The extracellular matrix (ECM) plays a pivotal role in regulating cellular behavior and driving tissue regeneration. Its unique structural characteristics and bioactivity not only provide physical support for cell growth, but also orchestrate tissue repair and functional reconstruction through multiple signaling pathways. This review systematically synthesizes preparation strategies for natural and engineered ECM materials from the perspective of ECM-mediated tissue regeneration mechanisms, with particular emphasis on recent advances in component preservation, structural biomimicry, and functional optimization. Furthermore, it delves into the application potential of cutting-edge technologies—including artificial intelligence, flexible electronics, and organoids—in ECM engineering, while critically analyzing the standardization and safety challenges hindering clinical translation. This article aims to provide a theoretical foundation and reference for constructing next-generation ECM-based regenerative medicine platforms.
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.
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 investigate the effect of WO-1 on the proliferation and differentiation of human embryonic osteoblasts (HEO) and to provide research methods of bone tissue engineering. Methods HEO were isolated from periosteum and calvaria and then cultrued in vitro. The doseeffect relationship between WO-1 concentration and biological effect of HEO was evaluated by growth curve and 3 H-TdR count. The effect of WO-1 on cell activity and proliferation was investigated by cloning efficiency,cell cycle analysis was determined by flow cytometer and morphological was examined through transmission electron microscope. Moreover, the effect of WO-1 on osteoblastic function was evaluated at protein and mRNA levels by ALP activity, 3 H-proline incorporation, osteocalcin secretion (RIA) and mRNA expression of type I collagen and osteocalcin (RT-PCR). Results The proliferation of HEO was inhibited in high concentration of WO-1,while it was promoted in low concentration of WO-1. The optimal dose was 8 μg/ml, and there was dose-effect relationship in the certain range of WO-1 concentration (0.25 μg/ml to 8 μg/ml). In 8 μg/ml of WO-1, the cloning efficiency and cloning volume of HEO were inereased, population doubling time was decreased.All indexes of ostoblastic function including ALP activity, type I collagen synthesis and osteocalcin secertion were inereased, the more sufficed cell organs were observed under transmission electron microscope than control group(P＜0.05). Conclusion WO-1 can promote the cell activity and proliferation of HEO cultured in vitro inlow concentration, enhance the synthesis of extracellular mamix, such as type Icollagen and osteocalcin, and accelerate the mineralization of osteoid. WO-1 can be used as a stimulant of proliferation and differentiation of HEO in the research of bone tissue engineering, which provide the theoretical basis in clinical application.
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.
【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.
ObjectiveTo prepare the small intestinal submucosa (SIS)-silk composite scaffold for anterior cruciate ligament (ACL) reconstruction, and to evaluate its properties of biomechanics, biocompatibility, and the influence on synovial fluid leaking into tibia tunnel so as to provide a better choice in the clinical application of ACL reconstruction. MethodsThe silk was used to remove sericin and then weaved as silk scaffold, which was surrounded cylindrically by SIS to prepare a composite scaffold. The property of biomechanics was evaluated by biomechanical testing system. The cell biocompatibility of scaffolds was evaluated by live/dead staining and the cell counting kit 8 (CCK- 8). Thirty 6-week-old Sprague Dawley rats were randomly assigned to 2 groups (n=15). The silk scaffold (S group) and composite scaffold (SS group) were subcutaneously implanted. At 2, 4, and 8 weeks after implanted, the specimen were harvested for HE staining to observe the biocompatibility. Another 20 28-week-old New Zealand white rabbits were randomly assigned to the S group and SS group (n=20), and the silk scaffold and composite scaffold were used for ACL reconstruction respectively in 2 groups. Furthermore, a bone window was made on the tibia tunnel. At last, the electric resistance of tendon graft in the bone window was measured and recorded at different time points after 5 mL of 10% NaCl or 5 mL of ink solution was irrigated into the joint cavity recspectively. ResultsThe gross observation showed that the composite scaffold consisted of the helical silk bundle inside which was surrounded by SIS. The maximal load of silk scaffold and composite scaffold was respectively (138.62±11.41) N and (137.05±16.95) N, showing no significant difference (P>0.05); the stiffness was respectively (24.65±2.62) N/mm and (24.21±2.39) N/mm, showing no significant difference (P>0.05). The live/dead staining showed that the cells had good activity on both scaffolds. However, the cells on the composite scaffold had better extensibility. In addition, the cell proliferation curve indicated that no significant difference in the absorbance (A) values was founded between groups at various time points (P>0.05). HE staining showed less inflammatory cells and much more angiogenesis in SS group than in S group at 2, 4, and 8 weeks after subcutaneously implanted (P<0.05), indicating good biocompatibility. Additionally, the starting time points of electric resistance decrease and the ink leakage were both significantly later in SS group than in S group (P<0.05). The duration of ink leakage was significantly longer in SS group than in S group (P<0.05). ConclusionThe SIS-silk composite scaffold has excellent biomechanical properties and biocompatibility and early vacularization after in vivo implantation. Moreover, it can reducing the leakage of synovial fluid into tibia tunnel at the early stage of ACL reconstruction. So it is promising to be an ideal ACL scaffold.
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.