Objective To study the gene expressions of human osteoblasts during the construction of tissue engineered bone with the bioderived material. Methods The fetal osteoblasts were used to construct tissue engineered bone with the bio-derived material and then were cultured 2,4,6,8 and 10 days in vitro. Real-time PCR analysis indicated that Cbfa 1, Osterix, Collagen type Ⅰ,osteocalcin(OC) and Integrin α5 and β1 were present in osteoblasts with bio-derived materials.Results The change ofCbfa1 was consistent with the change of Osterix. On 2nd day and 8th day, the expression of Osterix in experimental group was higher than that in control group, P＜0.05. Collagen type Ⅰ’s change was consistent with change of OC expression, and its expression was higher in experimental group than that in control group on 2nd, 4th, 6th and 8th day. The Integrinexpression was high all along. Conclusion The important genes can be expressed normally by integrating osteoblasts with bioderived scaffolds. As skeleton tissue engineering scaffold, the bio-derived bone is conducive to keepthe osteoblast’s phenotype and differentiation with osteoconductive ability. The osteoblast can enter proliferation stage favorably and the scaffold materials exert no effects on it. Bio-derived bone can also supply more space for cellsto proliferate. The bio-derived materials promote osteoblasts adhesion.
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.
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 prevent early closure of growth plate and developmental deformities of limbs by allografts of cultured cartilages into growth plate defects of rabbits. METHODS Chondrocytes isolated from articular cartilage of 1-month rabbits formed cartilage after cultivation in centrifuge tubes. The cartilages cultured for two weeks were implanted into growth plate defects of proximal tibiae of 6-weeks rabbits. At 4th and 16th weeks, X-ray, histologic and immunohistochemical examination were performed. RESULTS The tibiae had no marked deformities after 4 weeks of operation. Histologic examinations showed that the defects were filled with cartilage. Immunohistochemical results of type II collagen were positive. The tibiae with allografts of cultured cartilages had no evident deformities after 16 weeks of operation. Histologic examination showed nearly closure of growth plates. On the contrary, the tibiae on control side formed severe deformities and growth plate were closed. CONCLUSION Allograft of cultured cartilages into growth plate defects may replace lost growth plate tissues, maintain normal growth of limbs and prevent developmental deformity.
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.
OBJECTIVE To investigate possibility of cartilage cultured in centrifuge tube as graft materials. METHODS: Articular chondrocytes isolated from a 3-week-old rabbit formed cartilage after cultivation for 2 weeks. Articular cartilage of humeral head, growth plate of proximal tibia and meniscus were collected from a 6-week-old rabbit. The ultrastructure of chondrocytes and extracellular matrix in the three kinds of cartilages and cultured cartilage were observed by transmission electronic microscopy. RESULTS: Cartilage cultured in centrifuge tube possessed unique ultrastructure and was similar to articular cartilage and growth plate, but it was markedly different from meniscus. The four kinds of cartilages were characteristic of respectively different chondrocytes and extracellular matrix. Cultured cartilage showed typical apoptosis of chondrocytes and "dark chondrocytes" appeared in growth plate. Condrocyte apoptosis was not seen in articular cartilage and meniscus. CONCLUSION: Cartilage cultured in centrifuge tube has unique ultrastructure and may be used as graft materials for articular cartilage and growth plate.
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.
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.