RESUMO
Objective To investigate the effects of collagen concentration and pre-freezing temperature on structure and properties of the scaffold. Method A series of porous collagen scaffolds were fabricated with different collagen concentration and pre-freezing temperature by freezing-drying. The effective pore sizes and other properties of the porous scaffolds were evaluated and compared with each other. Chondrocytes of rabbit were separated and cultured on these scaffolds to evaluate their biocompatibility. Result The collagen scaffolds had interconnected pore ranging from 50 to 200 ?m in pore size. With increasing the collagen concentration density and tensile strength of the scaffolds increased, while pore size and degradation rate of the scaffolds decreased, as well as become less homogeneous. Reducing pre-freezing temperature resulted in smaller poresize and slower degradation rate of scaffolds. MTT analyses demonstrated that all the scaffolds availed to cell attachment and proliferation, while increasing collagen concentration and decreasing pre-freezing temperature evidently restrained chondrocytes attachment and proliferation. Conclusion The collagen concentration and pre-freezing temperature have crucial influence on the structure and properties of collagen scaffolds. The suitable collagen scaffolds were obtained by adjusting the collagen concentration and pre-freezing temperature. The bigger of the pore size was. The faster cell proliferation was achieved.
RESUMO
Objective To investigate the feasibility of repairing the radius defect with inductive bone regeneration membrane combined with freezed allogenic bone. Methods Preparation PLGA/bBMP+IGF-Ⅱ+ bFGF complosite was prepared as artificial periosteum. Twenty seven rabbits with 1.0 cm long right radius segmental osteoperiosteum defect were werved as the animal model, and randomly assigned to 3 groups with 9 in eath group; Group A: the defects were connected with the PLGA/bBMP+IGF-Ⅱ+bFGF membrane and allogenic bone; Group B: the defects were treated with the PLGA/bBMP+IGF-Ⅱ+bFGF membrane; Group C: the defects were implanted only woth allogenic bone grafts. Animals were killed at 2, 4, 8 weeks postoperation respectively. The healing was study with radiological, histological and immunological methods. Results The osteogenic ability in PLGA/bBMP+IGF-Ⅱ+bFGF group was superior to that in the other groups. The defects of group A ware fully repaired at week 8; bony bridging under remodeling was observed in group B; and the putrescence of allogenic bone which was packaged by mass of connective tissue was observed with group C; Group A caused lower titer of antibody than group C and inhibited lymphocytes reproduction in vitro; There was significant difference between group A and group C. Conclusion PLGA/bBMP+IGF-Ⅱ+bFGF artificial periosteum had provided a excellent osteoinduction condition. Artificial periosteum combined with freezed allogenic bone can effectively promote the rapair of radius defects of rabbit.