Objective To study the effect of various storage methods on cellular compatibility of bio-derived bone. Methods Freeze dried biomaterials had been stored in two different preservation solutions for three months, while the biomaterials stored for the same time were observed as control group. The experiment was divided into groups A, B, C and D according to different storage methods (group A: with materials stored in preservation solution 1; group B:with materials stored in preservation solution 2; group C:with freeze-dried materials; and group D: simple osteoblasts). Osteoblasts at 2×106/ml had been cocultured with materials for 1, 3, 5, and 7 days.The cell-material complexwas observed under phase microscope and electronic scanning microscope to evaluate the adhesion and growth of osteoblasts; the cell viability and alkaline phosphatase(ALP) activity were measured,and the cell cycle wasanalysed by flow cytometer.WTHZ〗Results Osteoblasts adhered to materials preserved by different methods,differentiated and proliferated in the hole of materials. The difference of cell viability was not significant between three groups on day 1 andday 3. The cell viability of osteoblasts adhered to three materials was Agt;Cgt;B group on day 5 and day 7 (Plt;0.01，Plt;0.05). The ALP activity of osteoblasts adhered to three materials was Agt;Cgt;B group on day 7(Plt;0.01).The cell cycle of differentgroups did not change significantly,the abnormal cells were not seen. Conclusion The choice of proper preservation solution can optimize the cellular compatibility of bio-derived bone.
OBJECTIVE: To investigate the influence of tissue engineered tendon on subgroup of T lymphocytes and its receptor in Roman chickens. METHODS: The flexor digitorum profundus of the third toes of right feet in 75 Roman chickens were resected and made 2.5 cm defects as experimental model. They were randomly divided into five groups according to five repair methods: no operation (group A), autograft (group B), fresh allograft (group C), polymer combined with allogenous tendon cells (group D), derived tendon materials combined with allogenous tendon cells (group E). The proliferation and transformation of lymphocytes and contribution of CD4+, CD8+, CD28 and T cell receptor (TCR) were detected to study the immune response. RESULTS: The CD4+, CD8+ and TCR of group D and E were increased slightly than that of group B after 7 days, while after 14 days, those data decreased gradually and no significant difference between tissue engineered tendon and autografts (P gt; 0.05), and there was significant difference between fresh allograft and tissue engineered tendon (P lt; 0.05). Lymphocytes transformation induced by conA also showed no significant difference between tissue engineered tendon and autografts (P gt; 0.05). CONCLUSION: Tendon cells are hypoantigen cells, there are less secretion of soluble antigen or antigen chips dropped out from cells. Tissue engineered tendon has excellent biocompatibility.
OBJECTIVE: To explore the relationship between characteristics of transformed cell and tumorigenicity. METHODS: Documents about transformed cell and tumorigenicity were reviewed in detail. RESULTS: Normal biological characteristics and cell function could be maintained in non-tumorigenic transformed cell, but it was changed markedly in malignant transformed cell. CONCLUSION: Non-tumorigenic transformed cell can be served as a standard cell line to study the function and growth characteristics of normal cell.
OBJECTIVE: From the point of view of material science, the methods of tissue repair and defect reconstruct were discussed, including mesenchymal stem cells (MSCs), growth factors, gene therapy and tissue engineered tissue. METHODS: The advances in tissue engineering technologies were introduced based on the recent literature. RESULTS: Tissue engineering should solve the design and preparation of molecular scaffold, tissue vascularization and dynamic culture of cell on the scaffolds in vitro. CONCLUSION: Biomaterials play an important role in the tissue engineering. They can be used as the matrices of MSCs, the delivery carrier of growth factor, the culture scaffold of cell in bioreactors and delivery carrier of gene encoding growth factors.
Objective Engineer heart tissue (EHT) was constructed with mesenchymal stem cells (MSCs) and poly lacticacidCOglycolic acid (PLGA), and grafted onto the surface of myocardial infarction rats. We hypothesized that great omentum wrapping would increase EHT blood supply and ameliorate EHT microenvironment which is in favor of cardiac collagen remodling and heart function. We hope that omentun wrapped EHT could provide a valuable strategy for surgically myocardial infarction therapy. Methods MSCs were isolated from SD rats.Eight weeks after SD rats were subjected to left anterior descending (LAD) ligation, 18 rats were enrolled and divided into three groups, group A(n=6): great omentum wrapped MSCsPLGA EHT implantation; group B (n=6):MSCsPLGA EHT implantation; control group (n=6): the myocardial infarction; the sham group (n=6): only opened and closed chest, underwent LAD ligation, but no EHT implantation. Four weeks after transplantation, the following variables were evaluated: specimen stained with picrosirius red, left ventricle function evaluated by echocardiography, infarction ventricular wall motion by color kinesis (CK). Results Hearts of group A showed significantly less fibrosis than group B and control group (Plt;0.05). Infarction ventricular wall motion assessed by CK indicated significantly improvement in group A compared with group B and control group (Plt;0.05). Four weeks after transplantation, cardiac echocardiography showed left ventricle ejection fraction was lower in control group and group B compared with group A (Plt;0.05). Conclusion Transplantation of MSCsPLGA EHT with great omentum wrapping ameliorated infarction ventricular collagen remodeling, ameliorated infarction ventricular wall motion and preserved left ventricular function.
Objective To introduce the current development of periodontal regeneration. Methods The recent l iterature about advances in the regeneration of periodontium using tissue engineering was extensively reviewed and new technologies that will lead to further advances in periodontal therapy was investigated. Results The cells, appropriate signals,scaffold and blood supply play fundamental roles in periodontal regeneration. Furthermore, interreaction of these factors, such as cells modified by growth factor gene or growth factor del ivered by scaffold, will enhance their effects in tissue regeneration. Conclusion Periodontal tissue engineering have great potential and promising future in periodontal regeneration and therapy.
ObjectiveTo comprehensively analyze the recent advancements in the field of mesenchymal stem cells (MSCs) aging,and summary its achievements and its difficulty at the present. MethodsThe literature about MSCs aging was reviewed and analyzed. ResultsInducible telomerase reactivation of MSCs is successful to extend the life span of senescent cells,but it also has potential safety hazard.The age range presented in the research of age-related cell senescence is inconsistent,resulting in different outcomes.Many ways to improve cell in vitro culture conditions will help delay aging.Recent research indicates that oxidative stress theory is seemed to not completely explain cell aging. ConclusionFurther research of MSCs aging mechanism will help the tissue engineering transform to clinical application.
Objective To comment on the recent advances of production and application of the bio-derived scaffold in the tissue engineered peripheral nerve. Methods The recent articles were systematically analyzed, and then the production methods of the bio-derived scaffold and its application to the tissue engineered peripheral nerve were evaluated and prospected. Results B iological tissues were processed by some methods to produce the bio-derived materials. These mat erials could maintain the structure and components of the tissues. Moreover, the immunogenicity of these materials was reduced. Conclusion Application of the bio-derived materials is a trend in the fabricating scaffold of the tissue en gineered peripheral nerve.
OBJECTIVE: To build the trestle of tissue engineering for skin with the collagen. METHODS: The collagen was obtained from the baby cattle hide pretreated by Na2S and elastinase and Protease M, then the collagen was dissolved in 0.5 mol/L acetic acid solution. The collagen was treated with Protease N to minimize its immunogenicity. The resulting collagen could be used to build the trestle of tissue engineering for skin because of good biocompatibility. The collagen molecular weight and structure were analyzed by SDS-PAGE. The bioactivity of trestle was tested in the experiment of the mice wound healing and the cell implantation. RESULTS: The SDS-PAGE result of the collagen treated by Protease M showed the typical spectrum of type I collagen. The built trestle was a collagen sponge matrix in which micropore size was 50-200 microns. It could accelerate wound healing and the implanted fibroblasts could proliferate well. CONCLUSION: The collagen treated by Protease N can get good biocompatibilily and is suitable for building the trestles of tissue engineering for skin with good bioactivity.
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.