通过化学发泡-冷冻干燥-粒子滤出复合法制备聚乳酸(PLLA)大孔支架,然后在大孔内以海藻酸钠(SA)、碳酸钙、葡萄糖酸内酯(GDL)为原料,通过原位相转变制备海藻酸钙水凝胶/聚乳酸复合材料(CA/PLLA);分别利用SEM、压缩强度测试和细胞培养对CA/PLLA支架的形貌、力学性能及生物相容性进行了研究。结果表明:PLLA具有直径小于2mm、孔道相互连通的孔洞,且在大孔中能够形成均匀的CA。CA/PLLA复合材料的压缩强度(2.74MPa)远大于单一的海藻酸钙水凝胶的压缩强度(0.10MPa)。在CA/PLLA复合支架中,软骨细胞呈簇状圆形生长状态,与其在天然软骨陷窝里生长状态一致。这种软硬结合、天然与合成高分子杂化的CA/PLLA复合材料的力学强度和生物相容性同时得到提高,可进一步作为骨和软骨修复材料研究。
In order to balance the mechanical strength and the biocompatibility,the calcium alginate hydrogel/poly L-lactic acid(CA/PLLA) composites were prepared.The macroporous PLLA scaffolds were fabricated using chemical foaming approach combined with the freeze-drying and particle-leaching method.Afterward sodium alginate,calcium carbonate and glucono-delta-lactone(GDL) were selected to produce the calcium alginate hydrogel using in-situ transformation method in the pores of the PLLA scaffolds.The surface structure,mechanical strength and the biocompatibility were explored by SEM,compressive strength test and the cell culture.The results show that the porous structure and the interconnected pore channels of PLLA are observed,showing that the diameter of the pores is below 2 mm,in which the calcium alginate hydrogel is capable of distributing evenly.The compressive strength of the composite material(2.74 MPa) is far better than that of the pure calcium alginate hydrogel(0.10 MPa).Chondrocytes are grown clustered and round in the composite scaffolds,resembling the growth state in natural cartilage lacuna.The CA/PLLA composite material,which is a combination of hard and soft materials and a hybrid of natural and synthetic polymers,with promoted mechanical strength and biocompatibility,can be researched further as a promising bone and cartilage repair material.