Engineered cardiac constructs(ECC)aid in the progression of regenerative medicine,disease modeling and targeted drug delivery to adjust and aim the release of remedial combination as well as decrease the side effects ...Engineered cardiac constructs(ECC)aid in the progression of regenerative medicine,disease modeling and targeted drug delivery to adjust and aim the release of remedial combination as well as decrease the side effects of drugs.In this research,polycaprolactone/gold nanoparticles(PCL/GNPs)three-dimensional(3D)composite scaffolds were manufactured by 3D printing using the fused deposition modeling(FDM)method and then coated with gelatin/spironolactone(GEL/SPL).Scanning electron microscopy(SEM)and Fourier transform-infrared spectroscopy(FTIR–ATR)were applied to characterize the samples.Furthermore,drug release,biodegradation,behavior of the myoblasts(H9C2)cell line,and cytotoxicity of the 3D scaffolds were evaluated.The microstructural observation of the scaffolds reported interconnected pores with 150–300µm in diameter.The 3D scaffolds were degraded significantly after 28 days of immersion in stimulated body fluid(SBF),with the maximum rate of GEL-coated 3D scaffolds.SPL release from cross-linked GEL coating demonstrated the excess of drug release over time,and according to the control release systems,the drug delivery systems(DDS)went into balance after the 14th day.In addition,cell culture study showed that with the addition of GNPs,the proliferation of(H9C2)was enhanced,and with GEL/SPL coating the cell attachment and viability were improved significantly.These findings suggested that PCL/GNPs 3D scaffolds coated with GEL/SPL can be an appropriate choice for myocardial tissue engineering.展开更多
Given the limited spontaneous repair that follows cartilage injury, demand is growing for tissue engi- neering approaches for cartilage regeneration. There are two major applications for tissue-engineered cartilage. O...Given the limited spontaneous repair that follows cartilage injury, demand is growing for tissue engi- neering approaches for cartilage regeneration. There are two major applications for tissue-engineered cartilage. One is in orthopedic surgery, in which the engineered cartilage is usually used to repair cartilage defects or loss in an articular joint or meniscus in order to restore the joint function. The other is for head and neck reconstruction, in which the engineered cartilage is usually applied to repair cartilage defects or loss in an auricle, trachea, nose, larynx, or eyelid. The challenges faced by the engineered car- tilage for one application are quite different from those faced by the engineered cartilage for the other application. As a result, the emphases of the engineering strategies to generate cartilage are usually quite different for each application. The statuses of preclinical animal investigations and of the clinical translation of engineered cartilage are also at different levels for each application. The aim of this review is to provide an opinion piece on the challenges, current developments, and future directions for cartilage engineering for both applications.展开更多
Tissue-engineering bone with porous β-tricalcium phosphate (β-TCP) ceramic and autologous bone marrow mesenchymal stem cells (MSC) was constructed and the effect of this composite on healing of segmental bone defect...Tissue-engineering bone with porous β-tricalcium phosphate (β-TCP) ceramic and autologous bone marrow mesenchymal stem cells (MSC) was constructed and the effect of this composite on healing of segmental bone defects was investigated. 10-15 ml bone marrow aspirates were harvested from the iliac crest of sheep, and enriched for MSC by density gradient centrifugation over a Percoll cushion (1.073 g/ml). After cultured and proliferated, tissue-engineering bones were constructed with these cells seeded onto porous β-TCP, and then the constructs were implanted in 8 sheep left metatarsus defect (25 mm in length) as experimental group. Porous β-TCP only were implanted to bridge same size and position defects in 8 sheep as control group, and 25 mm segmental bone defects of left metatarsus were left empty in 4 sheep as blank group. Sheep were sacrificed on the 6th, 12th, and 24th week postoperatively and the implants samples were examined by radiograph, histology, and biomechanical test. The 4 sheep in blank group were sacrificed on the 24th week postoperatively. The results showed that new bone tissues were observed either radiographic or histologically at the defects of experimental group as early as 6th week postoperatively, but not in control group, and osteoid tissue, woven bone and lamellar bone occurred earlier than in control group in which the bone defects were repaired in “creep substitution” way, because of the new bone formed in direct manner without progression through a cartilaginous intermediate. At the 24th week, radiographs and biomechanical test revealed an almost complete repair of the defect of experimental group, only partly in control group. The bone defects in blank group were non-healing at the 24th week. It was concluded that engineering bones constructed with porous β-TCP and autologous MSC were capable of repairing segmental bone defects in sheep metatarsus beyond “creep substitution” way and making it healed earlier. Porous β-TCP being constituted with autologous MSC may be a good option in healing critical segmental bone defects in clinical practice and provide insight for future clinical repair of segmental defect.展开更多
Multiple sclerosis (MS) is characterized by chronic,slowly expanding lesions with the accumulation of myeloid cells,which lead to brain atrophy and progressive disability.The role of mitochondria,especially mitochondr...Multiple sclerosis (MS) is characterized by chronic,slowly expanding lesions with the accumulation of myeloid cells,which lead to brain atrophy and progressive disability.The role of mitochondria,especially mitochondrial respiratory complexes and metabolites,in controlling myeloid immune responses,is well-documented but not fully understood in diseases of the central nervous system (CNS).The groundbreaking study by Prof.Peruzzotti-Jametti et al.[1],entitled"Mitochondrial complexⅠactivity in microglia sustains neuroinflammation"published in Nature,delves into the intricate dynamics between mitochondrial function within microglia and the perpetuation of chronic neuroinflammation,specifically in MS.The core point of their investigation is the hypothesis that mitochondrial complexⅠ(CI) activity,through a mechanism known as reverse electron transport (RET),generates reactive oxygen species (ROS) in microglia,thereby sustaining inflammatory response in the CNS.This increases ROS production from the mitochondria,which is thought to be a crucial factor in the maintenance of a pro-inflammatory state in the microglia,contributing to the pathology of MS and similar neuroinflammatory diseases.展开更多
BACKGROUND Human periodontal ligament stem cells(PDLSCs)regenerate oral tissue.In vitro expansion causes replicative senescence in stem cells.This causes intracellular reactive oxygen species(ROS)accumulation,which ca...BACKGROUND Human periodontal ligament stem cells(PDLSCs)regenerate oral tissue.In vitro expansion causes replicative senescence in stem cells.This causes intracellular reactive oxygen species(ROS)accumulation,which can impair stem cell function.Tissue engineering efficiency is reduced by exogenous ROS stimulation,which causes premature senescence under oxidative stress.Melatonin(MT),a powerful free radical scavenger,can delay PDLSCs senescence but may not maintain stemness under oxidative stress.This experiment examined the effects of hydrogen peroxide-induced oxidative stress on PDLSCs’apoptosis,senescence,and stemness.AIM To determine if MT can reverse the above effects along with the underlying molecular mechanisms involved.METHODS PDLSCs were isolated from human premolars and cultured in different conditions.Flow cytometry was used to characterize the cell surface markers of BACKGROUND Human periodontal ligament stem cells(PDLSCs)regenerate oral tissue.In vitro expansion causes replicative senescence in stem cells.This causes intracellular reactive oxygen species(ROS)accumulation,which can impair stem cell function.Tissue engineering efficiency is reduced by exogenous ROS stimulation,which causes premature senescence under oxidative stress.Melatonin(MT),a powerful free radical scavenger,can delay PDLSCs senescence but may not maintain stemness under oxidative stress.This experiment examined the effects of hydrogen peroxide-induced oxidative stress on PDLSCs’apoptosis,senescence,and stemness.AIM To determine if MT can reverse the above effects along with the underlying molecular mechanisms involved.METHODS PDLSCs were isolated from human premolars and cultured in different conditions.Flow cytometry was used to characterize the cell surface markers of differentiation,ROS,and senescence-associatedβ-galactosidase activity were assessed by various assays.Reverse transcription-polymerase chain reaction and western blot were used to measure the expression of genes and proteins related to stemness and senescence.RESULTS MT increases Yes-associated protein expression and maintains cell stemness in an induced inflammatory microenvironment,which may explain its therapeutic effects.We examined how MT affects PDLSCs aging and stemness and its biological mechanisms.CONCLUSION Our study reveals MT’s role in regulating oxidative stress in PDLSCs and Yes-associated protein-mediated activity,providing insights into cellular functions and new therapeutic targets for tissue regeneration.展开更多
The efficient clinical treatment of oral squamous cell carcinoma(OSCC)is still a challenge that demands the development of effective new drugs.Phenformin has been shown to produce more potent anti-tumor activities tha...The efficient clinical treatment of oral squamous cell carcinoma(OSCC)is still a challenge that demands the development of effective new drugs.Phenformin has been shown to produce more potent anti-tumor activities than metformin on different tumors,however,not much is known about the influence of phenformin on OSCC cells.We found that phenformin suppresses OSCC cell proliferation,and promotes OSCC cell autophagy and apoptosis to significantly inhibit OSCC cell growth both in vivo and in vitro.RNA-seq analysis revealed that autophagy pathways were the main targets of phenformin and identified two new targets DDIT4(DNA damage inducible transcript 4)and NIBAN1(niban apoptosis regulator 1).We found that phenformin significantly induces the expression of both DDIT4 and NIBAN1 to promote OSCC autophagy.Further,the enhanced expression of DDIT4 and NIBAN1 elicited by phenformin was not blocked by the knockdown of AMPK but was suppressed by the knockdown of transcription factor ATF4(activation transcription factor 4),which was induced by phenformin treatment in OSCC cells.Mechanistically,these results revealed that phenformin triggers endoplasmic reticulum(ER)stress to activate PERK(protein kinase R-like ER kinase),which phosphorylates the transitional initial factor eIF2,and the increased phosphorylation of eIF2 leads to the increased translation of ATF4.In summary,we discovered that phenformin induces its new targets DDIT4 and especially NIBAN1 to promote autophagic and apoptotic cell death to suppress OSCC cell growth.Our study supports the potential clinical utility of phenformin for OSCC treatment in the future.展开更多
Endo-periodontal lesions (EPLs) involve both the periodontium and pulp tissue and have complicated etiologies and pathogenic mechanisms,including unique anatomical and microbiological characteristics and multiple cont...Endo-periodontal lesions (EPLs) involve both the periodontium and pulp tissue and have complicated etiologies and pathogenic mechanisms,including unique anatomical and microbiological characteristics and multiple contributing factors.This etiological complexity leads to difficulties in determining patient prognosis,posing great challenges in clinical practice.Furthermore,EPL-affected teeth require multidisciplinary therapy,including periodontal therapy,endodontic therapy and others,but there is still much debate about the appropriate timing of periodontal therapy and root canal therapy.By compiling the most recent findings on the etiology,pathogenesis,clinical characteristics,diagnosis,therapy,and prognosis of EPL-affected teeth,this consensus sought to support clinicians in making the best possible treatment decisions based on both biological and clinical evidence.展开更多
Objective： Procyanidins （PC） are widely available natural polyphenols. The present study is designed to investigate if PC can inhibit angiogenesis in lung adenocarcinoma xenografts through crosslinking vascular ext...Objective： Procyanidins （PC） are widely available natural polyphenols. The present study is designed to investigate if PC can inhibit angiogenesis in lung adenocarcinoma xenografts through crosslinking vascular extracellular matrix （ECM） and preventing proteolysis by matrix metalloproteinases （MMPs）. Methods： Using the in vitro MMP-2 proteolysis and in vivo subcutaneous implantation models, we investigated if PC crosslinking inhibits MMP-mediated proteolysis. Using a cultured cell detachment assay, an in vitro angiogenesis assay, and a cell proliferation assay, we investigated if PC inhibits MMP-2-mediated endothelial cell detachment, angiogenesis, and cell proliferation, respectively. Using tumor xenografts, we evaluated if PC can inhibit growth of lung adenocarcinoma. Results： PC crosslink vascular ECM proteins, protecting them against proteolysis by MMPs in vitro and in vivo, protecting cultured human umbilical vein endothelial cells from detachment by MMP-2, and inhibiting in vitro angiogenesis. However, PC （0.75-100 μg/mL） did not inhibit vascular and tumor cells proliferation. PC injections （30 mg PC/kg bodyweight） in situ had anticancer effects on xenografts of lung adenocarcinoma, most likely by inhibiting angiogenesis during ECM proteolysis by MMPs. Conclusion： The results suggest that PC may be important MMP inhibitors that can be used as therapeutic anticancer agents.展开更多
Embryonic stem （ES） cells have the potential to develop into any type of tissue and are considered as a promising source of seeding cells for tissue engineering and transplantation therapy.The main catalyst for ES c...Embryonic stem （ES） cells have the potential to develop into any type of tissue and are considered as a promising source of seeding cells for tissue engineering and transplantation therapy.The main catalyst for ES cells differentiation is the growth into embryoid bodies （EBs）,which are utilized widely as the trigger of in vitro differentiation.In this study,a novel method for generating EBs from mouse ES cells through culture in collagen/Matrigel scaffolds was successfully established.When single ES cells were seeded in three dimensional collagen/Matrigel scaffolds,they grew into aggregates gradually and formed simple EBs with circular structures.After 7 days＇ culture,they formed into cystic EBs that would eventually differentiate into the three embryonic germ layers.Evaluation of the EBs in terms of morphology and potential to differentiate indicated that they were typical in structure and could generate various cell types;they were also able to form into tissue-like structures.Moreover,with introduction of ascorbic acid,ES cells differentiated into cardiomyocytes efficiently and started contracting synchronously at day 19.The results demonstrated that collagen/Matrigel scaffolds supported EBs formation and their subsequent differentiation in a single three dimensional environment.展开更多
Aim： To identify proteins induced by androgen in Sertoli cells during spermatogenesis. Methods： We analyzed protein profiles in TM4 Sertoli cells treated with dihydrotestosterone （DHT） using surface enhanced laser...Aim： To identify proteins induced by androgen in Sertoli cells during spermatogenesis. Methods： We analyzed protein profiles in TM4 Sertoli cells treated with dihydrotestosterone （DHT） using surface enhanced laser desorption ionization time-of-flight mass spectrometry （SELDI-TOF-MS）. Results： We found increases in the expression of a 5.0-kDa protein at 15 min, an 11.3-kDa protein at 24 h and 4.3 kDa, 5.7 kDa, 5.8 kDa, 9.95 kDa and 9.98 kDa proteins at 48 h after the treatment. In contrast, the expression of 6.3 kDa and 8.6 kDa proteins decreased at 30 min, and 4.9 kDa, 5.0 kDa, 12.4 kDa and 19.8 kDa proteins at 48 h after the treatment. The ll.3-kDa protein was identified as macrophage migration inhibitory factor （MIF） known to having various functions. The 9.98-kDa protein was identified as calgizzarin related to calcium channels. The timing of their expression suggests that MIF and calgizzarin are involved in late regulation of spermatogenesis in Sertoli cells by androgen. Conclusion： MIF and calgizzarin are two important androgen-responsive proteins produced by Sertoli cells and they might play a role in regulating spermatogenesis.展开更多
Several studies have demonstrated that selective serotonin reuptake inhibitor antidepressants can promote neuronal cell proliferation and enhance neuroplasticity both in vitro and in vivo. It is hypothesized that cita...Several studies have demonstrated that selective serotonin reuptake inhibitor antidepressants can promote neuronal cell proliferation and enhance neuroplasticity both in vitro and in vivo. It is hypothesized that citalopram, a selective serotonin reuptake inhibitor, can promote the neuronal differentiation of adult bone marrow mesenchymal stem cells. Citalopram strongly enhanced neuronal characteristics of the cells derived from bone marrow mesenchymal stem cells. The rate of cell death was decreased in citalopram-treated bone marrow mesenchymal stem cells than in control cells in neurobasal medium. In addition, the cumulative population doubling level of the citalopram-treated cells was signiifcantly increased compared to that of control cells. Also BrdU incorporation was elevated in citalopram-treated cells. These ifndings suggest that citalopram can improve the neuronal-like cell differentiation of bone marrow mesenchymal stem cells by increasing cell proliferation and survival while maintaining their neuronal characteristics.展开更多
In the present study, Schwann cells were isolated from the sciatic nerve of neonatal mice and purified using dispase and collagenase. Results showed that after the first round of purification with dispase, most of the...In the present study, Schwann cells were isolated from the sciatic nerve of neonatal mice and purified using dispase and collagenase. Results showed that after the first round of purification with dispase, most of the Schwann cells appeared round in shape and floated in culture solution after 15 minutes. In addition, cell yield and cell purity were higher when compared to the collagenase group. After the second round of purification, the final cell yield for the dispase group was higher than that for the collagenase group, but no significant difference was found in cell purity. Moreover, similar results in cell quantity and purity were observed in adult Sprague-Dawley rats. These findings indicate that purification with dispase can result in the rapid isolation of Schwann cells with a high yield and purity.展开更多
Focal adhesions are polyproteins linked to extracellular matrix and cytoskeleton,which play an important role in the process of transforming force signals into intracellular chemical signals and subsequently triggerin...Focal adhesions are polyproteins linked to extracellular matrix and cytoskeleton,which play an important role in the process of transforming force signals into intracellular chemical signals and subsequently triggering related physiological or pathological reactions.The cytoskeleton is a network of protein fibers in the cytoplasm,which is composed of microfilaments,microtubules,intermediate filaments,and cross-linked proteins.It is a very important structure for cells to maintain their basic morphology.This review summarizes the process of fluid shear stress transduction mediated by focal adhesion and the key role of the cytoskeleton in this process,which focuses on the focal adhesion and cytoskeleton systems.The important proteins involved in signal transduction in focal adhesion are introduced emphatically.The relationship between focal adhesion and mechanical transduction pathways are discussed.In this review,we discuss the relationship between fluid shear stress and associated diseases such as atherosclerosis,as well as its role in clinical research and drug development.展开更多
Theoretically, mesenchymal stem cells (MSCs) are very promising as adjuvanttherapy to alleviate coronavirus disease 2019 (COVID-19)-associated acute lunginjury and cytokine storm. Several published studies, which used...Theoretically, mesenchymal stem cells (MSCs) are very promising as adjuvanttherapy to alleviate coronavirus disease 2019 (COVID-19)-associated acute lunginjury and cytokine storm. Several published studies, which used MSCs toalleviate COVID-19-associated acute lung injury and cytokine storm, reportedpromising results. However, the evidence came from a case report, case series,and clinical trials with a limited number of participants. Therefore, more studiesare needed to get robust proof of MSC beneficial effects.展开更多
Myocardial infarction(MI)is a worldwide disease with high incidence and high fatality rate.In the past decade,a lot of research work based on the method of cardiac tissues engineering has received wide attention from ...Myocardial infarction(MI)is a worldwide disease with high incidence and high fatality rate.In the past decade,a lot of research work based on the method of cardiac tissues engineering has received wide attention from re-searchers and has been demonstrated to have important application prospects in the treatment of MI.To make engineered cardiac tissue(ECTs)simulate the characteristics of the natural myocardial microenvironment better,the unique electrophysiological characteristics of myocardial tissue should be considered.Therefore,conductive nanomaterials are adopted to construct ECTs to make up for the lack of traditional scaffold materials.In this arti-cle,the research progresses of conductive nanomaterials application in the field of cardiac tissue engineering are summarized,and two treatment strategies of cardiac patch construction and injectable materials for MI treatment are discussed respectively.Related research work provided reference for the study of cardiac tissue engineering based conductive nanomaterials.展开更多
AIM： To determine the safe dose of intravitreal clonidine（IVC）, a potential drug for neuroprotection and angiogenesis inhibition in rabbits. METHODS： A total of 28 rabbits were divided into four groups. Three grou...AIM： To determine the safe dose of intravitreal clonidine（IVC）, a potential drug for neuroprotection and angiogenesis inhibition in rabbits. METHODS： A total of 28 rabbits were divided into four groups. Three groups received IVC with concentrations of 15（Group A）, 25（Group B）, and 50（Group C） g/0.1 m L and the control group（Group D） received 0.1 m L balanced salt solution（BSS）. To investigate IVC safety, electroretinography（ERG） was performed at baseline, then at 1, 4 and 8 wk after injection. After last ERG, all rabbits were euthanized, their eyes were enucleated and subjected to routine histopathological evaluation, immunohistochemistry for glial fibrillary acidic protein（GFAP） and terminal deoxynucleotidyl transferase d UTP nick end labeling（TUNEL） test.RESULTS： Based on ERG, histopathology, GFAP and TUNEL assay findings, 15 g IVC was determined as the safe dose in rabbit eyes. While, the results of routine histopathology and TUNEL assay were unremarkable in all groups, toxic effects attributed to 25 and 50 g IVC were demonstrated by ERG and GFAP tests. CONCLUSION： Totally 15 g clonidine is determined as the safe dose for intravitreal injection in rabbits. Contribution of IVC in neuroprotection and inhibition of angiogenesis deserve more studies.展开更多
Four kinds of pure silicate ceramic particles,CaSiO3,Ca3SiO5,bredigite and akermanite were prepared and their bactericidal effects were systematically investigated.The phase compositions of these silicate ceramics wer...Four kinds of pure silicate ceramic particles,CaSiO3,Ca3SiO5,bredigite and akermanite were prepared and their bactericidal effects were systematically investigated.The phase compositions of these silicate ceramics were characterized by XRD.The ionic concentration measurement revealed that the Calcium （Ca） ion concentration were relatively higher in Ca3SiO5 and bredigite,and much lower in CaSiO3 and akermanite.Accordingly,the pH values of the four silicate ceramics extracts showed a positive correlation with the particle concentrations.Meanwhile,by decreasing the particle size,higher Ca ion concentrations can be achieved,leading to the increase of aqueous pH value as well.In summary,all of the four silicate ceramics tested in our study showed antibacterial effect in a dose-dependent manner.Generally,the order of their antibacterial activity against E.coli from strong to weak is Ca3SiO5,bredigite,CaSiO3 and akermanite.展开更多
Hydrogen evolution was detected in an artificial system composed of light-harvesting unit of purified photosystem I, catalyst of hydrogenase, methyl viologen and electron donor under radiation. Absorption spectral fea...Hydrogen evolution was detected in an artificial system composed of light-harvesting unit of purified photosystem I, catalyst of hydrogenase, methyl viologen and electron donor under radiation. Absorption spectral features confirmed that electron transfer from electron donors to proton was via a photoinduced reductive process of methyl viologen.展开更多
Stem cells have moved from lab to bedside, and many initial studies showed promising results. Therefore big companies are entering the business. However, most initial studies did not used controls to make sure of the ...Stem cells have moved from lab to bedside, and many initial studies showed promising results. Therefore big companies are entering the business. However, most initial studies did not used controls to make sure of the efficacy of stem cells. Many phase-1 studies showed safety of stem cell therapies, when precaution measures were adapted. However, efficacy needs to be proven by randomized controlled trials (RCT) to exclude placebo effects. Recently, various RCTs for various conditions have been done with various contradictory results. Therefore, a meta-analysis is very useful to know whether a stem cell therapy really work for a certain condition. As various centres used various type of stem cells, various dose, and route of application, as well as different outcome measures with various results for one certain condition, sometimes it is difficult to conduct a meta-analysis when there is high heterogeneity, which is like pooling “apples” with “oranges” and “avocado” that will lead to a misleading conclusion. In many cases, where the studies are highly heterogeneous, and the heterogeneity can’t be identified, then a descriptive systematic review is the best solution to take a conclusion which protocol is the best and valuable to be standardized. Formerly it was believed that stem cells that are given to patients work by differentiating into the needed cells, and thus replacing damaged cell. However, recent evidence showed that only a few stem cells homed to the desired area, while a large amount went to various areas that were remote from the damaged area. Even though they were trapped in remote areas, the stem cells still exerted beneficial effects by remote signalling and secretion of various beneficial factors. Therefore, there are attempts to produce stem cell secretomes/metabolites to replace the stem cells, as metabolites are easier to handle and transported compared to the cells themselves. In addition, various studies worked on substitute tissue/organs “ex vivo” to be transplanted to replace a damaged organ. There are various means to produce a tissue/an organ/organoid “ex vivo” (tissue engineering) by using various stem cells, scaffold, and soluble factors, in various vessels from static vessel to bioreactors, and “on chips”. Though these attempts are in the initial stage, but some translational animal studies have been done. A more usual use of these “ex vivo” developed tissues/organs/organoids is for drug testing, such as toxicity testing, and for studying the mechanism of certain diseases that is directed toward the development of a cure of the diseases. In conclusion, many stem cell therapies have entered RCTs, but no standardized and approved protocol has been established, while organoids are usually used for drug testing and studying the mechanism of certain diseases.展开更多
文摘Engineered cardiac constructs(ECC)aid in the progression of regenerative medicine,disease modeling and targeted drug delivery to adjust and aim the release of remedial combination as well as decrease the side effects of drugs.In this research,polycaprolactone/gold nanoparticles(PCL/GNPs)three-dimensional(3D)composite scaffolds were manufactured by 3D printing using the fused deposition modeling(FDM)method and then coated with gelatin/spironolactone(GEL/SPL).Scanning electron microscopy(SEM)and Fourier transform-infrared spectroscopy(FTIR–ATR)were applied to characterize the samples.Furthermore,drug release,biodegradation,behavior of the myoblasts(H9C2)cell line,and cytotoxicity of the 3D scaffolds were evaluated.The microstructural observation of the scaffolds reported interconnected pores with 150–300µm in diameter.The 3D scaffolds were degraded significantly after 28 days of immersion in stimulated body fluid(SBF),with the maximum rate of GEL-coated 3D scaffolds.SPL release from cross-linked GEL coating demonstrated the excess of drug release over time,and according to the control release systems,the drug delivery systems(DDS)went into balance after the 14th day.In addition,cell culture study showed that with the addition of GNPs,the proliferation of(H9C2)was enhanced,and with GEL/SPL coating the cell attachment and viability were improved significantly.These findings suggested that PCL/GNPs 3D scaffolds coated with GEL/SPL can be an appropriate choice for myocardial tissue engineering.
文摘Given the limited spontaneous repair that follows cartilage injury, demand is growing for tissue engi- neering approaches for cartilage regeneration. There are two major applications for tissue-engineered cartilage. One is in orthopedic surgery, in which the engineered cartilage is usually used to repair cartilage defects or loss in an articular joint or meniscus in order to restore the joint function. The other is for head and neck reconstruction, in which the engineered cartilage is usually applied to repair cartilage defects or loss in an auricle, trachea, nose, larynx, or eyelid. The challenges faced by the engineered car- tilage for one application are quite different from those faced by the engineered cartilage for the other application. As a result, the emphases of the engineering strategies to generate cartilage are usually quite different for each application. The statuses of preclinical animal investigations and of the clinical translation of engineered cartilage are also at different levels for each application. The aim of this review is to provide an opinion piece on the challenges, current developments, and future directions for cartilage engineering for both applications.
基金This project was supported by national high technology re search and development program of China ( 863 Program,2001AA216031), key technologies research and developmentprogram of Beijing (H020920050031).
文摘Tissue-engineering bone with porous β-tricalcium phosphate (β-TCP) ceramic and autologous bone marrow mesenchymal stem cells (MSC) was constructed and the effect of this composite on healing of segmental bone defects was investigated. 10-15 ml bone marrow aspirates were harvested from the iliac crest of sheep, and enriched for MSC by density gradient centrifugation over a Percoll cushion (1.073 g/ml). After cultured and proliferated, tissue-engineering bones were constructed with these cells seeded onto porous β-TCP, and then the constructs were implanted in 8 sheep left metatarsus defect (25 mm in length) as experimental group. Porous β-TCP only were implanted to bridge same size and position defects in 8 sheep as control group, and 25 mm segmental bone defects of left metatarsus were left empty in 4 sheep as blank group. Sheep were sacrificed on the 6th, 12th, and 24th week postoperatively and the implants samples were examined by radiograph, histology, and biomechanical test. The 4 sheep in blank group were sacrificed on the 24th week postoperatively. The results showed that new bone tissues were observed either radiographic or histologically at the defects of experimental group as early as 6th week postoperatively, but not in control group, and osteoid tissue, woven bone and lamellar bone occurred earlier than in control group in which the bone defects were repaired in “creep substitution” way, because of the new bone formed in direct manner without progression through a cartilaginous intermediate. At the 24th week, radiographs and biomechanical test revealed an almost complete repair of the defect of experimental group, only partly in control group. The bone defects in blank group were non-healing at the 24th week. It was concluded that engineering bones constructed with porous β-TCP and autologous MSC were capable of repairing segmental bone defects in sheep metatarsus beyond “creep substitution” way and making it healed earlier. Porous β-TCP being constituted with autologous MSC may be a good option in healing critical segmental bone defects in clinical practice and provide insight for future clinical repair of segmental defect.
基金supported by the Taishan Scholars Program of Shandong Province(tsqn202312344).
文摘Multiple sclerosis (MS) is characterized by chronic,slowly expanding lesions with the accumulation of myeloid cells,which lead to brain atrophy and progressive disability.The role of mitochondria,especially mitochondrial respiratory complexes and metabolites,in controlling myeloid immune responses,is well-documented but not fully understood in diseases of the central nervous system (CNS).The groundbreaking study by Prof.Peruzzotti-Jametti et al.[1],entitled"Mitochondrial complexⅠactivity in microglia sustains neuroinflammation"published in Nature,delves into the intricate dynamics between mitochondrial function within microglia and the perpetuation of chronic neuroinflammation,specifically in MS.The core point of their investigation is the hypothesis that mitochondrial complexⅠ(CI) activity,through a mechanism known as reverse electron transport (RET),generates reactive oxygen species (ROS) in microglia,thereby sustaining inflammatory response in the CNS.This increases ROS production from the mitochondria,which is thought to be a crucial factor in the maintenance of a pro-inflammatory state in the microglia,contributing to the pathology of MS and similar neuroinflammatory diseases.
基金Supported by Open Foundation of Shandong Key Laboratory of Oral Tissue Regeneration,No.SDDX202001Shandong Provincial Natural Science Foundation,No.ZR2021MH075Clinical Research Center of Shandong University,No.2020SDUCRCC006.
文摘BACKGROUND Human periodontal ligament stem cells(PDLSCs)regenerate oral tissue.In vitro expansion causes replicative senescence in stem cells.This causes intracellular reactive oxygen species(ROS)accumulation,which can impair stem cell function.Tissue engineering efficiency is reduced by exogenous ROS stimulation,which causes premature senescence under oxidative stress.Melatonin(MT),a powerful free radical scavenger,can delay PDLSCs senescence but may not maintain stemness under oxidative stress.This experiment examined the effects of hydrogen peroxide-induced oxidative stress on PDLSCs’apoptosis,senescence,and stemness.AIM To determine if MT can reverse the above effects along with the underlying molecular mechanisms involved.METHODS PDLSCs were isolated from human premolars and cultured in different conditions.Flow cytometry was used to characterize the cell surface markers of BACKGROUND Human periodontal ligament stem cells(PDLSCs)regenerate oral tissue.In vitro expansion causes replicative senescence in stem cells.This causes intracellular reactive oxygen species(ROS)accumulation,which can impair stem cell function.Tissue engineering efficiency is reduced by exogenous ROS stimulation,which causes premature senescence under oxidative stress.Melatonin(MT),a powerful free radical scavenger,can delay PDLSCs senescence but may not maintain stemness under oxidative stress.This experiment examined the effects of hydrogen peroxide-induced oxidative stress on PDLSCs’apoptosis,senescence,and stemness.AIM To determine if MT can reverse the above effects along with the underlying molecular mechanisms involved.METHODS PDLSCs were isolated from human premolars and cultured in different conditions.Flow cytometry was used to characterize the cell surface markers of differentiation,ROS,and senescence-associatedβ-galactosidase activity were assessed by various assays.Reverse transcription-polymerase chain reaction and western blot were used to measure the expression of genes and proteins related to stemness and senescence.RESULTS MT increases Yes-associated protein expression and maintains cell stemness in an induced inflammatory microenvironment,which may explain its therapeutic effects.We examined how MT affects PDLSCs aging and stemness and its biological mechanisms.CONCLUSION Our study reveals MT’s role in regulating oxidative stress in PDLSCs and Yes-associated protein-mediated activity,providing insights into cellular functions and new therapeutic targets for tissue regeneration.
基金supported by the National Natural Science Foundations of China(82273554,82073470)the Shandong Provincial Key R&D Program(ZR2019ZD36).
文摘The efficient clinical treatment of oral squamous cell carcinoma(OSCC)is still a challenge that demands the development of effective new drugs.Phenformin has been shown to produce more potent anti-tumor activities than metformin on different tumors,however,not much is known about the influence of phenformin on OSCC cells.We found that phenformin suppresses OSCC cell proliferation,and promotes OSCC cell autophagy and apoptosis to significantly inhibit OSCC cell growth both in vivo and in vitro.RNA-seq analysis revealed that autophagy pathways were the main targets of phenformin and identified two new targets DDIT4(DNA damage inducible transcript 4)and NIBAN1(niban apoptosis regulator 1).We found that phenformin significantly induces the expression of both DDIT4 and NIBAN1 to promote OSCC autophagy.Further,the enhanced expression of DDIT4 and NIBAN1 elicited by phenformin was not blocked by the knockdown of AMPK but was suppressed by the knockdown of transcription factor ATF4(activation transcription factor 4),which was induced by phenformin treatment in OSCC cells.Mechanistically,these results revealed that phenformin triggers endoplasmic reticulum(ER)stress to activate PERK(protein kinase R-like ER kinase),which phosphorylates the transitional initial factor eIF2,and the increased phosphorylation of eIF2 leads to the increased translation of ATF4.In summary,we discovered that phenformin induces its new targets DDIT4 and especially NIBAN1 to promote autophagic and apoptotic cell death to suppress OSCC cell growth.Our study supports the potential clinical utility of phenformin for OSCC treatment in the future.
基金supported by Jiangsu Province Key Research and Development Program(No.BE2022670)the National Key Research and Development Program of China(No.2023YFC2506300)+1 种基金Jiangsu Provincial Medical Key Discipline Cultivation Unit(No.JSDW202246)Nanjing Medical Science and Technology development Fund(ZKX22054).
文摘Endo-periodontal lesions (EPLs) involve both the periodontium and pulp tissue and have complicated etiologies and pathogenic mechanisms,including unique anatomical and microbiological characteristics and multiple contributing factors.This etiological complexity leads to difficulties in determining patient prognosis,posing great challenges in clinical practice.Furthermore,EPL-affected teeth require multidisciplinary therapy,including periodontal therapy,endodontic therapy and others,but there is still much debate about the appropriate timing of periodontal therapy and root canal therapy.By compiling the most recent findings on the etiology,pathogenesis,clinical characteristics,diagnosis,therapy,and prognosis of EPL-affected teeth,this consensus sought to support clinicians in making the best possible treatment decisions based on both biological and clinical evidence.
基金supported by National "863" High-tech R & D Program of China(No. 2007AA03Z317)the National Natural Science Foundation of China(No.31070870)+1 种基金"973" Program of the Ministry of Science and Technology of China (No.2007CB714502, 2007CB936000)Shanghai Municipal Committee of Science and Techology (No. 08520740300, 1052nm06100 and 09JC1416500)
文摘Objective： Procyanidins （PC） are widely available natural polyphenols. The present study is designed to investigate if PC can inhibit angiogenesis in lung adenocarcinoma xenografts through crosslinking vascular extracellular matrix （ECM） and preventing proteolysis by matrix metalloproteinases （MMPs）. Methods： Using the in vitro MMP-2 proteolysis and in vivo subcutaneous implantation models, we investigated if PC crosslinking inhibits MMP-mediated proteolysis. Using a cultured cell detachment assay, an in vitro angiogenesis assay, and a cell proliferation assay, we investigated if PC inhibits MMP-2-mediated endothelial cell detachment, angiogenesis, and cell proliferation, respectively. Using tumor xenografts, we evaluated if PC can inhibit growth of lung adenocarcinoma. Results： PC crosslink vascular ECM proteins, protecting them against proteolysis by MMPs in vitro and in vivo, protecting cultured human umbilical vein endothelial cells from detachment by MMP-2, and inhibiting in vitro angiogenesis. However, PC （0.75-100 μg/mL） did not inhibit vascular and tumor cells proliferation. PC injections （30 mg PC/kg bodyweight） in situ had anticancer effects on xenografts of lung adenocarcinoma, most likely by inhibiting angiogenesis during ECM proteolysis by MMPs. Conclusion： The results suggest that PC may be important MMP inhibitors that can be used as therapeutic anticancer agents.
基金supported by the National High Technology Research and Development Program of China (No 2006AA02A105 to CW)the National Nature Science Foundation of China (No 30530220)Beijing Nature Science Foundation of China (No 7062053)
文摘Embryonic stem （ES） cells have the potential to develop into any type of tissue and are considered as a promising source of seeding cells for tissue engineering and transplantation therapy.The main catalyst for ES cells differentiation is the growth into embryoid bodies （EBs）,which are utilized widely as the trigger of in vitro differentiation.In this study,a novel method for generating EBs from mouse ES cells through culture in collagen/Matrigel scaffolds was successfully established.When single ES cells were seeded in three dimensional collagen/Matrigel scaffolds,they grew into aggregates gradually and formed simple EBs with circular structures.After 7 days＇ culture,they formed into cystic EBs that would eventually differentiate into the three embryonic germ layers.Evaluation of the EBs in terms of morphology and potential to differentiate indicated that they were typical in structure and could generate various cell types;they were also able to form into tissue-like structures.Moreover,with introduction of ascorbic acid,ES cells differentiated into cardiomyocytes efficiently and started contracting synchronously at day 19.The results demonstrated that collagen/Matrigel scaffolds supported EBs formation and their subsequent differentiation in a single three dimensional environment.
文摘Aim： To identify proteins induced by androgen in Sertoli cells during spermatogenesis. Methods： We analyzed protein profiles in TM4 Sertoli cells treated with dihydrotestosterone （DHT） using surface enhanced laser desorption ionization time-of-flight mass spectrometry （SELDI-TOF-MS）. Results： We found increases in the expression of a 5.0-kDa protein at 15 min, an 11.3-kDa protein at 24 h and 4.3 kDa, 5.7 kDa, 5.8 kDa, 9.95 kDa and 9.98 kDa proteins at 48 h after the treatment. In contrast, the expression of 6.3 kDa and 8.6 kDa proteins decreased at 30 min, and 4.9 kDa, 5.0 kDa, 12.4 kDa and 19.8 kDa proteins at 48 h after the treatment. The ll.3-kDa protein was identified as macrophage migration inhibitory factor （MIF） known to having various functions. The 9.98-kDa protein was identified as calgizzarin related to calcium channels. The timing of their expression suggests that MIF and calgizzarin are involved in late regulation of spermatogenesis in Sertoli cells by androgen. Conclusion： MIF and calgizzarin are two important androgen-responsive proteins produced by Sertoli cells and they might play a role in regulating spermatogenesis.
基金funded by the Research Center for Science and Technology in Medicine(RCSTiM),Tehran University of Medical Sciences,Tehran(TUMS),Tehran,Iran
文摘Several studies have demonstrated that selective serotonin reuptake inhibitor antidepressants can promote neuronal cell proliferation and enhance neuroplasticity both in vitro and in vivo. It is hypothesized that citalopram, a selective serotonin reuptake inhibitor, can promote the neuronal differentiation of adult bone marrow mesenchymal stem cells. Citalopram strongly enhanced neuronal characteristics of the cells derived from bone marrow mesenchymal stem cells. The rate of cell death was decreased in citalopram-treated bone marrow mesenchymal stem cells than in control cells in neurobasal medium. In addition, the cumulative population doubling level of the citalopram-treated cells was signiifcantly increased compared to that of control cells. Also BrdU incorporation was elevated in citalopram-treated cells. These ifndings suggest that citalopram can improve the neuronal-like cell differentiation of bone marrow mesenchymal stem cells by increasing cell proliferation and survival while maintaining their neuronal characteristics.
基金supported by the National Natural Science Foundation of China, No. 30872630, 81000522 and 30973050Shanghai Shenkang Laboratory Funding, No. SHDC12007706
文摘In the present study, Schwann cells were isolated from the sciatic nerve of neonatal mice and purified using dispase and collagenase. Results showed that after the first round of purification with dispase, most of the Schwann cells appeared round in shape and floated in culture solution after 15 minutes. In addition, cell yield and cell purity were higher when compared to the collagenase group. After the second round of purification, the final cell yield for the dispase group was higher than that for the collagenase group, but no significant difference was found in cell purity. Moreover, similar results in cell quantity and purity were observed in adult Sprague-Dawley rats. These findings indicate that purification with dispase can result in the rapid isolation of Schwann cells with a high yield and purity.
基金the Innovative Research Team of Taizhou Polytechnic College(No.TZYTD-16-4)Natural Science Research General Project of Jiangsu Higher Education Institutions(No.18KJD350002)the Doctoral Research Foundation of Taizhou Polytechnic College(No.1322819004).
文摘Focal adhesions are polyproteins linked to extracellular matrix and cytoskeleton,which play an important role in the process of transforming force signals into intracellular chemical signals and subsequently triggering related physiological or pathological reactions.The cytoskeleton is a network of protein fibers in the cytoplasm,which is composed of microfilaments,microtubules,intermediate filaments,and cross-linked proteins.It is a very important structure for cells to maintain their basic morphology.This review summarizes the process of fluid shear stress transduction mediated by focal adhesion and the key role of the cytoskeleton in this process,which focuses on the focal adhesion and cytoskeleton systems.The important proteins involved in signal transduction in focal adhesion are introduced emphatically.The relationship between focal adhesion and mechanical transduction pathways are discussed.In this review,we discuss the relationship between fluid shear stress and associated diseases such as atherosclerosis,as well as its role in clinical research and drug development.
文摘Theoretically, mesenchymal stem cells (MSCs) are very promising as adjuvanttherapy to alleviate coronavirus disease 2019 (COVID-19)-associated acute lunginjury and cytokine storm. Several published studies, which used MSCs toalleviate COVID-19-associated acute lung injury and cytokine storm, reportedpromising results. However, the evidence came from a case report, case series,and clinical trials with a limited number of participants. Therefore, more studiesare needed to get robust proof of MSC beneficial effects.
基金supported by the Key Program of the National Key Research and Development Program of China (No.2017YFA0106100,No.2016YFY1101303)Key Program of National Natural Science Foundation of China (No.31830030)Joint Funds for National Natural Science Foundation of China (No.U1601221).
文摘Myocardial infarction(MI)is a worldwide disease with high incidence and high fatality rate.In the past decade,a lot of research work based on the method of cardiac tissues engineering has received wide attention from re-searchers and has been demonstrated to have important application prospects in the treatment of MI.To make engineered cardiac tissue(ECTs)simulate the characteristics of the natural myocardial microenvironment better,the unique electrophysiological characteristics of myocardial tissue should be considered.Therefore,conductive nanomaterials are adopted to construct ECTs to make up for the lack of traditional scaffold materials.In this arti-cle,the research progresses of conductive nanomaterials application in the field of cardiac tissue engineering are summarized,and two treatment strategies of cardiac patch construction and injectable materials for MI treatment are discussed respectively.Related research work provided reference for the study of cardiac tissue engineering based conductive nanomaterials.
文摘AIM： To determine the safe dose of intravitreal clonidine（IVC）, a potential drug for neuroprotection and angiogenesis inhibition in rabbits. METHODS： A total of 28 rabbits were divided into four groups. Three groups received IVC with concentrations of 15（Group A）, 25（Group B）, and 50（Group C） g/0.1 m L and the control group（Group D） received 0.1 m L balanced salt solution（BSS）. To investigate IVC safety, electroretinography（ERG） was performed at baseline, then at 1, 4 and 8 wk after injection. After last ERG, all rabbits were euthanized, their eyes were enucleated and subjected to routine histopathological evaluation, immunohistochemistry for glial fibrillary acidic protein（GFAP） and terminal deoxynucleotidyl transferase d UTP nick end labeling（TUNEL） test.RESULTS： Based on ERG, histopathology, GFAP and TUNEL assay findings, 15 g IVC was determined as the safe dose in rabbit eyes. While, the results of routine histopathology and TUNEL assay were unremarkable in all groups, toxic effects attributed to 25 and 50 g IVC were demonstrated by ERG and GFAP tests. CONCLUSION： Totally 15 g clonidine is determined as the safe dose for intravitreal injection in rabbits. Contribution of IVC in neuroprotection and inhibition of angiogenesis deserve more studies.
基金Funded by the Natural Science Foundation of Hubei Province(No.2009CHB006)the China Postdoctoal Science Foundation(No.20060400679)Funds of the Chinese Academy of Key Topics in Innovation Engineering(No.KGCX2-YW-207)
文摘Four kinds of pure silicate ceramic particles,CaSiO3,Ca3SiO5,bredigite and akermanite were prepared and their bactericidal effects were systematically investigated.The phase compositions of these silicate ceramics were characterized by XRD.The ionic concentration measurement revealed that the Calcium （Ca） ion concentration were relatively higher in Ca3SiO5 and bredigite,and much lower in CaSiO3 and akermanite.Accordingly,the pH values of the four silicate ceramics extracts showed a positive correlation with the particle concentrations.Meanwhile,by decreasing the particle size,higher Ca ion concentrations can be achieved,leading to the increase of aqueous pH value as well.In summary,all of the four silicate ceramics tested in our study showed antibacterial effect in a dose-dependent manner.Generally,the order of their antibacterial activity against E.coli from strong to weak is Ca3SiO5,bredigite,CaSiO3 and akermanite.
基金the NEDO＇s International Joint Research Grant Program and the National Science Foundation of China （No. 20573025） for the financial supports.
文摘Hydrogen evolution was detected in an artificial system composed of light-harvesting unit of purified photosystem I, catalyst of hydrogenase, methyl viologen and electron donor under radiation. Absorption spectral features confirmed that electron transfer from electron donors to proton was via a photoinduced reductive process of methyl viologen.
文摘Stem cells have moved from lab to bedside, and many initial studies showed promising results. Therefore big companies are entering the business. However, most initial studies did not used controls to make sure of the efficacy of stem cells. Many phase-1 studies showed safety of stem cell therapies, when precaution measures were adapted. However, efficacy needs to be proven by randomized controlled trials (RCT) to exclude placebo effects. Recently, various RCTs for various conditions have been done with various contradictory results. Therefore, a meta-analysis is very useful to know whether a stem cell therapy really work for a certain condition. As various centres used various type of stem cells, various dose, and route of application, as well as different outcome measures with various results for one certain condition, sometimes it is difficult to conduct a meta-analysis when there is high heterogeneity, which is like pooling “apples” with “oranges” and “avocado” that will lead to a misleading conclusion. In many cases, where the studies are highly heterogeneous, and the heterogeneity can’t be identified, then a descriptive systematic review is the best solution to take a conclusion which protocol is the best and valuable to be standardized. Formerly it was believed that stem cells that are given to patients work by differentiating into the needed cells, and thus replacing damaged cell. However, recent evidence showed that only a few stem cells homed to the desired area, while a large amount went to various areas that were remote from the damaged area. Even though they were trapped in remote areas, the stem cells still exerted beneficial effects by remote signalling and secretion of various beneficial factors. Therefore, there are attempts to produce stem cell secretomes/metabolites to replace the stem cells, as metabolites are easier to handle and transported compared to the cells themselves. In addition, various studies worked on substitute tissue/organs “ex vivo” to be transplanted to replace a damaged organ. There are various means to produce a tissue/an organ/organoid “ex vivo” (tissue engineering) by using various stem cells, scaffold, and soluble factors, in various vessels from static vessel to bioreactors, and “on chips”. Though these attempts are in the initial stage, but some translational animal studies have been done. A more usual use of these “ex vivo” developed tissues/organs/organoids is for drug testing, such as toxicity testing, and for studying the mechanism of certain diseases that is directed toward the development of a cure of the diseases. In conclusion, many stem cell therapies have entered RCTs, but no standardized and approved protocol has been established, while organoids are usually used for drug testing and studying the mechanism of certain diseases.
