Spores and pollen,as ubiquitous organisms found in nature,possess a remarkable core-shell structure and intricate surface morphology.These tiny particles are notable for their dimensional uniformity,sustainable utiliz...Spores and pollen,as ubiquitous organisms found in nature,possess a remarkable core-shell structure and intricate surface morphology.These tiny particles are notable for their dimensional uniformity,sustainable utilization,environmental friendliness,porosity,amphiphilicity,and strong adhesive properties.In addition,they display excellent biocompatibility and biodegradability,which significantly enhances the stability and targeting of drugs within the body.Spores and pollen can be extracted using methods such as acidic solutions,alkaline solutions,or enzyme treatments to obtain sporopollenin,which is an extremely resilient and chemically inert complex biopolymer.The sporopollenin extracted through this process removes the original bioactive substances,such as cell nuclei,enzymes,and DNA,providing greater drug loading capacity and containing no potential allergens or immunogens,thus further enhancing its drug loading capacity and improving safety in therapeutic applications.Due to these beneficial attributes,spores,pollen and sporopollenin have gained widespread use in a variety of drug delivery systems,such as targeted delivery,sustained drug delivery,toxicity mitigation,flavor masking,vaccine delivery,delivery of labile substances,and other applications.This review introduces the types of natural spores and pollen commonly used in drug delivery systems,including their main components,common effects,and uses in drug delivery systems,and so on.It subsequently summarizes novel optimization methods in their processing,such as physical treatment,surface modification,and chemical modification,which enable higher drug loading efficiency,stability,and targeting,among other benefits.Additionally,this paper reviews the research progress and applications of natural spores,pollen,and sporopollenin in drug delivery systems,while also touching on some innovative research content,such as novel nanomotor microcarriers developed based on pollen.Based on these research findings,we further elaborate on the advantages of spores,pollen,and sporopollenin in drug delivery systems.For example,they have high stability and drug loading capacity,good adhesion,excellent targeting,and are easy to modify functionally.Currently,they show promising prospects in the fields of targeted drug delivery,sustained-release drug delivery,as well as the delivery of drugs that are effective but slightly toxic,and are often used in research on the treatment of diseases such as cancer and inflammation.We have also highlighted the challenges they face in various applications and identified some issues that need to be addressed,including difficulties in largescale production,the need to improve extraction and purification processes,and the existence of a low but still noteworthy risk of allergies,in order to fully leverage their potential in drug delivery applications.According to current research,although spores,pollen,and sporopollenin face some unresolved issues in clinical drug delivery,they still have great potential overall and are expected to become a new generation of green drug delivery platforms.In the future,further research into their unique physical and chemical properties and structural characteristics will help develop more efficient and stable drug delivery systems to meet diverse treatment needs.We believe that continued exploration of natural spores,pollen,and sporopollenin will drive this emerging field to achieve continuous breakthroughs and progress,ultimately making an important contribution to the cause of human health.展开更多
Numerous studies have shown that cell replacement therapy can replenish lost cells and rebuild neural circuitry in animal models of Parkinson’s disease.Transplantation of midbrain dopaminergic progenitor cells is a p...Numerous studies have shown that cell replacement therapy can replenish lost cells and rebuild neural circuitry in animal models of Parkinson’s disease.Transplantation of midbrain dopaminergic progenitor cells is a promising treatment for Parkinson’s disease.However,transplanted cells can be injured by mechanical damage during handling and by changes in the transplantation niche.Here,we developed a one-step biomanufacturing platform that uses small-aperture gelatin microcarriers to produce beads carrying midbrain dopaminergic progenitor cells.These beads allow midbrain dopaminergic progenitor cell differentiation and cryopreservation without digestion,effectively maintaining axonal integrity in vitro.Importantly,midbrain dopaminergic progenitor cell bead grafts showed increased survival and only mild immunoreactivity in vivo compared with suspended midbrain dopaminergic progenitor cell grafts.Overall,our findings show that these midbrain dopaminergic progenitor cell beads enhance the effectiveness of neuronal cell transplantation.展开更多
The development of large-scale cell cultivation and non-invasive cell harvesting is highly desired in various fields,including biological regeneration and pharmaceutical research.When using traditional microcarriers f...The development of large-scale cell cultivation and non-invasive cell harvesting is highly desired in various fields,including biological regeneration and pharmaceutical research.When using traditional microcarriers for cell culture,trypsinization is often necessary during cell collection,leading to partial cells damage.In this work,we developed a thermoresponsive glass microcarrier modified with poly(γ-propargyl-L-glutamate)(PPLG)and poly(N-isopropylacrylamide)(PNIPAM).We utilized these microcarriers for three-dimensional cell culture and enzyme-free cell harvesting,and the results indicated that the prepared microcarriers exhibited excellent non-invasive cell culture performance.展开更多
AIM To develop a culture mode providingdurable biomaterials with high yields andactivities used in bioartificial liver.METHODS Hepatocytes were isolated from awhole pig liver by Seglen’s method of orthotopicperfusion...AIM To develop a culture mode providingdurable biomaterials with high yields andactivities used in bioartificial liver.METHODS Hepatocytes were isolated from awhole pig liver by Seglen’s method of orthotopicperfusion with collagenase.In culture onmicrocarriers,primary porcine hepatocyteswere inoculated at a concentration of 5×10~7/mLinto the static culture systems containing 2 g/LCytodex-3,then supplemented with 100 mL/Lfetal calf serum(FCS)or 100 mL/L porcineportal vein serum(PPVS)respectively.Inspheroidal aggregate culture hepatocytes wereinoculated into 100 mL siliconized flasks at aconcentration of 5.0×10~6/mL.RESULTS In culture on microcarriershepatocytes tended to aggregate on Cytodex-3obviously after being inoculated.Typical multi-cellular aggregated spheroids could be found inthe two systems 24 h-48 h after hepatocyteswere cultured.The morphological charact-eristics and synthetic functions were maintainedfor 5 wk in FCS culture system and 8 wk in PPVSculture system.In spheroidal aggregate cultureabout 80%-90% isolated hepatocytes becameaggregated spheroids 24h after cultured insuspension and mean diameter of the spheroidswas 100μm.The relationship among thehepatocytes resembled that in the liver in vivo.Synthetic functions of albumin and urea of the spheroids were twice those of hepatocytescultured on monolayers.CONCLUSION As high-yields and high-activitymodes of culture on microcarriers or inspheroidal aggregate culture with portal veinserum are promising to provide biomaterials forbioartificial liver(BAL)efficiently.展开更多
BACKGROUND: The bioartificial liver (BAL) is considered a possible alternative method for treating liver failure. The core of the BAL system is culturing liver cells in vitro with high density and activity. Microcarri...BACKGROUND: The bioartificial liver (BAL) is considered a possible alternative method for treating liver failure. The core of the BAL system is culturing liver cells in vitro with high density and activity. Microcarrier culture is a mode of high-density culture. We set out to prepare a novel porous microcarrier to improve the activity of liver cells in vitro. METHODS: Chitosan was used to prepare a novel porous spherical microcarrier with interconnected structure. The chitosan porous microcarriers (CPMs) were modified with gelatin to improve their biocompatibility. CPMs were co-cultured with liver cells, HL-7702 (L-02), to evaluate their effect on cell culture. RESULTS: The average size of the CPMs was about 400 μm in diameter and their apertures were less than 30 μm. The pores of the microcarrier were interconnected. After fixation by sodium tripolyphosphate, the structure of the first freeze-dried CPMs was stable. To further improve the biocompatibility, the surface of CPMs was modified with gelatin through chemical crosslinking (GM-CPMs). Comparing the proliferation curves of L-02 cells cultured on simple CPMs, GM-CPMs and tissue culture polystyrene (TCPS, a mode of planar cell culture), the proliferation rates were similar in the first 5 days and the cells proliferated until day 8 in culture with microcarriers. The OD value of liver cells cultured on GM-CPMs was 1.97-fold higher than that on TCPS culture at day 8. Levels of urea and albumin in supernatants of cells cultured on GM-CPMs increased steadily for 8 days, and were clearly higher than those of cells cultured on TCPS (P<0.05).CONCLUSIONS: The novel CPMs were promising microcarriers for hepatocyte culture and the GM-CPM seemed better. Porous microcarrier culture was beneficial for hepatocyte function and activity.展开更多
Bacterial infection causes wound inflammation and makes angiogenesis difficult.It is urgent to develop effectively antibacterial and pro-vascularizing dressings for wound healing.The hydrogel is developed with pH-resp...Bacterial infection causes wound inflammation and makes angiogenesis difficult.It is urgent to develop effectively antibacterial and pro-vascularizing dressings for wound healing.The hydrogel is developed with pH-responsive drug-releasing microcarriers which were loaded with vascular endothelial growth factor(VEGF)that promotes angiogenesis and actively respond to wound pH for control and prolong VEGF release.The surfaces of the microcarriers were coated with polydopamine which can reduce the silver nanoparticles(AgNPs)in situ,and dynamically crosslink with the polyacrylamide,which forms a stable slow-release system with different release behavior for the VEGF and AgNPs.The hydrogel inhib-ited bacterial formation and accelerated wound healing.With the hydrogel dressing,83.3%±4.29%of the wound heals at day 7,which is 40.9%±8.5%higher than the non-treatment group in defect infected model.The antibacterial properties of hydrogel down-regulate early inflammation-related cytokines,and the release of VEGF in the middle and late phases of wound healing in response to pH changes pro-motes angiogenesis and up-regulate the expression of angiogenesis-associated cytokine.The sequential release of antibacterial agents and pro-vascularizing agents in response to the change in wound microen-vironmental cues facilitate temporally controlled therapy that suites the need of different wound healing phases.Collectively,the hydrogel loaded with multifunctional microcarriers that enable controlled release of AgNPs and VEGF is an effective system for treating infected wounds.展开更多
An rCHO cell line expressing recombinant human prourokinase （pro-UK） at the level of 5μg/ 10^6cells/d was cultivated on Cytopore cellulose porous microcarriers in a 7.5L Biostat CT stirred tank reactor. A periodic ...An rCHO cell line expressing recombinant human prourokinase （pro-UK） at the level of 5μg/ 10^6cells/d was cultivated on Cytopore cellulose porous microcarriers in a 7.5L Biostat CT stirred tank reactor. A periodic pressure oscillation of 0.04 MPa and 0.04 Hz was adopted to introduce a physical stimulus on the rCHO cells and to improve mass transfer characteristic between cells and medium in the process of porous microcarrier CHO cell culture. Compared to constant pressure culture, the oscillation culture didn＇t influence specific cell growth rate significantly, but could enhance the pro-UK specific production by 10% - 40%, and reduce production of lactate by 10% - 30%. In the perfusion culture of recombinant CHO cell with serum-free medium for 67 days, cell density could reach 2.64×10^7/ml, the maximal prourokinase concentration in harvested supernatant was about 118mg/L, a total of 21.1 grams of prourokinase was produced in 313 liters of supernatant. In conclusion, the perfusion cell culture with periodic pressure oscillation can enhance the production of recombinant protein and increase the reactor specific productivity.展开更多
CD-1, a genetically-engineered CHO cell line, was cultivated with a Biosilon microcarrier culture system.We successfully cultivated CD-1 cells to a very high density (over1×107cells/ml). Prourokinase was stably s...CD-1, a genetically-engineered CHO cell line, was cultivated with a Biosilon microcarrier culture system.We successfully cultivated CD-1 cells to a very high density (over1×107cells/ml). Prourokinase was stably secreted at about 180 IU/ 1e6 cells/24 h. Experiments showed that CD-1 cells growing on Biosilon microcarriers were able to spontaneously release from the microcarriers, then reatthch and proliferate on fresh microcarriers. This makes it very easy to scale up preduction. The microcarriers could be reused several times without affecting adhesion. proliferation and prourokinase secretion. With CMPECC membrane radial flow chromatography and MPG chromatography, the prourokinase in conditioned medium could be purified to a specific activity of 1×105 IU/mg of protein. The purification factor was about 600 fold, and approxiamately 90 % of the biological activity was recovered.展开更多
Genetically-engineered CHO cell lines, rβ- 13 and CLF-8B2, were cultivated with the MC- 1 microcarrier culture system. The cell density could be enhanced by increasing the concentration of microcarrier. At a microcar...Genetically-engineered CHO cell lines, rβ- 13 and CLF-8B2, were cultivated with the MC- 1 microcarrier culture system. The cell density could be enhanced by increasing the concentration of microcarrier. At a microcarrier concentration of 10 mg/ml. the cell density could reach 4 to 5 × 106 cells/ml. It was shown that these cell lines would spontaneously release from the microcarrier to attach to and proliferate on fresh microcarriers. We were thus able to scale up cultivation using a simple method. i. e. by adding fresh microcarriers and medium directly into the culture system to about 2, 4 or 8 times the original volume. Using a perfusion culture system. we have successfully cultivated CLF-8B2 cells in a 2 L bioreactor for several weeks at medium perfusion rates of 0. 5 to 3working volumes. Prourokinase was stably secreted.展开更多
objective: To cultivate human liver cell line (CL-1) on microcarriers and study the synthetic and transformational function of this culture system. Methods:CL-1 were cultivated on Cytodex-3 microcarriers. The cell gro...objective: To cultivate human liver cell line (CL-1) on microcarriers and study the synthetic and transformational function of this culture system. Methods:CL-1 were cultivated on Cytodex-3 microcarriers. The cell growth was kinetically inspected with light microscope and scanning electronic microscope on the lst, 3rd, 5th, 7th, 9th day, and the amount of diazepam transformation and albumin synthesis were deter mined at the same time. Results:On 7th day after inoculating, the CL-1 cell density could reach 2. 16 ×106/ ml ; the amount of diazepam trans formation was 619 μg and albumin synthesis 78. 23 μg. Conclusion:CL-1 can be cultivated to a high density on microcarriers and has hepatic specific biotransformation and biosynthesis functions. So the culture system may be further studied for being used as the biomaterial of bioartificial liver.展开更多
The fact of microcarrier (MC) culture introduces new possibilities and makes possible the practical high-yield culture of anchorage-dependent cells has generated a considerable focus in this study. The objective of th...The fact of microcarrier (MC) culture introduces new possibilities and makes possible the practical high-yield culture of anchorage-dependent cells has generated a considerable focus in this study. The objective of this research was to study the comparison of Vero cell growth on different types of commercial microcarriers;Cytodex-1, Cytodex-3, Hil-lex? II and Plastic Plus in spinner vessel and two liters bioreactor cultured for 96 hours. Biological performance of the microcarrier in RPMI media showed the preference of Vero cell grew on Cytodex 3 microcarriers with highest maximum viable cell number (2.4 × 105 cells/ml) followed by Cytodex 1, Hillex and Plustic Plus. Vero cell on Cyto-dex-3 data in spinner flask was compared in bioreactor and result showed higher viable cell number in biorector. Thus, this dextran-crosslink gelatin microcarrier (Cytodex 3) provided the best surface for cell attachment and fast proliferation. At the end of this cell growth improvement will be used for virus transfection producing a vaccine in bioreactor.展开更多
The upstream process was carried out in an animal component-free medium on Cytodex 1 microcarriers. Recombinant trypsin is a non-animal derived protease used as an alternative to animal-derived trypsin. To inactivate ...The upstream process was carried out in an animal component-free medium on Cytodex 1 microcarriers. Recombinant trypsin is a non-animal derived protease used as an alternative to animal-derived trypsin. To inactivate recombinant trypsin, a soybean trypsin inhibitor (STI) should be added to the medium. A protocol was first tested in T-flasks and then passaged to 500 mL and 3 L spinner flasks. Cell detachment was completed in 10 - 12 min, and 0.4 g/L STI was added to a 3L spinner, and cells were transferred into a 30 L stirred tank bioreactor. On day 5, the cell density had reached its maximum (around 1.8 × 106 cells/mL). At an MOI of 0.3 with serum-free medium conditions, cell infection yielded a maximal rabies virus titer of 1.82 × 10<sup>7</sup> FFU/mL at 5 days. All cell culture conditions and virus growth kinetics in serum-free media were investigated. In conclusion, Vero cells were grown on Cytodex 1 with serum-free media and a high amount of rabies virus was obtained. A mouse challenge was used to determine the immune response to an inactivated rabies virus vaccine candidate. Also, we evaluated inactive rabies vaccine candidate safety, and immunogenicity in mice, sheep, horses, and cattle. We found that no horses, sheep, or cattle who were given vaccine IM at 3.2 IU/dose exhibited any clinical sign of disease and all developed high VNA titers (up to 10.03 IU/mL) by 3 - 4 WPI. After the accelerated stability studies, the lyophilized inactivated rabies vaccine candidate showed enough antigenic potency (2.6 IU/mL) in the mouse challenge test. Also, 18-month long-term stability studies showed enough immune response (1.93 IU/mL) on day 14. The activity of the vaccine candidate showed a good immune response and safety criteria that meet WHO requirements. This is the first pilot-scale mammalian cell-based viral rabies vaccine production study in Türkiye that used microcarriers.展开更多
The fructose modified chitosan microcarries (CMs) were prepared by the reaction of glutaraldehyde with fructose-modified chitosan. Various factors that influence the preparation were studied and the reaction condition...The fructose modified chitosan microcarries (CMs) were prepared by the reaction of glutaraldehyde with fructose-modified chitosan. Various factors that influence the preparation were studied and the reaction conditions were optimized. Morphology of rat hepatocytes cultured on CMs was observed using phase contrast microscope and scanning electron microscope, and the metabolic activities were measured. Rat hepatocytes cultured on CMs retained the spherical shape as they have in vivo and had high metabolic activities. Fructose can enhance the metabolic activity of hepatocytes and the modified CMs are promising scaffold for hepatocytes attachment.展开更多
Using polyvinyl alcohol (PVA) as raw material and vacuum pump oil as oil phase medium, PVA-based microcarriers were prepared by suspension method. The diameters of the beads were 100-180μm. LO2 cells were cultured on...Using polyvinyl alcohol (PVA) as raw material and vacuum pump oil as oil phase medium, PVA-based microcarriers were prepared by suspension method. The diameters of the beads were 100-180μm. LO2 cells were cultured on PVA-based microcarriers and cytodexIII microcarriers. Morphology, attachment and growth rate of LO2 cells were studied.展开更多
Long-term exposure to ultraviolet radiation compromises skin structural integrity and results in disruption of normal physiological functions.Stem cells have gained attention in anti-photoaging,while controlling the t...Long-term exposure to ultraviolet radiation compromises skin structural integrity and results in disruption of normal physiological functions.Stem cells have gained attention in anti-photoaging,while controlling the tissue mechanical microenvironment of cell delivery sites is crucial for regulating cell fate and achieving optimal therapeutic performances.Here,we introduce a mechanically regulated human recombinant collagen(RHC)microcarrier generated through microfluidics,which is capable of modulating stem cell differentiation to treat photoaged skin.By controlling the cross-linking parameters,the mechanical properties of microcarriers could precisely tuned to optimize the stem cell differentiation.The microcarriers are surface functionalized with fibronectin(Fn)-platelet derived growth factor-BB(PDGF-BB)to facilitate adipose derived mesenchymal stem cells(Ad-MSCs)loading.In in vivo experiments,subcutaneous injection of stem cell loaded RHC microcarriers significantly reduced skin wrinkles after ultraviolet-injury,effectively promoted collagen synthesis,and increased vascular density.These encouraging results indicate that the present mechanically regulated microcarriers have great potential to deliver stem cells and regulate their differentiation for anti-photoaging treatments.展开更多
Cartilage tissues possess an extremely limited capacity for self-repair,and current clinical surgical approaches for treating articular cartilage defects can only provide short-term relief. Despite significantadvances...Cartilage tissues possess an extremely limited capacity for self-repair,and current clinical surgical approaches for treating articular cartilage defects can only provide short-term relief. Despite significantadvances in the field of cartilage tissue engineering, avoiding secondary damage caused by invasive surgical procedures remains achallenge. In this study, injectable cartilage microtissues were developed through 3D culture of rat bone marrow mesenchymal stemcells (BMSCs) within porous gelatin microcarriers (GMs) and induceddifferentiation. These microtissues were then injected for thepurpose of treating cartilage defects in vivo, via a minimally invasiveapproach. GMs were found to be noncytotoxic and favorable for cellattachment, proliferation and migration evaluated with BMSCs. Moreover, cartilage microtissues with a considerable number of cells andabundant extracellular matrix components were obtained from BMSC-laden GMs after induction differentiation culture for 28days. Notably,ATDC5 cells were complementally tested to verify that the GMs were conducive to cell attachment, proliferation, migration and chondrogenicdifferentiation. The microtissues obtained from BMSC-laden GMs were then injected into articular cartilage defect areas in rats and achievedsuperior performance in alleviating inflammation and repairing cartilage. These findings suggest that the use of injectable cartilagemicrotissues in this study may hold promise for enhancing the long-term outcomes of cartilage defect treatments while minimizing the risk ofsecondary damage associated with traditional surgical techniques.展开更多
Microcarrier applications have made great advances in tissue engineering in recent years, which can load cells,drugs, and bioactive factors. These microcarriers can be minimally injected into the defect to help recons...Microcarrier applications have made great advances in tissue engineering in recent years, which can load cells,drugs, and bioactive factors. These microcarriers can be minimally injected into the defect to help reconstruct agood microenvironment for tissue repair. In order to achieve more ideal performance and face more complextissue damage, an increasing amount of effort has been focused on microcarriers that can actively respond toexternal stimuli. These microcarriers have the functions of directional movement, targeted enrichment, materialrelease control, and providing signals conducive to tissue repair. Given the high controllability and designabilityof magnetic and electroactive microcarriers, the research progress of these microcarriers is highlighted in thisreview. Their structure, function and applications, potential tissue repair mechanisms, and challenges are discussed.In summary, through the design with clinical translation ability, meaningful and comprehensiveexperimental characterization, and in-depth study and application of tissue repair mechanisms, stimuliresponsivemicrocarriers have great potential in tissue repair.展开更多
Conventional methods of stem cell therapy for tissue regeneration often face challenges,such as poor cell viability and integration posttransplantation.To address this,we proposed transplanting cells within synthetic ...Conventional methods of stem cell therapy for tissue regeneration often face challenges,such as poor cell viability and integration posttransplantation.To address this,we proposed transplanting cells within synthetic microenviron-ments that maintain viability,cell phenotype,support extracellular matrix(ECM)secretion,and promote differentiation to enhance the regeneration of damaged host tissue.This hypothesis was tested in dental tissue regeneration using dental pulp stem cell-laden microcarriers(MCs)mixed in a gelatin methacrylate(GelMA)hydrogel as a delivery system.The combination of MCs and GelMA exhibited similar physical properties and favorable biological properties compared to GelMA alone.Specifically,cell-laden MC mixed into GelMA enhanced cell proliferation and ECM secretion and maintained a normal phenotype.Notably,MC-modified GelMA amplified odontogenic differentiation,mineralization,and vascular endothelial growth factor release.Moreover,the storage of MC-modified GelMA showed no detrimental effects on its injection force,cell viability,and mineralization potential,which demonstrates that the composite hydrogel is a promising injectable vehicle for therapeutic stem cell delivery.This strategy may be broadly applied to various tissues and organ systems,in which the provision and instruction of a cell population to participate in regeneration may be clinically useful.展开更多
基金supported by a grant from The National Natural Science Foundation of China(32000997)。
文摘Spores and pollen,as ubiquitous organisms found in nature,possess a remarkable core-shell structure and intricate surface morphology.These tiny particles are notable for their dimensional uniformity,sustainable utilization,environmental friendliness,porosity,amphiphilicity,and strong adhesive properties.In addition,they display excellent biocompatibility and biodegradability,which significantly enhances the stability and targeting of drugs within the body.Spores and pollen can be extracted using methods such as acidic solutions,alkaline solutions,or enzyme treatments to obtain sporopollenin,which is an extremely resilient and chemically inert complex biopolymer.The sporopollenin extracted through this process removes the original bioactive substances,such as cell nuclei,enzymes,and DNA,providing greater drug loading capacity and containing no potential allergens or immunogens,thus further enhancing its drug loading capacity and improving safety in therapeutic applications.Due to these beneficial attributes,spores,pollen and sporopollenin have gained widespread use in a variety of drug delivery systems,such as targeted delivery,sustained drug delivery,toxicity mitigation,flavor masking,vaccine delivery,delivery of labile substances,and other applications.This review introduces the types of natural spores and pollen commonly used in drug delivery systems,including their main components,common effects,and uses in drug delivery systems,and so on.It subsequently summarizes novel optimization methods in their processing,such as physical treatment,surface modification,and chemical modification,which enable higher drug loading efficiency,stability,and targeting,among other benefits.Additionally,this paper reviews the research progress and applications of natural spores,pollen,and sporopollenin in drug delivery systems,while also touching on some innovative research content,such as novel nanomotor microcarriers developed based on pollen.Based on these research findings,we further elaborate on the advantages of spores,pollen,and sporopollenin in drug delivery systems.For example,they have high stability and drug loading capacity,good adhesion,excellent targeting,and are easy to modify functionally.Currently,they show promising prospects in the fields of targeted drug delivery,sustained-release drug delivery,as well as the delivery of drugs that are effective but slightly toxic,and are often used in research on the treatment of diseases such as cancer and inflammation.We have also highlighted the challenges they face in various applications and identified some issues that need to be addressed,including difficulties in largescale production,the need to improve extraction and purification processes,and the existence of a low but still noteworthy risk of allergies,in order to fully leverage their potential in drug delivery applications.According to current research,although spores,pollen,and sporopollenin face some unresolved issues in clinical drug delivery,they still have great potential overall and are expected to become a new generation of green drug delivery platforms.In the future,further research into their unique physical and chemical properties and structural characteristics will help develop more efficient and stable drug delivery systems to meet diverse treatment needs.We believe that continued exploration of natural spores,pollen,and sporopollenin will drive this emerging field to achieve continuous breakthroughs and progress,ultimately making an important contribution to the cause of human health.
基金supported by the National Key Research and Development Program of China,Nos.2017YFE0122900(to BH),2019YFA0110800(to WL),2019YFA0903802(to YW),2021YFA1101604(to LW),2018YFA0108502(to LF),and 2020YFA0804003(to JW)the National Natural Science Foundation of China,Nos.31621004(to WL,BH)and 31970821(to YW)+1 种基金CAS Project for Young Scientists in Basic Research,No.YSBR-041(to YW)Joint Funds of the National Natural Science Foundation of China,No.U21A20396(to BH)。
文摘Numerous studies have shown that cell replacement therapy can replenish lost cells and rebuild neural circuitry in animal models of Parkinson’s disease.Transplantation of midbrain dopaminergic progenitor cells is a promising treatment for Parkinson’s disease.However,transplanted cells can be injured by mechanical damage during handling and by changes in the transplantation niche.Here,we developed a one-step biomanufacturing platform that uses small-aperture gelatin microcarriers to produce beads carrying midbrain dopaminergic progenitor cells.These beads allow midbrain dopaminergic progenitor cell differentiation and cryopreservation without digestion,effectively maintaining axonal integrity in vitro.Importantly,midbrain dopaminergic progenitor cell bead grafts showed increased survival and only mild immunoreactivity in vivo compared with suspended midbrain dopaminergic progenitor cell grafts.Overall,our findings show that these midbrain dopaminergic progenitor cell beads enhance the effectiveness of neuronal cell transplantation.
基金supported by the name of National Key Research and Development Program of China(No.2021YFB3800900)the National Natural Science Foundation of China(Nos.51925305,51873208,1833010,51973217,52373161)Jilin Province Science and Technology Development Program(No.20200201075JC)。
文摘The development of large-scale cell cultivation and non-invasive cell harvesting is highly desired in various fields,including biological regeneration and pharmaceutical research.When using traditional microcarriers for cell culture,trypsinization is often necessary during cell collection,leading to partial cells damage.In this work,we developed a thermoresponsive glass microcarrier modified with poly(γ-propargyl-L-glutamate)(PPLG)and poly(N-isopropylacrylamide)(PNIPAM).We utilized these microcarriers for three-dimensional cell culture and enzyme-free cell harvesting,and the results indicated that the prepared microcarriers exhibited excellent non-invasive cell culture performance.
基金the National Natural Science Foundation of China,No.39570212
文摘AIM To develop a culture mode providingdurable biomaterials with high yields andactivities used in bioartificial liver.METHODS Hepatocytes were isolated from awhole pig liver by Seglen’s method of orthotopicperfusion with collagenase.In culture onmicrocarriers,primary porcine hepatocyteswere inoculated at a concentration of 5×10~7/mLinto the static culture systems containing 2 g/LCytodex-3,then supplemented with 100 mL/Lfetal calf serum(FCS)or 100 mL/L porcineportal vein serum(PPVS)respectively.Inspheroidal aggregate culture hepatocytes wereinoculated into 100 mL siliconized flasks at aconcentration of 5.0×10~6/mL.RESULTS In culture on microcarriershepatocytes tended to aggregate on Cytodex-3obviously after being inoculated.Typical multi-cellular aggregated spheroids could be found inthe two systems 24 h-48 h after hepatocyteswere cultured.The morphological charact-eristics and synthetic functions were maintainedfor 5 wk in FCS culture system and 8 wk in PPVSculture system.In spheroidal aggregate cultureabout 80%-90% isolated hepatocytes becameaggregated spheroids 24h after cultured insuspension and mean diameter of the spheroidswas 100μm.The relationship among thehepatocytes resembled that in the liver in vivo.Synthetic functions of albumin and urea of the spheroids were twice those of hepatocytescultured on monolayers.CONCLUSION As high-yields and high-activitymodes of culture on microcarriers or inspheroidal aggregate culture with portal veinserum are promising to provide biomaterials forbioartificial liver(BAL)efficiently.
基金supported by grants from the National Natural Science Foundation of China (30672043, 30772105)the National 863 program of China (2008AA02Z417)
文摘BACKGROUND: The bioartificial liver (BAL) is considered a possible alternative method for treating liver failure. The core of the BAL system is culturing liver cells in vitro with high density and activity. Microcarrier culture is a mode of high-density culture. We set out to prepare a novel porous microcarrier to improve the activity of liver cells in vitro. METHODS: Chitosan was used to prepare a novel porous spherical microcarrier with interconnected structure. The chitosan porous microcarriers (CPMs) were modified with gelatin to improve their biocompatibility. CPMs were co-cultured with liver cells, HL-7702 (L-02), to evaluate their effect on cell culture. RESULTS: The average size of the CPMs was about 400 μm in diameter and their apertures were less than 30 μm. The pores of the microcarrier were interconnected. After fixation by sodium tripolyphosphate, the structure of the first freeze-dried CPMs was stable. To further improve the biocompatibility, the surface of CPMs was modified with gelatin through chemical crosslinking (GM-CPMs). Comparing the proliferation curves of L-02 cells cultured on simple CPMs, GM-CPMs and tissue culture polystyrene (TCPS, a mode of planar cell culture), the proliferation rates were similar in the first 5 days and the cells proliferated until day 8 in culture with microcarriers. The OD value of liver cells cultured on GM-CPMs was 1.97-fold higher than that on TCPS culture at day 8. Levels of urea and albumin in supernatants of cells cultured on GM-CPMs increased steadily for 8 days, and were clearly higher than those of cells cultured on TCPS (P<0.05).CONCLUSIONS: The novel CPMs were promising microcarriers for hepatocyte culture and the GM-CPM seemed better. Porous microcarrier culture was beneficial for hepatocyte function and activity.
文摘Bacterial infection causes wound inflammation and makes angiogenesis difficult.It is urgent to develop effectively antibacterial and pro-vascularizing dressings for wound healing.The hydrogel is developed with pH-responsive drug-releasing microcarriers which were loaded with vascular endothelial growth factor(VEGF)that promotes angiogenesis and actively respond to wound pH for control and prolong VEGF release.The surfaces of the microcarriers were coated with polydopamine which can reduce the silver nanoparticles(AgNPs)in situ,and dynamically crosslink with the polyacrylamide,which forms a stable slow-release system with different release behavior for the VEGF and AgNPs.The hydrogel inhib-ited bacterial formation and accelerated wound healing.With the hydrogel dressing,83.3%±4.29%of the wound heals at day 7,which is 40.9%±8.5%higher than the non-treatment group in defect infected model.The antibacterial properties of hydrogel down-regulate early inflammation-related cytokines,and the release of VEGF in the middle and late phases of wound healing in response to pH changes pro-motes angiogenesis and up-regulate the expression of angiogenesis-associated cytokine.The sequential release of antibacterial agents and pro-vascularizing agents in response to the change in wound microen-vironmental cues facilitate temporally controlled therapy that suites the need of different wound healing phases.Collectively,the hydrogel loaded with multifunctional microcarriers that enable controlled release of AgNPs and VEGF is an effective system for treating infected wounds.
文摘An rCHO cell line expressing recombinant human prourokinase （pro-UK） at the level of 5μg/ 10^6cells/d was cultivated on Cytopore cellulose porous microcarriers in a 7.5L Biostat CT stirred tank reactor. A periodic pressure oscillation of 0.04 MPa and 0.04 Hz was adopted to introduce a physical stimulus on the rCHO cells and to improve mass transfer characteristic between cells and medium in the process of porous microcarrier CHO cell culture. Compared to constant pressure culture, the oscillation culture didn＇t influence specific cell growth rate significantly, but could enhance the pro-UK specific production by 10% - 40%, and reduce production of lactate by 10% - 30%. In the perfusion culture of recombinant CHO cell with serum-free medium for 67 days, cell density could reach 2.64×10^7/ml, the maximal prourokinase concentration in harvested supernatant was about 118mg/L, a total of 21.1 grams of prourokinase was produced in 313 liters of supernatant. In conclusion, the perfusion cell culture with periodic pressure oscillation can enhance the production of recombinant protein and increase the reactor specific productivity.
文摘CD-1, a genetically-engineered CHO cell line, was cultivated with a Biosilon microcarrier culture system.We successfully cultivated CD-1 cells to a very high density (over1×107cells/ml). Prourokinase was stably secreted at about 180 IU/ 1e6 cells/24 h. Experiments showed that CD-1 cells growing on Biosilon microcarriers were able to spontaneously release from the microcarriers, then reatthch and proliferate on fresh microcarriers. This makes it very easy to scale up preduction. The microcarriers could be reused several times without affecting adhesion. proliferation and prourokinase secretion. With CMPECC membrane radial flow chromatography and MPG chromatography, the prourokinase in conditioned medium could be purified to a specific activity of 1×105 IU/mg of protein. The purification factor was about 600 fold, and approxiamately 90 % of the biological activity was recovered.
文摘Genetically-engineered CHO cell lines, rβ- 13 and CLF-8B2, were cultivated with the MC- 1 microcarrier culture system. The cell density could be enhanced by increasing the concentration of microcarrier. At a microcarrier concentration of 10 mg/ml. the cell density could reach 4 to 5 × 106 cells/ml. It was shown that these cell lines would spontaneously release from the microcarrier to attach to and proliferate on fresh microcarriers. We were thus able to scale up cultivation using a simple method. i. e. by adding fresh microcarriers and medium directly into the culture system to about 2, 4 or 8 times the original volume. Using a perfusion culture system. we have successfully cultivated CLF-8B2 cells in a 2 L bioreactor for several weeks at medium perfusion rates of 0. 5 to 3working volumes. Prourokinase was stably secreted.
文摘objective: To cultivate human liver cell line (CL-1) on microcarriers and study the synthetic and transformational function of this culture system. Methods:CL-1 were cultivated on Cytodex-3 microcarriers. The cell growth was kinetically inspected with light microscope and scanning electronic microscope on the lst, 3rd, 5th, 7th, 9th day, and the amount of diazepam transformation and albumin synthesis were deter mined at the same time. Results:On 7th day after inoculating, the CL-1 cell density could reach 2. 16 ×106/ ml ; the amount of diazepam trans formation was 619 μg and albumin synthesis 78. 23 μg. Conclusion:CL-1 can be cultivated to a high density on microcarriers and has hepatic specific biotransformation and biosynthesis functions. So the culture system may be further studied for being used as the biomaterial of bioartificial liver.
文摘The fact of microcarrier (MC) culture introduces new possibilities and makes possible the practical high-yield culture of anchorage-dependent cells has generated a considerable focus in this study. The objective of this research was to study the comparison of Vero cell growth on different types of commercial microcarriers;Cytodex-1, Cytodex-3, Hil-lex? II and Plastic Plus in spinner vessel and two liters bioreactor cultured for 96 hours. Biological performance of the microcarrier in RPMI media showed the preference of Vero cell grew on Cytodex 3 microcarriers with highest maximum viable cell number (2.4 × 105 cells/ml) followed by Cytodex 1, Hillex and Plustic Plus. Vero cell on Cyto-dex-3 data in spinner flask was compared in bioreactor and result showed higher viable cell number in biorector. Thus, this dextran-crosslink gelatin microcarrier (Cytodex 3) provided the best surface for cell attachment and fast proliferation. At the end of this cell growth improvement will be used for virus transfection producing a vaccine in bioreactor.
文摘The upstream process was carried out in an animal component-free medium on Cytodex 1 microcarriers. Recombinant trypsin is a non-animal derived protease used as an alternative to animal-derived trypsin. To inactivate recombinant trypsin, a soybean trypsin inhibitor (STI) should be added to the medium. A protocol was first tested in T-flasks and then passaged to 500 mL and 3 L spinner flasks. Cell detachment was completed in 10 - 12 min, and 0.4 g/L STI was added to a 3L spinner, and cells were transferred into a 30 L stirred tank bioreactor. On day 5, the cell density had reached its maximum (around 1.8 × 106 cells/mL). At an MOI of 0.3 with serum-free medium conditions, cell infection yielded a maximal rabies virus titer of 1.82 × 10<sup>7</sup> FFU/mL at 5 days. All cell culture conditions and virus growth kinetics in serum-free media were investigated. In conclusion, Vero cells were grown on Cytodex 1 with serum-free media and a high amount of rabies virus was obtained. A mouse challenge was used to determine the immune response to an inactivated rabies virus vaccine candidate. Also, we evaluated inactive rabies vaccine candidate safety, and immunogenicity in mice, sheep, horses, and cattle. We found that no horses, sheep, or cattle who were given vaccine IM at 3.2 IU/dose exhibited any clinical sign of disease and all developed high VNA titers (up to 10.03 IU/mL) by 3 - 4 WPI. After the accelerated stability studies, the lyophilized inactivated rabies vaccine candidate showed enough antigenic potency (2.6 IU/mL) in the mouse challenge test. Also, 18-month long-term stability studies showed enough immune response (1.93 IU/mL) on day 14. The activity of the vaccine candidate showed a good immune response and safety criteria that meet WHO requirements. This is the first pilot-scale mammalian cell-based viral rabies vaccine production study in Türkiye that used microcarriers.
基金The Natural Science Foundation of China (No. 30070222)
文摘The fructose modified chitosan microcarries (CMs) were prepared by the reaction of glutaraldehyde with fructose-modified chitosan. Various factors that influence the preparation were studied and the reaction conditions were optimized. Morphology of rat hepatocytes cultured on CMs was observed using phase contrast microscope and scanning electron microscope, and the metabolic activities were measured. Rat hepatocytes cultured on CMs retained the spherical shape as they have in vivo and had high metabolic activities. Fructose can enhance the metabolic activity of hepatocytes and the modified CMs are promising scaffold for hepatocytes attachment.
基金The National Natural Science Foundation of China(No.29776027).
文摘Using polyvinyl alcohol (PVA) as raw material and vacuum pump oil as oil phase medium, PVA-based microcarriers were prepared by suspension method. The diameters of the beads were 100-180μm. LO2 cells were cultured on PVA-based microcarriers and cytodexIII microcarriers. Morphology, attachment and growth rate of LO2 cells were studied.
基金supported by the National Key Research and Development Program of China(2022YFA1105300)the National Natural Science Foundation of China(52073060,61927805 and 82400718)+5 种基金the Nanjing Medical Science and Technique Development Foundation(ZKX21019)the Clinical Trials from Nanjing Drum Tower Hospital(2022-LCYJ-ZD-01)supported by the Research Project(347897)Solution for Health Profile(336355)InFLAMES Flagship(337531)"Printed Intelligence Infrastructure"(PII-FIRI)"from Research Council of Finland.
文摘Long-term exposure to ultraviolet radiation compromises skin structural integrity and results in disruption of normal physiological functions.Stem cells have gained attention in anti-photoaging,while controlling the tissue mechanical microenvironment of cell delivery sites is crucial for regulating cell fate and achieving optimal therapeutic performances.Here,we introduce a mechanically regulated human recombinant collagen(RHC)microcarrier generated through microfluidics,which is capable of modulating stem cell differentiation to treat photoaged skin.By controlling the cross-linking parameters,the mechanical properties of microcarriers could precisely tuned to optimize the stem cell differentiation.The microcarriers are surface functionalized with fibronectin(Fn)-platelet derived growth factor-BB(PDGF-BB)to facilitate adipose derived mesenchymal stem cells(Ad-MSCs)loading.In in vivo experiments,subcutaneous injection of stem cell loaded RHC microcarriers significantly reduced skin wrinkles after ultraviolet-injury,effectively promoted collagen synthesis,and increased vascular density.These encouraging results indicate that the present mechanically regulated microcarriers have great potential to deliver stem cells and regulate their differentiation for anti-photoaging treatments.
基金supported by the National Natural Science Foundation of China(52173151,82002734,51803067)the Natural Science Foundation of Guangdong Province of China(2021A1515011084,2019A1515110312)+1 种基金the Fundamental Research Funds for the Central Universities(22qntd1302)the Shenzhen Outbound Postdoctoral Scientific Research Fund(SZBH202108).
文摘Cartilage tissues possess an extremely limited capacity for self-repair,and current clinical surgical approaches for treating articular cartilage defects can only provide short-term relief. Despite significantadvances in the field of cartilage tissue engineering, avoiding secondary damage caused by invasive surgical procedures remains achallenge. In this study, injectable cartilage microtissues were developed through 3D culture of rat bone marrow mesenchymal stemcells (BMSCs) within porous gelatin microcarriers (GMs) and induceddifferentiation. These microtissues were then injected for thepurpose of treating cartilage defects in vivo, via a minimally invasiveapproach. GMs were found to be noncytotoxic and favorable for cellattachment, proliferation and migration evaluated with BMSCs. Moreover, cartilage microtissues with a considerable number of cells andabundant extracellular matrix components were obtained from BMSC-laden GMs after induction differentiation culture for 28days. Notably,ATDC5 cells were complementally tested to verify that the GMs were conducive to cell attachment, proliferation, migration and chondrogenicdifferentiation. The microtissues obtained from BMSC-laden GMs were then injected into articular cartilage defect areas in rats and achievedsuperior performance in alleviating inflammation and repairing cartilage. These findings suggest that the use of injectable cartilagemicrotissues in this study may hold promise for enhancing the long-term outcomes of cartilage defect treatments while minimizing the risk ofsecondary damage associated with traditional surgical techniques.
基金supported by National Natural Science Foundation of China(Grant No.52273119,51973018)Key Research and Development Projects of People’s Liberation Army(BWS17J036)Beijing Science and Technology Project(Z191100002019017).
文摘Microcarrier applications have made great advances in tissue engineering in recent years, which can load cells,drugs, and bioactive factors. These microcarriers can be minimally injected into the defect to help reconstruct agood microenvironment for tissue repair. In order to achieve more ideal performance and face more complextissue damage, an increasing amount of effort has been focused on microcarriers that can actively respond toexternal stimuli. These microcarriers have the functions of directional movement, targeted enrichment, materialrelease control, and providing signals conducive to tissue repair. Given the high controllability and designabilityof magnetic and electroactive microcarriers, the research progress of these microcarriers is highlighted in thisreview. Their structure, function and applications, potential tissue repair mechanisms, and challenges are discussed.In summary, through the design with clinical translation ability, meaningful and comprehensiveexperimental characterization, and in-depth study and application of tissue repair mechanisms, stimuliresponsivemicrocarriers have great potential in tissue repair.
基金Faculty of Dentistry,National University of Singapore,Grant/Award Numbers:A-0002938-00-00,A-0006270-00-00。
文摘Conventional methods of stem cell therapy for tissue regeneration often face challenges,such as poor cell viability and integration posttransplantation.To address this,we proposed transplanting cells within synthetic microenviron-ments that maintain viability,cell phenotype,support extracellular matrix(ECM)secretion,and promote differentiation to enhance the regeneration of damaged host tissue.This hypothesis was tested in dental tissue regeneration using dental pulp stem cell-laden microcarriers(MCs)mixed in a gelatin methacrylate(GelMA)hydrogel as a delivery system.The combination of MCs and GelMA exhibited similar physical properties and favorable biological properties compared to GelMA alone.Specifically,cell-laden MC mixed into GelMA enhanced cell proliferation and ECM secretion and maintained a normal phenotype.Notably,MC-modified GelMA amplified odontogenic differentiation,mineralization,and vascular endothelial growth factor release.Moreover,the storage of MC-modified GelMA showed no detrimental effects on its injection force,cell viability,and mineralization potential,which demonstrates that the composite hydrogel is a promising injectable vehicle for therapeutic stem cell delivery.This strategy may be broadly applied to various tissues and organ systems,in which the provision and instruction of a cell population to participate in regeneration may be clinically useful.
