Objective To summarize the research progress of bio-derived materials used for bladder regeneration and repair. MethodsThe recent domestic and foreign sutudies on bio-derived materials used for bladder regeneration and repair, including classification, morphology optimization process, tissue regeneration strategies, and relevant clinical trials, were summarized and analyzed. ResultsNumerous types of bio-derived materials are employed in bladder regeneration and repair, characterized by their low immunogenicity and high inducible activity. Surface modification, gelation, and other morphology optimization process have significantly broadened the application scope of bio-derived materials. These advancements have effectively addressed complications, such as perforation and urolith formation, that may arise during bladder regeneration and repair. The strategy of tissue regeneration utilizing bio-derived materials, targeting the regeneration of bladder epithelium, smooth muscle, blood vessels, and nerves, offers a novel approach to achieving functional regeneration of bladder. Bio-derived materials show great promise for use in bladder regeneration and repair, yet the results from clinical trials with these materials have been less than satisfactory. ConclusionBio-derived materials are widely used in bladder regeneration and repair due to the good biocompatibility, low immunogenicity, and degradable properties, yet face a series of problems, and there are no commercialized bladder tissue engineering grafts used in clinical treatment.
ObjectiveTo review the recent research progress of different types of stem cells in the treatment of ischemic stroke.MethodsBy searching the PubMed database, a systematic review had been carried out for the results of applying different types of stem cells in the treatment of ischemic stroke between 2000 and 2020.ResultsStem cells can be transplanted via intracranial, intravascular, cerebrospinal fluid, and intranasal route in the treatment of ischemic stroke. Paracrine and cell replacement are the two major mechanisms of the therapy. The researches have mainly focused on utilization of neural stem cells, embryonic stem cells, and mesenchymal stem cells. Each has its own advantages and disadvantages in terms of capability of migration, survival rate, and safety. Certain stem cell therapies have completed phase one clinical trial.ConclusionStem cells transplantation is feasible and has a great potential for the treatment of ischemic stroke, albeit that certain obstacles, including the selection of stem cells, transplantation strategy, migration ability, survival rate, still wait to be solved.
Objective To summarize the role of Piezo mechanosensitive ion channels in the osteoarticular system, in order to provide reference for subsequent research. Methods Extensive literature review was conducted to summarize the structural characteristics, gating mechanisms, activators and blockers of Piezo ion channels, as well as their roles in the osteoarticular systems. Results The osteoarticular system is the main load-bearing and motor tissue of the body, and its ability to perceive and respond to mechanical stimuli is one of the guarantees for maintaining normal physiological functions of bones and joints. The occurrence and development of many osteoarticular diseases are closely related to abnormal mechanical loads. At present, research shows that Piezo mechanosensitive ion channels differentiate towards osteogenesis by responding to stretching stimuli and regulating cellular Ca2+ influx signals; and it affects the proliferation and migration of osteoblasts, maintaining bone homeostasis through cellular communication between osteoblasts-osteoclasts. Meanwhile, Piezo1 protein can indirectly participate in regulating the formation and activity of osteoclasts through its host cells, thereby regulating the process of bone remodeling. During mechanical stimulation, the Piezo1 ion channel maintains bone homeostasis by regulating the expressions of Akt and Wnt1 signaling pathways. The sensitivity of Piezo1/2 ion channels to high strain mechanical signals, as well as the increased sensitivity of Piezo1 ion channels to mechanical transduction mediated by Ca2+ influx and inflammatory signals in chondrocytes, is expected to become a new entry point for targeted prevention and treatment of osteoarthritis. But the specific way mechanical stimuli regulate the physiological/pathological processes of bones and joints still needs to be clarified. Conclusion Piezo mechanosensitive ion channels give the osteoarticular system with important abilities to perceive and respond to mechanical stress, playing a crucial mechanical sensing role in its cellular fate, bone development, and maintenance of bone and cartilage homeostasis.
OBJECTIVE: To explore the SV40-mediated immortalization, the related factors and their roles in cell immortalization. METHODS: The original articles about cell immortalization and replicative senescence in recent decade were reviewed. RESULTS: Cell immortalization was a multifaceted phenomenon, it was involved in viral DNA integration, activation of telomerase, inactivation of growth suppressors, and so on, and their roles were closely related. CONCLUSION: The research on cell immortalization may be expected to provide important insights into a broad range of cellular biological phenomenon, and the immortalized cells can play important roles in the research of cell engineering and tissue engineering as standard cells.
【Abstract】 Objective To review the recent progress of cell therapy in cl inical appl ications. Methods Therecent l iterature about cell therapy in cl inical appl ications was extensively reviewed. Results Based on the advances in cell biology, especially the rapid progress in stem cell biology, an increasing number of cl inical trials about cell therapy for management of various diseases, such as cardiovascular system diseases, neural system diseases, musculo-skeletal diseases, diabetes, stress urinary incontinence, and others, had been reported with encouraging results. All these showed that cell therapy had great potentials in cl inical appl ication. Conclusion Cell therapy provides a novel approach for the treatment of many human diseases. However, the mechanism remains to be fully elucidated.
Objective To compare biological characteristics between articular chondrocyte and meniscal fibrochondrocyte cultured in vitro andto investigate the possibility of using cultured cartilage as a substitute for meniscus.Methods Chondrocytes isolated from articular cartilage and meniscus of rabbits aged 3 weeks were respectively passaged in monolayer and cultured in centrifuge tube. Cartilages cultured in centrifuge tube and meniscus of rabbit aged 6 weeks were detected by histological examination and transmission electron microscopy. Growth curves of articular chondrocytes and meniscalfibrochondrocytes were compared; meanwhile, cell cycles of articular chondrocytes and meniscal fibrochondrocytes in passage 2and 4 were separately measured by flow cytometry.Results Articular chondrocytes in passage 4 were dedifferentiated. Articular chondrocytes formed cartilage 2 weeks after cultivation in centrifuge tube, but meniscal fibrochondrocytes could not generate cartilage. The differences in ultrastructure and histology obviously existed between cultured cartilage and meniscus; moreover, apoptosis of chondrocytes appeared in cultured cartilage. Proportion of subdiploid cells in articular chondrocytes passage 2 and 4 was markedly higher than that in passage 2 and 4 fibrochondrocytes(Plt;0.05). Conclusion Meniscal fibrochondrocytes can not form cartilage after cultivationin centrifuge tube, while cartilage cultured in centrifuge tube from articular chondrocytes can not be used as graft material for meniscus. Articular cartilage ismarkedly different from meniscus.
Objective To review the application of genipin for the modification of natural biomaterials as a crosslinking agent and progress in research. Methods Domestic and foreign literature on application of genipin for the modification of natural biomaterials as a crosslinking agent was thoroughly reviewed. Results Genipin is an effective natural crosslinking agent with a very low level of cytotoxicity compared with conventional synthetic crosslinking agents. Tissues fixed with genipin can maintain a high level of stability as well as resistance to enzymatic degradation. Conclusion Genipin is a promising substitute for conventional synthetic crosslinking agents, which has offered an alternative for modification of natural biomaterials for tissue engineering.
ObjectiveTo explore a simple and rapid pathological slices method to observe the porous structure and the composition distribution of composite materials. MethodsTaking polyurethane/small intestinal submucosa (PU/SIS) composite as an example, PU/SIS was OCT-embedded and sliced into sections by frozen section technology, after which general observation of the section integrity was carried out. After dyed with water-soluble eosin in alcoholic solution, the staining effect and the porous structure of the composite were observed under light field microscope. Sections were sealed with five different sealing methods. Group A: sealing piece using glycerogelatin method; group B: anhydrous alcohol dehydration→transparency using TO transparent reagent→sealing piece using neutral quick drying glue; group C: color separation using deionized water→air-drying→sealing piece using neutral quick drying glue; group D: air-drying→transparency using TO transparent reagent→sealing piece using neutral quick drying glue; group E: air-drying→sealing piece using neutral quick drying glue. Then, the morphology and the components distribution of the composite were observed under light field microscope, and the simple and feasible method was selected as optimum method. ResultsFrom general observation, the frozen section of the PU/SIS composite, which was 6 μm in thickness, was complete and continuous. Although the outline of the material and the porous structure in the sections could be observed clearly under light field microscope, the two components still could not be identified by using eosin staining method. After sealing piece, the material components in groups A, B, and C still could not be identified or be dissolved and deformed; the morphology of the material in groups D and E were preserved and the two components in the composite were clearly visible. ConclusionThe morphology and the components distribution of PU/SIS frozen sections can be characterized after soluble eosin staining and neutral quick drying glue sealing.
Objective To review and summarize the latest development of the therapy for the Duchenne muscular dystrophy (DMD). Methods Therecentlypublished articles related to the therapies for DMD were extensively reviewed and briefly summarized. Results The therapeutic approaches for DMD included the gene therapy, the cell therapy, and the pharmacological therapy. The gene therapy and the cell therapy were focused on the treatment for the cause of DMD by the delivery of the missing gene, the modification of the mutated gene, and the transfer of the normal cells including the stem cells, while the pharmacological therapy dealt with the downstream events caused by the dystrophin gene defect, slowed down the pathologic progress of DMD, and improved the DMD patient’s life quality and life span, by medication and other factor treatments. Conclusion There is still no cure for DMD because of various difficulties in replacing or repairing thedefected gene and of the multifaceted nature of the severe symptoms. Therefore,it is imperative for us to find out a more effective treatment that can solve these problems.
OBJECTIVE: To investigate the biological characteristics of continuously subcultured human embryonic skeletal myoblasts, and choose the optimal seeding cells for muscle tissue engineering. METHODS: Human embryonic skeletal myoblasts were subcultured in vitro. The growth curve, rate of myotube formation(RMF) were used to evaluate the proliferative and differentiation ability of myoblasts, and to investigate the influence of fibroblasts contamination on myoblasts. RESULTS: The beginning 6 passages of myoblasts showed b proliferative and differentiation ability. From the 8th to 20th passage, the rate of fibroblasts contamination was increased, it mainly showed the growth characteristics of fibroblasts with increased proliferation and low differentiation. After subcultured to the 20th passage, the degeneration of myoblasts was obvious. CONCLUSION: The myoblasts within 6 passages should be used as the seeding cells of muscle tissue engineering because of b proliferative ability and high rate of myotube formation.