Fabrication of scaffolds made of bioresorbable polymer for bone and cartilage regeneration and its bone reconstruction using transplantation with the blood vessel pattern.

本研究的目的是：(1)制备生物可吸收聚合物支架用于骨和软骨再生；(2)在体内评价生物可吸收聚合物支架与培养骨髓细胞的骨再生效果。采用溶剂铸造颗粒浸出法制备多孔生物可吸收聚合物支架：将聚（D， l -丙交酯-羟基乙酸）（PLGA）（75/25）溶于二甲亚砜中，将溶液倒入充满不同尺寸（0.6、1.0、2.0 mm）蔗糖晶体的模具中。然后将模具转移到-18℃的冰箱中放置1h，使混合物凝固。将PLGA沉淀，用蒸馏水从沉淀的PLGA中浸出糖晶。用扫描电镜对样品进行观察。结果表明，PLGA镁铁沸石（PLGA）具有连续的孔隙，且孔隙大小随蔗糖晶粒尺寸的增大而增大。研究结果表明，晶体尺寸可以调节PLGA的平均孔径和孔隙率。我们还通过将低结晶碳酸盐磷灰石颗粒混合到PLGA中，制备了具有骨导电性的多孔生物可吸收聚合物支架（chapp -PLGA）（75/25）。将大鼠骨髓细胞植入chapp - plga （chapp - plga带细胞）中，在添加抗坏血酸、β -甘油磷酸酯和地塞米松的培养基中培养2周。将PLGA、chapp -PLGA和chapp -PLGA带细胞植入7周龄同基因大鼠体内。在植入后3、8周进行体内成骨组织学观察。虽然PLGA中未观察到骨形成，但chapp -PLGA和chapp -PLGA中有细胞的新骨形成。在有细胞的chapp - plga情况下，骨的形成量比没有细胞的chapp - plga更快。综上所述，chapp - plga似乎是一种很有希望的骨和软骨再生支架替代品。需要进一步研究chapp - plga的长期吸收和成骨的稳定性。少

The purposes of this study are (1) to fabricate scaffold with bioresorbable polymer for bone and cartilage regeneration and (2) to evaluate bone regeneration by the bioresorbable polymer scaffold and cultured bone marrow cells in vivo.Porous bioresorbable polymer scaffold was fabricated by solvent-casting particulate leaching methods : after poly(D,L-lactide-co-glycolic acid)(PLGA)(75/25) was dissolved in dimethyl sulfoxide, the solution was poured into a mold filled up with the various sizes (0.6, 1.0, 2.0 mm) of sucrose crystals. Then, the mold was transferred to a fridge at -18℃ for 1h to set the mixture. The PLGA was precipitated and the sugar crystals were leached out of the precipitated PLGA in distilled water. The specimens were observed by scanning electron microscopy. As the result, the PLGA madoreporite (PLGA) had continuous pores, and the pore size increased with the crystal size of sucrose. This result indicates that average diameter of diameter of the pore and porosity of … More PLGA could be adjusted by the crystal size. We also fabricated porous bioresorbable polymer scaffold (CHAp-PLGA) with osteoconductivity by mixing low crystalline carbonate apatite particles into PLGA (75/25).The rat bone marrow cells were seeded into CHAp-PLGA (CHAp-PLGA with cells) and, then cultured in medium supplemented with ascorbic acid, beta-glycerophosphate, and dexamethasone for 2 weeks. PLGA, CHAp-PLGA and CHAp-PLGA with cells were implanted into 7-week-old syngeneic rats. The osteogenesis in vivo was histologically evaluated at 3, 8 weeks after the implantation. Although no bone formation was observed in PLGA, new bone formation was seen in CHAp-PLGA and CHAp-PLGA with cells. In the case of CHAp-PLGA with cells, the larger amount of bone was formed more rapidly than CHAp-PLGA without cells.As a conclusion, CHAp-PLGA seemed to become a promising alternative of the scaffold for bone and cartilage regeneration. Further studies of the long-term resorption of CHAp-PLGA and stability of the formed bone will be needed. Less