 20 grams of crude drug. In a total of 12 adult male New Zealand rabbits, six underwent intragastric administration of natural-cerebrolysin extract for 1 month to prepare natural-cerebrolysin-containing serum, and the remaining six rabbits received intragastric administration of physiological saline to prepare normal blank serum. METHODS： An AIzheimer＇s disease in vitro model was induced in PC12 cells using Aβ1-40. The cells were incubated with varying doses of natural-cerebrolysin-containing serum （2.5%, 5%, and 10%）. Normal blank serum-treated PC12 cells served as a blank control group. MAIN OUTCOME MEASURES： Through the use of inverted phase contrast microscope, cell morphology and neurite growth were observed, neurite length was measured, and the percentage of neurite-positive cells was calculated. Cell proliferation rate was determined by MTT assay, and MAP 2 expression was detected by fluorescent immunocytochemistry. RESULTS： Following Aβ1-40 treatments, some PC12 cells were apoptotic/dying, and only a few short neurites were observed. Following interventions with natural-cerebrolysin-containing serum, the PC12 cells proliferated, there was an increased number of neurites, and neurite length was enhanced. After middle- and high-dose natural-cerebrolysin treatments, the percentage of neurite-positive cells, as well as the average length of neurites, was significantly greater than the normal blank serum-treated PC12 cells （P 〈 0.05 or P 〈 0.01）. Compared with the blank control group, MAP2 expression in the Aβ1-40-treated PC12 cells was significantly inhibited, and the cell proliferation rate was significantly decreased （P 〈 0.01）. Following incubations with natural-cerebrolysin-containing serum, MAP2 expression and cell proliferation rate in the PC12 cells were significantly increased in a dose-dependent manner, compared with treatments with blank control serum （P 〈 0.05 or P 〈 0.01 ）. CONCLUSION： Natural-cerebrolysin exhibited antagonistic effects on neurotoxicity in Aβ1-40 induced Alzheimer＇s disease in vitro models. These effects were likely related to cell proliferation and the upregulation of intracellular MAP2 expression.展开更多
There is an urgent and tremendous need for human dis- ease models in drug development in order to improve pre- clinical predictability. In the case of brain disorders drugs have to cross the blood-brain barrier （BBB...There is an urgent and tremendous need for human dis- ease models in drug development in order to improve pre- clinical predictability. In the case of brain disorders drugs have to cross the blood-brain barrier （BBB） to enter the central nervous system （CNS）. It was estimated that more than 95% of the drugs cannot cross the BBB.展开更多
The aim of this work was to develop an in vitro model to study mechanical compression effects on cartilage. A pressure-controlled compression device was used in this study. Cartilage explants obtained from human knee ...The aim of this work was to develop an in vitro model to study mechanical compression effects on cartilage. A pressure-controlled compression device was used in this study. Cartilage explants obtained from human knee were compressed at 1MPa/1Hz for 7 hours (30 min ON, 30 min OFF) under normoxia (5% CO2, 21% O2) or hypoxia (5% CO2, 5% O2). Cell viability was analyzed while nitric oxide (NO) and glycosaminoglycans (GAG) release was assayed in culture media. Mechanical stimulation increased NO production and GAG release by human cartilage explants under normoxia and hypoxia culture. In normoxia and hypoxia conditions, mechanical stimulation alters human OA cartilage metabolism. There is also, an increase in matrix degradation after compression, as shown by levels of GAG found in culture media. This study put in evidence the importance of mechanical compression in the progression of the osteoarthritis and present and in vitro model for mechanobiological and pharmacological studies.展开更多
Background:Risk factors for the etiology of post-weaning diarrhea,a major problem in swine industry associated with enormous economic losses,remain to be fully elucidated.In concordance with the ethical concerns raise...Background:Risk factors for the etiology of post-weaning diarrhea,a major problem in swine industry associated with enormous economic losses,remain to be fully elucidated.In concordance with the ethical concerns raised by animal experiments,we developed a new in vitro model of the weaning piglet colon(MPigut-IVM)including a mucin bead compartment to reproduce the mucus surface from the gut to which gut microbes can adhere.Results:Our results indicated that the MPigut-IVM is able to establish a representative piglet archaeal and bacterial colon microbiota in terms of taxonomic composition and function.The MPigut-IVM was consequently used to investigate the potential effects of feed deprivation,a common consequence of weaning in piglets,on the microbiota.The lack of nutrients in the MPigut-IVM led to an increased abundance of Prevotellaceae and Escherichia-Shigella and a decrease in Bacteroidiaceae and confirms previous in vivo findings.On top of a strong increase in redox potential,the feed deprivation stress induced modifications of microbial metabolite production such as a decrease in acetate and an increase in proportional valerate,isovalerate and isobutyrate production.Conclusions:The MPigut-IVM is able to simulate luminal and mucosal piglet microbiota and represent an innovative tool for comparative studies to investigate the impact of weaning stressors on piglet microbiota.Besides,weaning-associated feed deprivation in piglets provokes disruptions of MPigut-IVM microbiota composition and functionality and could be implicated in the onset of post-weaning dysbiosis in piglets.展开更多
Objective To comparatively study the toxicity of four metal-containing nanoparticles(MNPs) and their chemical counterparts to the air-blood barrier(ABB) permeability using an in vitro model.Methods ABB model, which wa...Objective To comparatively study the toxicity of four metal-containing nanoparticles(MNPs) and their chemical counterparts to the air-blood barrier(ABB) permeability using an in vitro model.Methods ABB model, which was developed via the co-culturing of A549 and pulmonary capillary endothelium, was exposed to spherical CuO-NPs(divided into CuO-40, CuO-80, and CuO-100 based on particle size), nano-Al2O3(sheet and short-rod-shaped), nano-ZnO, nano-Pb S, CuSO4, Al2(SO4)3, Zn(CH3COO)2, and Pb(NO3)2 for 60 min.Every 10 min following exposure, the cumulative cleared volume(ΔTCL) of Lucifer yellow by the model was calculated.A clearance curve was established using linear regression analysis of ΔTCL versus time.Permeability coefficient(P) was calculated based on the slope of the curve to represent the degree of change in the ABB permeability.Results The results found the increased P values of CuO-40, CuO-80, sheet, and short-rod-shaped nano-Al2O3, Al2(SO4)3, and Pb(NO3)2.Among them, small CuO-40 and CuO-80 were stronger than CuO-100 and CuSO4;no difference was observed between Al2(SO4)3 and sheet and short-rod-shaped nano-Al2O3;and nano-Pb S was slightly weaker than Pb(NO3)2.So clearly the MNPs possess diverse toxicity.Conclusion ABB permeability abnormality means pulmonary toxicity potential.More studies are warranted to understand MNPs toxicity and ultimately control the health hazards.展开更多
Direct intercellular communication mediated by gap junctions constitutes a major regulatory platform in the control of hepatic homeostasis.Hepatocellular gap junctions are composed of two hemichannels of adjacent cell...Direct intercellular communication mediated by gap junctions constitutes a major regulatory platform in the control of hepatic homeostasis.Hepatocellular gap junctions are composed of two hemichannels of adjacent cells which are built up by connexin proteins,in casu Cx32.Mathieu Vinken,Pofessor at the Department of Toxicology of the Free University BrusselsBelgium,was one of the first investigators to demonstrate that hepatic connexin expression is controlled by epigenetic mechanisms.In particular,he found that inhibitors of histone deacetylase enzymes enhance Cx32 production and gap junction activity in cultures of primary hepatocytes,a finding that is of importance for liver-based in vitro modelling.Professor Dr.Mathieu Vinken's recent work is focussed on the elucidation of the role of connexin proteins and their channels in the hepatocyte life cycle.Specific attention is paid to apoptosis in this context,whereby it has been found that Cx32 hemichannels control the termination of induced cell death in cultures of primary hepatocytes. Overall,Professor Dr.Mathieu Vinken's research can be considered as an important contribution to the field of hepatic connexin physiology.展开更多
Chronic kidney diseases affect a significant portion of the global population and their prevalence is expected to increase in the coming years.Advanced in vitro models are crucial for understanding disease onset and f...Chronic kidney diseases affect a significant portion of the global population and their prevalence is expected to increase in the coming years.Advanced in vitro models are crucial for understanding disease onset and for improving drug testing.Emerging strategies have enhanced the accuracy of these models by incorporating 3D culture and perfusion systems.Notably,efforts have focused on modeling the nephron,particularly endothelialized and epithelialized tubular structures,with perfusion to simulate toxin exchange for nephrotoxicity testing.New approaches combining biomaterials with patient-derived kidney epithelial cells show promise for high-throughput personalized drug screening.However,these methods often rely on decellularized extracellular matrix materials,such as Matrigel®and collagen,which suffer from batch-to-batch variability.To address reproducibility issues,we used norbornene-functionalized alginate to produce peptide-functionalized thiol-ene crosslinked hydrogels.By varying the composition of crosslinkers and peptide functionalization,we tuned the cell interaction with the hydrogels.The rapid reaction kinetics enabled the bioprinting of cell-laden tubular structures using microfluidic bioprinting,without the need for ionic crosslinking,by adapting the printer with UV irradiation at the nozzle.The bioprinted fibers successfully formed monolayers,indicating their potential for creating advanced kidney in vitro models.Thiol-ene crosslinked hydrogels proved to be highly tunable and adaptable to microfluidic bioprinting,demonstrating significant promise for further application to create kidney in vitro models.展开更多
Background We investigated differences in intracranial embolus distribution through communicating arteries in relation to supra-aortic vessel(SAV)patency.Methods For this experimental analysis,we created a silicone mo...Background We investigated differences in intracranial embolus distribution through communicating arteries in relation to supra-aortic vessel(SAV)patency.Methods For this experimental analysis,we created a silicone model of the extracranial and intracranial circulations using a blood-mimicking fluid under physiological pulsatile flow.We examined the sequence of embolus lodgment on injecting 104 frangible clot analogues(406 emboli)through the right internal carotid artery(CA)as SAV patency changed:(a)all SAV patent(baseline),(b)emboli from a CA occlusion,(c)emboli contralateral to a CA occlusion and(d)occlusion of the posterior circulation.The statistical analysis included a descriptive analysis of thrombi location after occlusion(absolute and relative frequencies).Sequences of occlusions were displayed in Sankey flow charts for the four SAV conditions.Associations between SAV conditions and occlusion location were tested by Fisher’s exact test.Two-sided p values were compared with a significance level of 0.05.Results The total number of emboli was 406(median fragments/clot:4(IQR:3-5)).Embolus lodgment was dependent on SAV patency(p<0.0001).In all scenarios,embolism lodging in the anterior cerebral artery(ACA)occurred after a previous middle cerebral artery(MCA)embolism(MCA first lodge:96%,100/104).The rate of ipsilateral ACA embolism was 28.9%(28/97)at baseline,decreasing significantly when emboli originated from an occluded CA(16%,14/88).There were more bihemispheric embolisations in cases of contralateral CA occlusion(37%,45/122),with bilateral ACA embolisms preceding contralateral MCA embolism in 56%of cases(14/25 opposite MCA and ACA embolism).Conclusions All emboli in the ACA occurred after a previous ipsilateral MCA embolism.Bihemispheric embolisms were rare,except when there was a coexisting occlusion in either CA,particularly in cases of a contralateral CA occlusion.展开更多
The liver hosts a variety of immune cells while creating a tolerogenic environment under homeostatic conditions.However,most chronic liver diseases shift toward inflammation over time.Understanding and intercepting th...The liver hosts a variety of immune cells while creating a tolerogenic environment under homeostatic conditions.However,most chronic liver diseases shift toward inflammation over time.Understanding and intercepting the crosstalk between various immune cells and liver tissue is crucial,as it is often the rate-limiting factor in preclinical drug development.Owing to significant interspecies differences in liver immunology,human models,such as classical cocultures or organogenesis-inspired liver organoids with immune compartments,are becoming essential for advancing the field.Therefore,this review evaluates human-specific models of hepatic-immune crosstalk and assesses a range of models from basic 2D cultures to microphysiological systems(MPSs)and advanced multitissue organoids.It serves as a guide for experimentalists to identify suitable approaches.For example,traditional cocultures offer robustness,reductionist approaches,and modularity but have limited spatial fidelity and cell heterogeneity.In contrast,multitissue organoids inspired by mammalian ontogeny are created from pluripotent stem cells and integrate multiple tissue niche-constituting cells,which include Kupffer-like cells.In conclusion,this review discusses progress in human liver immunology modeling and highlights limitations and numerous untapped opportunities.These include the potential to model in vitro autoimmunity and more complex myeloid inflammatory responses,incorporating contributions from embryonic tissue and bone marrow.Additionally,future in vitro models may include hard-to-culture populations such as neutrophils.展开更多
Objective:This study aims to investigate the energy conduction mechanism of holmium laser lithotripsy based on the Gemini platform and validate the optimal lithotripsy parameters under this mechanism using an in vitro...Objective:This study aims to investigate the energy conduction mechanism of holmium laser lithotripsy based on the Gemini platform and validate the optimal lithotripsy parameters under this mechanism using an in vitro ureteral model.Methods:The Lumenis VersaPulse PowerSuite dual-wavelength laser system was employed,with a holmium laser wavelength of 2.1μm,power output of 0-80 W,pulse energy ranging from 0.2 to 3.5 J,and pulse frequency from 5 to 40 Hz.An in vitro thermal effect model of the holmium laser was established to simulate temperature changes in urinary stones under varying power levels,energy ranges,pulse frequencies,and irrigation rates.High-speed cameras and thermal imaging devices were used to observe and record the temperature of the stone and surrounding tissues during laser irradiation.Finite element analysis was integrated to simulate the energy conduction pathways of the holmium laser within the stone and ureteral wall,assessing whether localized high-temperature regions exceeded the thermal injury threshold.Results:Temperature in the stone fragmentation mode decreased significantly with increasing distance from the basket and higher irrigation rates,thereby reducing the risk of thermal injury.In fragmentation mode,both 276μm and 500μm core-diameter fibers generated significantly higher temperatures at the basket site compared to the free-running mode(P<0.05).No thermal injury was observed at irrigation rates≥15 ml/min across all parameter combinations;at 10 ml/min,only high-energy settings(3.5 J)approached the thermal injury threshold(50.3℃);at≤5 ml/min,high-energy settings(>1.5 J)consistently exceeded the danger threshold.The safest parameter combination was 0.5 J+5 Hz(at any irrigation rate).Within 5 min,temperatures at the stone surface-below,middle,and above the basket-reached 151.0℃±1.0℃,62.5℃±0.2℃,and 46.8℃±0.2℃,respectively,whereas the maximum temperature on the ureteral wall surface was only 49.5℃.The FEA results closely matched experimental observations,indicating that with 0.5 J+5 Hz(at any flow rate),laser energy is primarily confined within the stone,generating localized high-temperature zones(80℃-90℃)at the stone-ureter wall interface,which promotes stone fragmentation while effectively minimizing collateral tissue damage.Conclusion:The holmium laser energy conduction mechanism based on the Gemini platform is predominantly concentrated within the stone,exhibiting excellent directionality and depth penetration,enabling efficient lithotripsy while minimizing thermal damage to surrounding tissues.展开更多
Background： Oxygen-glucose deprivation-nutrition resumption （OGD-NR） models on H9c2 cells are commonly used in vitro models of simulated myocardial ischemia-reperfusion injury （M1RI）, but no study has assessed wh...Background： Oxygen-glucose deprivation-nutrition resumption （OGD-NR） models on H9c2 cells are commonly used in vitro models of simulated myocardial ischemia-reperfusion injury （M1RI）, but no study has assessed whether these methods for establishing in vitro models can effectively imitate the characteristics of MIRI in vivo. This experiment was designed to analyze the feasibility of six OGD-NR models of MIRI. Methods： By searching the PubMed database using the keywords ＂myocardial reperfusion injury H9c2 cells,＂ we obtained six commonly used OGD-NR in vitro models of MIRI performed on H9c2 cells from more than 400 published papers before January 30, 2017. For each model, control （C）, simulated ischemia （SI）, and simulated ischemia-reperfusion （SIR） groups were assigned, and cell morphology, lactate dehydrogenase （LDH） release, adenosine triphosphate （ATP） levels, reactive oxygen species （ROS）, mitochondrial membrane potential （MMP）, and inflammatory cytokines were examined to evaluate the characteristics of cell injury. Subsequently, a coculture system of cardiomyocyte-endothelial-macrophage was constructed. The coeulture system was dealt with SI and SIR treatments to test the effect on cardiomyocytes survival. Results： For models l, 2, 3, 4, 5, and 6, SI treatment caused morphological damage to cells, and subsequent SIR treatment did not cause further morphological damage. In the models 1, 2, 3, 4, 5 and 6, LDH release was significantly higher in the SI groups than that in the C group （P 〈 0.05）, and was significantly lower in the SIR groups than that in the SI groups （P 〈 0.05）, except tbr no significant differences in the LDH release between C, SI and SIR groups in model 6 receiving a 3-h SI treatment. In models 1, 2, 3, 4, 5, and 6, compared with the C group, ATP levels of the S1 groups significantly decreased （P 〈 0.05）, ROS levels increased （P 〈 0.05）, and MMP levels decreased （P 〈 0.05）. Compared with the SI group, ATP level of the SIR groups was significantly increased （P 〈 0,05）, and there was no significant ROS production, MMP collapse, and over inflammatory response in the SIR groups. In a coculture system of H9c2 cells-endothelial cells-macrophages, the proportion of viable H9c2 cells in the SIR groups was not reduced compared with the SI groups. Conclusion： All the six OGD-NR models on H9c2 cells in this experiment can not imitate the characteristics of MIRI in vivo and are not suitable for MIRl-related study.展开更多
Traumatic brain injuries are serious clinical incidents associated with some of the poorest outcomes in neurological practice.Coupled with the limited regenerative capacity of the brain,this has significant implicatio...Traumatic brain injuries are serious clinical incidents associated with some of the poorest outcomes in neurological practice.Coupled with the limited regenerative capacity of the brain,this has significant implications for patients,carers,and healthcare systems,and the requirement for life-long care in some cases.Clinical treatment currently focuses on limiting the initial neural damage with longterm care/support from multidisciplinary teams.Therapies targeting neuroprotection and neural regeneration are not currently available but are the focus of intensive research.Biomaterial-based interventions are gaining popularity for a range of applications including biomolecule and drug delive ry,and to function as cellular scaffolds.Experimental investigations into the development of such novel therapeutics for traumatic brain injury will be critically underpinned by the availability of appropriate high thro ughput,facile,ethically viable,and pathomimetic biological model systems.This represents a significant challenge for researchers given the pathological complexity of traumatic brain injury.Specifically,there is a concerted post-injury response mounted by multiple neural cell types which includes microglial activation and astroglial scarring with the expression of a range of growth inhibito ry molecules and cytokines in the lesion environment.Here,we review common models used for the study of traumatic brain injury(ranging from live animal models to in vitro systems),focusing on penetrating traumatic brain injury models.We discuss their relative advantages and drawbacks for the developmental testing of biomaterial-based therapies.展开更多
Liver injury is a common cause of drug approval withdrawal during drug development,pre-clinical research,and clinical treatment.If not properly treated,patients with severe liver injury can suffer from acute liver fai...Liver injury is a common cause of drug approval withdrawal during drug development,pre-clinical research,and clinical treatment.If not properly treated,patients with severe liver injury can suffer from acute liver failure or even death.Thus,utilization of the convenient in vitro hepatotoxicity assessment model for early detection of drug-induced hepatotoxicity is vital for drug development and safe personalized medication.Biomaterials(e.g.,hydrogels,nanofibers,decellularized liver matrix)and bioengineering technologies(e.g.,microarrays,micropatterns,3D printing,and microfluidics)have been applied for in vitro hepatotoxicity assessment models.This review summarizes the structure and functions of the liver as well as the components of in vitro hepatotoxicity assessment models.In addition,it highlights the latest advances in developing hepatotoxicity models with the ultimate goal of further clinical translation.展开更多
The use of three dimensional in vitro systems in cancer research is a promising path for developing effective anticancer therapies.The aim of this study was to engineer a functional 3-D in vitro model of normal and ca...The use of three dimensional in vitro systems in cancer research is a promising path for developing effective anticancer therapies.The aim of this study was to engineer a functional 3-D in vitro model of normal and cancerous cervical tissue.Normal epithelial and immortalized cervical epithelial carcinoma cell lines were used to construct 3-D artificial normal cervical and cervical cancerous tissues.De-epidermised dermis（DED） was used as a scaffold for both models.Morphological analyses were conducted by using hematoxylin and eosin staining and characteristics of the models were studied by analyzing the expression of different structural cytokeratins and differential protein marker MAX dimerisation protein 1（Mad1） using immunohistochemical technique.Haematoxylin and eosin staining results showed that normal cervical tissue had multi epithelial layers while cancerous cervical tissue showed dysplastic changes.Immunohistochemistry staining revealed that for normal cervix model cytokeratin 10 was expressed in the upper stratified layer of the epithelium while cytokeratin 5 was expressed mainly in the middle and basal layer.Cytokeratin 19 was weakly expressed in a few basal cells.Cervical cancer model showed cytokeratin 19 expression in different epithelial layers and weak or no expression for cytokeratin 5 and cytokeratin 10.Madl expression was detected in some suprabasal cells.The 3-D in vitro models showed stratified epithelial layers and expressed the same types and patterns of differentiation marker proteins as seen in corresponding in vivo tissue in either normal cervical or cervical cancerous tissue.These findings imply that they can serve as functional normal and cervical cancer models.展开更多
The human gut microbiota is widely considered to be a metabolic organ hidden within our bodies,playing a crucial role in the host’s physiology.Several factors affect its composition,so a wide variety of microbes resi...The human gut microbiota is widely considered to be a metabolic organ hidden within our bodies,playing a crucial role in the host’s physiology.Several factors affect its composition,so a wide variety of microbes residing in the gut are present in the world population.Individual excessive imbalances in microbial composition are often associated with human disorders and pathologies,and new investigative strategies to gain insight into these pathologies and define pharmaceutical therapies for their treatment are needed.In vitro models of the human gut microbiota are commonly used to study microbial fermentation patterns,community composition,and host-microbe interactions.Bioreactors and microfluidic devices have been designed to culture microorganisms from the human gut microbiota in a dynamic environment in the presence or absence of eukaryotic cells to interact with.In this review,we will describe the overall elements required to create a functioning,reproducible,and accurate in vitro culture of the human gut microbiota.In addition,we will analyze some of the devices currently used to study fermentation processes and relationships between the human gut microbiota and host eukaryotic cells.展开更多
Spinal cord injury affects millions of people around the world, however, limited therapies are available to improve the quality of life of these patients. Spinal cord injury is usually modeled in rats and mice using c...Spinal cord injury affects millions of people around the world, however, limited therapies are available to improve the quality of life of these patients. Spinal cord injury is usually modeled in rats and mice using contusion or complete transection models and this has led to a deeper understanding of the molecular and cellular complexities of the injury. However, it has not to date led to development of successful novel therapies, this is in part due to the complexity of the injury and the difficulty of deciphering the exact roles and interactions of different cells within this complex environment. Here we developed a collagen matrix that can be molded into the 3D tubular shape with a lumen and can hence support cell interactions in a similar architecture to a spinal cord. We show that astrocytes can be successfully grown on this matrix in vitro and when injured, the cells respond as they do in vivo and undergo reactive gliosis, one of the steps that lead to formation of a glial scar, the main barrier to spinal cord regeneration. In the future, this system can be used to quickly assess the effect of drugs on glial scar protein activity or to perform live imaging of labeled cells after exposure to drugs.展开更多
基金supported by the Volkswagen Foundation(Grant No.Az 99078 to DDC,ALT,and MT)funded by the Deutsche Forschungsgemeinschaft(DFG,German Research Foundation)under Germany’s Excellence Strategy–2082/1–390761711(to DDC)part of the research training group GRK 2415–Mechanobiology in Epithelial 3D Tissue Constructs(project number 363055819,to ALT and SJ).
文摘The global demand for in vitro respiratory airway models has surged due to the coronavirus disease 2019(COVID-19)pandemic.Current state-of-the-art models use polymer membranes to separate epithelial cells from other cell types,creating a nonphysiological barrier.In this study,we applied three-dimensional(3D)printing and bioprinting to develop an in vitro model where endothelial and epithelial cells were in direct contact,mimicking their natural arrangement.This proof-ofconcept model includes a culture chamber,with an endothelial bioink printed and perfused through an epithelial channel.In silico simulations of the air velocity within the channel revealed shear stress values ranging from 0.13 to 0.39 Pa,aligning with the desired in vivo shear stress observed in the bronchi regions(0.1–0.4 Pa).Biomechanical movements during resting breathing were mimicked by incorporating a textile mesh positioned away from the cell–cell interface.The epithelial channel demonstrated a capacity for compression and expansion of up to−14.7%and+6.4%,respectively.Microscopic images showed that the epithelial cells formed a uniform monolayer within the lumen of the channel close to the bioprinted endothelial cells.Our novel model offers a valuable tool for future research into respiratory diseases and potential treatments under conditions closely mimicking those in the lung.
基金supported by the Weston Brain Institute Rapid Response Grant,No.RR182093(to JR).
文摘The high metabolic demands of the brain require an efficient vascular system to be coupled with neural activity to supply adequate nutrients and oxygen.This supply is coordinated by the action of neurons,glial and vascular cells,known collectively as the neurovascular unit,which temporally and spatially regulate local cerebral blood flow through a process known as neurovascular coupling.In many neurodegenerative diseases,changes in functions of the neurovascular unit not only impair neurovascular coupling but also permeability of the blood-brain barrier,cerebral blood flow and clearance of waste from the brain.In order to study disease mechanisms,we need improved physiologicallyrelevant human models of the neurovascular unit.Advances towards modeling the cellular complexity of the neurovascular unit in vitro have been made using stem-cell derived organoids and more recently,vascularized organoids,enabling intricate studies of non-cell autonomous processes.Engineering and design innovations in microfluidic devices and tissue engineering are progressing our ability to interrogate the cerebrovasculature.These advanced models are being used to gain a better understanding of neurodegenerative disease processes and potential therapeutics.Continued innovation is required to build more physiologically-relevant models of the neurovascular unit encompassing both the cellular complexity and designed features to interrogate neurovascular unit functionality.
基金Project supported by the National Basic Research Program of China （Grant No.2006CB500702）, the National Natural Science Foundation of China （Grant No.30570590）, and the Science Foundation of Shanghai Municipal Commission of Science and Technology （Grant No.03JC14030）
文摘Neural stem cell has a potential to differentiate into neurons, astrocytes and oligodendrocytes. It provides an in vitro model to screen herbal medicines on the cellular differentiation and development level. In this work, active component from gypenosides and soyasaponins was prepared to investigate their effects on the differentiation of neural stem cells.. Both gypenosides and soyasaponins promote the differentiation of neural stem cells. This method provides speed and practicality for screening effective herbal medicine. It is well suited for studying the mechanism of cell differentiation and development.
文摘AIM:To globally compare the gene expression profiles during the capillary morphogenesis of human microvascular endothelial cells (HMVECs) in an in vitro angiogeness system with affymetrix oligonucleotide array. METHODS: A microcarrier-based in vitro angiogenesis system was developed, in which ECs migrated into the matrix, proliferated, and formed capillary sprouts. The sprouts elongated, branched and formed networks. The total RNA samples from the HMVECs at the selected time points (0.5, 24, and 72 h) during the capillary morphogenesis were used for microarray analyses, and the data were processed with the softwares provided by the manufacturers. The expression patterns of some genes were validated and confirmed by semi-quantitative RT-PCR. The regulated genes were grouped based on their molecular functions and expression patterns, and among them the expression of chemokines and chemokine receptors was specially examined and their functional implications were analyzed. RESULTS: A total of 1 961 genes were up- or downreg-ulated two-folds or above, and among them, 468 genes were up- or down-regulated three-folds or above. The regulated genes could be grouped into categories based on their molecular functions, and were also clustered into six groups based on their patterns of expression. As for chemokines and chemokine receptors, CXCL1/GRO-α, CXCL2/GRO-β, CXCL5/ENA-78, CXCL6/GCP2, IL-8/CXCL8, CXCL12/SDF-1, CXCL9/Mig, CXC11/ITAC, OOCL1/fractalkine, CCL2/MCP-1, CCL3, CCL5/RANTES, CCL7, CCL15, CCL21, CCL23, CCL28, and CCR1, CCR9, CXCR4 were identified. Moreover, these genes demonstrated different changing patterns during the capillary morphogenesis, which implied that they might have different roles in the sequential process. Among the chemokines identified, CCL2/MCP-1, CCL5/RANTES and CX3CL1 were specially up-regulated at the 24-h time point when the sprouting characterized the morphological change. It was thus suggested that they might exert crucial roles at the early stage of angiogenesis. CONCLUSION: The present study demonstrates a global profile of gene expression during endothelial capillary morphogenesis, and the results provide us much information about the molecular mechanisms of angiogenesis, with which further evaluation of individual genes can be conducted.
基金Supported by:Scientific and Technological Foundation of the National Administration of Traditional Chinese Medicine of China,No.02-03LP41the Scientific and Technological Key Project of Guangdong Province,No. 2006B35630007
文摘BACKGROUND： Neuronal loss, synapse mutilation, and increasing malnourished axons are pathologically related to Alzheimer＇s disease. Microtubule-associated protein 2 （MAP2） is of importance for neuronal, axonal, and dendritic generation, extension, and stabilization, as well as for the regulation of synaptic plasticity. OBJECTIVE： To investigate the antagonistic effects of natural-cerebrolysin-containing serum on beta amyloid protein 1-40 （Aβ1-40）-induced neurotoxicity from the standpoints of cell proliferation, synaptogenesis, and cytoskeleton formation （MAP2 expression）. DESIGN, TIME AND SETTING： A paralleled, controlled, neural cell, and molecular biology experiment was performed at the Institute of Integrated Chinese and Western Medicine, Shenzhen Hospital, Southern Medical University between February 2006 and April 2008. MATERIALS： PC12 cells, derived from the rat central nervous system, were purchased from Shanghai Institute of Cell Biology, Chinese Academy of Sciences, China. A β1-40 was provided by Sigma, USA. Natural-cerebrolysin was provided by Shenzhen Institute of Integrated Chinese and Western Medicine, China. The natural-cerebrolysin was predominantly composed of Renshen （Radix Ginseng）, Tianma （Rhizoma Gastrodiae）, and Yixingye （Ginkgo Leaf） in a proportion of 1：2：2. Following conventional water extraction technology, an extract （1：20） was prepared. Each gram of extract equaled 20 grams of crude drug. In a total of 12 adult male New Zealand rabbits, six underwent intragastric administration of natural-cerebrolysin extract for 1 month to prepare natural-cerebrolysin-containing serum, and the remaining six rabbits received intragastric administration of physiological saline to prepare normal blank serum. METHODS： An AIzheimer＇s disease in vitro model was induced in PC12 cells using Aβ1-40. The cells were incubated with varying doses of natural-cerebrolysin-containing serum （2.5%, 5%, and 10%）. Normal blank serum-treated PC12 cells served as a blank control group. MAIN OUTCOME MEASURES： Through the use of inverted phase contrast microscope, cell morphology and neurite growth were observed, neurite length was measured, and the percentage of neurite-positive cells was calculated. Cell proliferation rate was determined by MTT assay, and MAP 2 expression was detected by fluorescent immunocytochemistry. RESULTS： Following Aβ1-40 treatments, some PC12 cells were apoptotic/dying, and only a few short neurites were observed. Following interventions with natural-cerebrolysin-containing serum, the PC12 cells proliferated, there was an increased number of neurites, and neurite length was enhanced. After middle- and high-dose natural-cerebrolysin treatments, the percentage of neurite-positive cells, as well as the average length of neurites, was significantly greater than the normal blank serum-treated PC12 cells （P 〈 0.05 or P 〈 0.01）. Compared with the blank control group, MAP2 expression in the Aβ1-40-treated PC12 cells was significantly inhibited, and the cell proliferation rate was significantly decreased （P 〈 0.01）. Following incubations with natural-cerebrolysin-containing serum, MAP2 expression and cell proliferation rate in the PC12 cells were significantly increased in a dose-dependent manner, compared with treatments with blank control serum （P 〈 0.05 or P 〈 0.01 ）. CONCLUSION： Natural-cerebrolysin exhibited antagonistic effects on neurotoxicity in Aβ1-40 induced Alzheimer＇s disease in vitro models. These effects were likely related to cell proliferation and the upregulation of intracellular MAP2 expression.
基金supported by the SET foundation(Stiftung zur Forderung der Erforschung von Ersatz-und Erganzungsmethoden zur Einschrankung von Tierversuchen)project 060 to Winfried Neuhaus and Marco Metzger
文摘There is an urgent and tremendous need for human dis- ease models in drug development in order to improve pre- clinical predictability. In the case of brain disorders drugs have to cross the blood-brain barrier （BBB） to enter the central nervous system （CNS）. It was estimated that more than 95% of the drugs cannot cross the BBB.
文摘The aim of this work was to develop an in vitro model to study mechanical compression effects on cartilage. A pressure-controlled compression device was used in this study. Cartilage explants obtained from human knee were compressed at 1MPa/1Hz for 7 hours (30 min ON, 30 min OFF) under normoxia (5% CO2, 21% O2) or hypoxia (5% CO2, 5% O2). Cell viability was analyzed while nitric oxide (NO) and glycosaminoglycans (GAG) release was assayed in culture media. Mechanical stimulation increased NO production and GAG release by human cartilage explants under normoxia and hypoxia culture. In normoxia and hypoxia conditions, mechanical stimulation alters human OA cartilage metabolism. There is also, an increase in matrix degradation after compression, as shown by levels of GAG found in culture media. This study put in evidence the importance of mechanical compression in the progression of the osteoarthritis and present and in vitro model for mechanobiological and pharmacological studies.
文摘Background:Risk factors for the etiology of post-weaning diarrhea,a major problem in swine industry associated with enormous economic losses,remain to be fully elucidated.In concordance with the ethical concerns raised by animal experiments,we developed a new in vitro model of the weaning piglet colon(MPigut-IVM)including a mucin bead compartment to reproduce the mucus surface from the gut to which gut microbes can adhere.Results:Our results indicated that the MPigut-IVM is able to establish a representative piglet archaeal and bacterial colon microbiota in terms of taxonomic composition and function.The MPigut-IVM was consequently used to investigate the potential effects of feed deprivation,a common consequence of weaning in piglets,on the microbiota.The lack of nutrients in the MPigut-IVM led to an increased abundance of Prevotellaceae and Escherichia-Shigella and a decrease in Bacteroidiaceae and confirms previous in vivo findings.On top of a strong increase in redox potential,the feed deprivation stress induced modifications of microbial metabolite production such as a decrease in acetate and an increase in proportional valerate,isovalerate and isobutyrate production.Conclusions:The MPigut-IVM is able to simulate luminal and mucosal piglet microbiota and represent an innovative tool for comparative studies to investigate the impact of weaning stressors on piglet microbiota.Besides,weaning-associated feed deprivation in piglets provokes disruptions of MPigut-IVM microbiota composition and functionality and could be implicated in the onset of post-weaning dysbiosis in piglets.
基金sponsored by the National Natural Science Foundation of China [No.81372949]the Young Scholar Scientific Research Foundation of China CDC [No.2016A206]
文摘Objective To comparatively study the toxicity of four metal-containing nanoparticles(MNPs) and their chemical counterparts to the air-blood barrier(ABB) permeability using an in vitro model.Methods ABB model, which was developed via the co-culturing of A549 and pulmonary capillary endothelium, was exposed to spherical CuO-NPs(divided into CuO-40, CuO-80, and CuO-100 based on particle size), nano-Al2O3(sheet and short-rod-shaped), nano-ZnO, nano-Pb S, CuSO4, Al2(SO4)3, Zn(CH3COO)2, and Pb(NO3)2 for 60 min.Every 10 min following exposure, the cumulative cleared volume(ΔTCL) of Lucifer yellow by the model was calculated.A clearance curve was established using linear regression analysis of ΔTCL versus time.Permeability coefficient(P) was calculated based on the slope of the curve to represent the degree of change in the ABB permeability.Results The results found the increased P values of CuO-40, CuO-80, sheet, and short-rod-shaped nano-Al2O3, Al2(SO4)3, and Pb(NO3)2.Among them, small CuO-40 and CuO-80 were stronger than CuO-100 and CuSO4;no difference was observed between Al2(SO4)3 and sheet and short-rod-shaped nano-Al2O3;and nano-Pb S was slightly weaker than Pb(NO3)2.So clearly the MNPs possess diverse toxicity.Conclusion ABB permeability abnormality means pulmonary toxicity potential.More studies are warranted to understand MNPs toxicity and ultimately control the health hazards.
基金supported by grants of the FWO,the research council of the VUB and the European Union
文摘Direct intercellular communication mediated by gap junctions constitutes a major regulatory platform in the control of hepatic homeostasis.Hepatocellular gap junctions are composed of two hemichannels of adjacent cells which are built up by connexin proteins,in casu Cx32.Mathieu Vinken,Pofessor at the Department of Toxicology of the Free University BrusselsBelgium,was one of the first investigators to demonstrate that hepatic connexin expression is controlled by epigenetic mechanisms.In particular,he found that inhibitors of histone deacetylase enzymes enhance Cx32 production and gap junction activity in cultures of primary hepatocytes,a finding that is of importance for liver-based in vitro modelling.Professor Dr.Mathieu Vinken's recent work is focussed on the elucidation of the role of connexin proteins and their channels in the hepatocyte life cycle.Specific attention is paid to apoptosis in this context,whereby it has been found that Cx32 hemichannels control the termination of induced cell death in cultures of primary hepatocytes. Overall,Professor Dr.Mathieu Vinken's research can be considered as an important contribution to the field of hepatic connexin physiology.
基金funding from the European Union’s Hori-zon 2020 FET Open programme under grant agreement No.964452.
文摘Chronic kidney diseases affect a significant portion of the global population and their prevalence is expected to increase in the coming years.Advanced in vitro models are crucial for understanding disease onset and for improving drug testing.Emerging strategies have enhanced the accuracy of these models by incorporating 3D culture and perfusion systems.Notably,efforts have focused on modeling the nephron,particularly endothelialized and epithelialized tubular structures,with perfusion to simulate toxin exchange for nephrotoxicity testing.New approaches combining biomaterials with patient-derived kidney epithelial cells show promise for high-throughput personalized drug screening.However,these methods often rely on decellularized extracellular matrix materials,such as Matrigel®and collagen,which suffer from batch-to-batch variability.To address reproducibility issues,we used norbornene-functionalized alginate to produce peptide-functionalized thiol-ene crosslinked hydrogels.By varying the composition of crosslinkers and peptide functionalization,we tuned the cell interaction with the hydrogels.The rapid reaction kinetics enabled the bioprinting of cell-laden tubular structures using microfluidic bioprinting,without the need for ionic crosslinking,by adapting the printer with UV irradiation at the nozzle.The bioprinted fibers successfully formed monolayers,indicating their potential for creating advanced kidney in vitro models.Thiol-ene crosslinked hydrogels proved to be highly tunable and adaptable to microfluidic bioprinting,demonstrating significant promise for further application to create kidney in vitro models.
文摘Background We investigated differences in intracranial embolus distribution through communicating arteries in relation to supra-aortic vessel(SAV)patency.Methods For this experimental analysis,we created a silicone model of the extracranial and intracranial circulations using a blood-mimicking fluid under physiological pulsatile flow.We examined the sequence of embolus lodgment on injecting 104 frangible clot analogues(406 emboli)through the right internal carotid artery(CA)as SAV patency changed:(a)all SAV patent(baseline),(b)emboli from a CA occlusion,(c)emboli contralateral to a CA occlusion and(d)occlusion of the posterior circulation.The statistical analysis included a descriptive analysis of thrombi location after occlusion(absolute and relative frequencies).Sequences of occlusions were displayed in Sankey flow charts for the four SAV conditions.Associations between SAV conditions and occlusion location were tested by Fisher’s exact test.Two-sided p values were compared with a significance level of 0.05.Results The total number of emboli was 406(median fragments/clot:4(IQR:3-5)).Embolus lodgment was dependent on SAV patency(p<0.0001).In all scenarios,embolism lodging in the anterior cerebral artery(ACA)occurred after a previous middle cerebral artery(MCA)embolism(MCA first lodge:96%,100/104).The rate of ipsilateral ACA embolism was 28.9%(28/97)at baseline,decreasing significantly when emboli originated from an occluded CA(16%,14/88).There were more bihemispheric embolisations in cases of contralateral CA occlusion(37%,45/122),with bilateral ACA embolisms preceding contralateral MCA embolism in 56%of cases(14/25 opposite MCA and ACA embolism).Conclusions All emboli in the ACA occurred after a previous ipsilateral MCA embolism.Bihemispheric embolisms were rare,except when there was a coexisting occlusion in either CA,particularly in cases of a contralateral CA occlusion.
基金Open Access funding enabled and organized by Projekt DEAL.
文摘The liver hosts a variety of immune cells while creating a tolerogenic environment under homeostatic conditions.However,most chronic liver diseases shift toward inflammation over time.Understanding and intercepting the crosstalk between various immune cells and liver tissue is crucial,as it is often the rate-limiting factor in preclinical drug development.Owing to significant interspecies differences in liver immunology,human models,such as classical cocultures or organogenesis-inspired liver organoids with immune compartments,are becoming essential for advancing the field.Therefore,this review evaluates human-specific models of hepatic-immune crosstalk and assesses a range of models from basic 2D cultures to microphysiological systems(MPSs)and advanced multitissue organoids.It serves as a guide for experimentalists to identify suitable approaches.For example,traditional cocultures offer robustness,reductionist approaches,and modularity but have limited spatial fidelity and cell heterogeneity.In contrast,multitissue organoids inspired by mammalian ontogeny are created from pluripotent stem cells and integrate multiple tissue niche-constituting cells,which include Kupffer-like cells.In conclusion,this review discusses progress in human liver immunology modeling and highlights limitations and numerous untapped opportunities.These include the potential to model in vitro autoimmunity and more complex myeloid inflammatory responses,incorporating contributions from embryonic tissue and bone marrow.Additionally,future in vitro models may include hard-to-culture populations such as neutrophils.
文摘Objective:This study aims to investigate the energy conduction mechanism of holmium laser lithotripsy based on the Gemini platform and validate the optimal lithotripsy parameters under this mechanism using an in vitro ureteral model.Methods:The Lumenis VersaPulse PowerSuite dual-wavelength laser system was employed,with a holmium laser wavelength of 2.1μm,power output of 0-80 W,pulse energy ranging from 0.2 to 3.5 J,and pulse frequency from 5 to 40 Hz.An in vitro thermal effect model of the holmium laser was established to simulate temperature changes in urinary stones under varying power levels,energy ranges,pulse frequencies,and irrigation rates.High-speed cameras and thermal imaging devices were used to observe and record the temperature of the stone and surrounding tissues during laser irradiation.Finite element analysis was integrated to simulate the energy conduction pathways of the holmium laser within the stone and ureteral wall,assessing whether localized high-temperature regions exceeded the thermal injury threshold.Results:Temperature in the stone fragmentation mode decreased significantly with increasing distance from the basket and higher irrigation rates,thereby reducing the risk of thermal injury.In fragmentation mode,both 276μm and 500μm core-diameter fibers generated significantly higher temperatures at the basket site compared to the free-running mode(P<0.05).No thermal injury was observed at irrigation rates≥15 ml/min across all parameter combinations;at 10 ml/min,only high-energy settings(3.5 J)approached the thermal injury threshold(50.3℃);at≤5 ml/min,high-energy settings(>1.5 J)consistently exceeded the danger threshold.The safest parameter combination was 0.5 J+5 Hz(at any irrigation rate).Within 5 min,temperatures at the stone surface-below,middle,and above the basket-reached 151.0℃±1.0℃,62.5℃±0.2℃,and 46.8℃±0.2℃,respectively,whereas the maximum temperature on the ureteral wall surface was only 49.5℃.The FEA results closely matched experimental observations,indicating that with 0.5 J+5 Hz(at any flow rate),laser energy is primarily confined within the stone,generating localized high-temperature zones(80℃-90℃)at the stone-ureter wall interface,which promotes stone fragmentation while effectively minimizing collateral tissue damage.Conclusion:The holmium laser energy conduction mechanism based on the Gemini platform is predominantly concentrated within the stone,exhibiting excellent directionality and depth penetration,enabling efficient lithotripsy while minimizing thermal damage to surrounding tissues.
基金The work was supported by grants from the major projects of Scientific and Research Found of Plastic Surgery Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College （No. Z2017001） and the National Natural Science Foundation of China （No. 81470019）.
文摘Background： Oxygen-glucose deprivation-nutrition resumption （OGD-NR） models on H9c2 cells are commonly used in vitro models of simulated myocardial ischemia-reperfusion injury （M1RI）, but no study has assessed whether these methods for establishing in vitro models can effectively imitate the characteristics of MIRI in vivo. This experiment was designed to analyze the feasibility of six OGD-NR models of MIRI. Methods： By searching the PubMed database using the keywords ＂myocardial reperfusion injury H9c2 cells,＂ we obtained six commonly used OGD-NR in vitro models of MIRI performed on H9c2 cells from more than 400 published papers before January 30, 2017. For each model, control （C）, simulated ischemia （SI）, and simulated ischemia-reperfusion （SIR） groups were assigned, and cell morphology, lactate dehydrogenase （LDH） release, adenosine triphosphate （ATP） levels, reactive oxygen species （ROS）, mitochondrial membrane potential （MMP）, and inflammatory cytokines were examined to evaluate the characteristics of cell injury. Subsequently, a coculture system of cardiomyocyte-endothelial-macrophage was constructed. The coeulture system was dealt with SI and SIR treatments to test the effect on cardiomyocytes survival. Results： For models l, 2, 3, 4, 5, and 6, SI treatment caused morphological damage to cells, and subsequent SIR treatment did not cause further morphological damage. In the models 1, 2, 3, 4, 5 and 6, LDH release was significantly higher in the SI groups than that in the C group （P 〈 0.05）, and was significantly lower in the SIR groups than that in the SI groups （P 〈 0.05）, except tbr no significant differences in the LDH release between C, SI and SIR groups in model 6 receiving a 3-h SI treatment. In models 1, 2, 3, 4, 5, and 6, compared with the C group, ATP levels of the S1 groups significantly decreased （P 〈 0.05）, ROS levels increased （P 〈 0.05）, and MMP levels decreased （P 〈 0.05）. Compared with the SI group, ATP level of the SIR groups was significantly increased （P 〈 0,05）, and there was no significant ROS production, MMP collapse, and over inflammatory response in the SIR groups. In a coculture system of H9c2 cells-endothelial cells-macrophages, the proportion of viable H9c2 cells in the SIR groups was not reduced compared with the SI groups. Conclusion： All the six OGD-NR models on H9c2 cells in this experiment can not imitate the characteristics of MIRI in vivo and are not suitable for MIRl-related study.
基金funded by awards from the EPSRC Doctoral Training Centre in Regenerative Medicine and an NHS bursary。
文摘Traumatic brain injuries are serious clinical incidents associated with some of the poorest outcomes in neurological practice.Coupled with the limited regenerative capacity of the brain,this has significant implications for patients,carers,and healthcare systems,and the requirement for life-long care in some cases.Clinical treatment currently focuses on limiting the initial neural damage with longterm care/support from multidisciplinary teams.Therapies targeting neuroprotection and neural regeneration are not currently available but are the focus of intensive research.Biomaterial-based interventions are gaining popularity for a range of applications including biomolecule and drug delive ry,and to function as cellular scaffolds.Experimental investigations into the development of such novel therapeutics for traumatic brain injury will be critically underpinned by the availability of appropriate high thro ughput,facile,ethically viable,and pathomimetic biological model systems.This represents a significant challenge for researchers given the pathological complexity of traumatic brain injury.Specifically,there is a concerted post-injury response mounted by multiple neural cell types which includes microglial activation and astroglial scarring with the expression of a range of growth inhibito ry molecules and cytokines in the lesion environment.Here,we review common models used for the study of traumatic brain injury(ranging from live animal models to in vitro systems),focusing on penetrating traumatic brain injury models.We discuss their relative advantages and drawbacks for the developmental testing of biomaterial-based therapies.
基金supports from General Program from the National Natural Science Foundation of China(No.31871016)the National Key Research and Development Program(2016YFC1101302)from the Ministry of Science and Technology of China.
文摘Liver injury is a common cause of drug approval withdrawal during drug development,pre-clinical research,and clinical treatment.If not properly treated,patients with severe liver injury can suffer from acute liver failure or even death.Thus,utilization of the convenient in vitro hepatotoxicity assessment model for early detection of drug-induced hepatotoxicity is vital for drug development and safe personalized medication.Biomaterials(e.g.,hydrogels,nanofibers,decellularized liver matrix)and bioengineering technologies(e.g.,microarrays,micropatterns,3D printing,and microfluidics)have been applied for in vitro hepatotoxicity assessment models.This review summarizes the structure and functions of the liver as well as the components of in vitro hepatotoxicity assessment models.In addition,it highlights the latest advances in developing hepatotoxicity models with the ultimate goal of further clinical translation.
基金supported by the Middlesex University,particularly in the award of a Postgraduate Research Studentship that provided the necessary financial support for this research
文摘The use of three dimensional in vitro systems in cancer research is a promising path for developing effective anticancer therapies.The aim of this study was to engineer a functional 3-D in vitro model of normal and cancerous cervical tissue.Normal epithelial and immortalized cervical epithelial carcinoma cell lines were used to construct 3-D artificial normal cervical and cervical cancerous tissues.De-epidermised dermis（DED） was used as a scaffold for both models.Morphological analyses were conducted by using hematoxylin and eosin staining and characteristics of the models were studied by analyzing the expression of different structural cytokeratins and differential protein marker MAX dimerisation protein 1（Mad1） using immunohistochemical technique.Haematoxylin and eosin staining results showed that normal cervical tissue had multi epithelial layers while cancerous cervical tissue showed dysplastic changes.Immunohistochemistry staining revealed that for normal cervix model cytokeratin 10 was expressed in the upper stratified layer of the epithelium while cytokeratin 5 was expressed mainly in the middle and basal layer.Cytokeratin 19 was weakly expressed in a few basal cells.Cervical cancer model showed cytokeratin 19 expression in different epithelial layers and weak or no expression for cytokeratin 5 and cytokeratin 10.Madl expression was detected in some suprabasal cells.The 3-D in vitro models showed stratified epithelial layers and expressed the same types and patterns of differentiation marker proteins as seen in corresponding in vivo tissue in either normal cervical or cervical cancerous tissue.These findings imply that they can serve as functional normal and cervical cancer models.
基金supported by the BIOMEMBRANE project (M-ERA.net 2 project 4246)the KERAPACK project (MANUNET MNET 17/NMAT-0060)+2 种基金the PRA_2018_68 (grant supported by the University of Pisa)MIT-UNIPI project (grant supported by the University of Pisa and the MIT)the support of the Additive Manufacturing Cross-Lab of the Department of Information Engineering of the University of Pisa
文摘The human gut microbiota is widely considered to be a metabolic organ hidden within our bodies,playing a crucial role in the host’s physiology.Several factors affect its composition,so a wide variety of microbes residing in the gut are present in the world population.Individual excessive imbalances in microbial composition are often associated with human disorders and pathologies,and new investigative strategies to gain insight into these pathologies and define pharmaceutical therapies for their treatment are needed.In vitro models of the human gut microbiota are commonly used to study microbial fermentation patterns,community composition,and host-microbe interactions.Bioreactors and microfluidic devices have been designed to culture microorganisms from the human gut microbiota in a dynamic environment in the presence or absence of eukaryotic cells to interact with.In this review,we will describe the overall elements required to create a functioning,reproducible,and accurate in vitro culture of the human gut microbiota.In addition,we will analyze some of the devices currently used to study fermentation processes and relationships between the human gut microbiota and host eukaryotic cells.
文摘Spinal cord injury affects millions of people around the world, however, limited therapies are available to improve the quality of life of these patients. Spinal cord injury is usually modeled in rats and mice using contusion or complete transection models and this has led to a deeper understanding of the molecular and cellular complexities of the injury. However, it has not to date led to development of successful novel therapies, this is in part due to the complexity of the injury and the difficulty of deciphering the exact roles and interactions of different cells within this complex environment. Here we developed a collagen matrix that can be molded into the 3D tubular shape with a lumen and can hence support cell interactions in a similar architecture to a spinal cord. We show that astrocytes can be successfully grown on this matrix in vitro and when injured, the cells respond as they do in vivo and undergo reactive gliosis, one of the steps that lead to formation of a glial scar, the main barrier to spinal cord regeneration. In the future, this system can be used to quickly assess the effect of drugs on glial scar protein activity or to perform live imaging of labeled cells after exposure to drugs.
