新型骨与软骨组织工程支架材料制备及其性能研究

Preparation and properties of novel scaffold composites for bone and cartilage tissue engineering

目的 研制符合骨与软骨组织工程制备技术要求的新型支架复合材料 ;并确定其性能与结构优化设计的主要参数指标。方法 按不同CPPf(聚磷酸钙纤维 ) /PLLA(L 聚乳酸 )重量比及相同CPPf +PLLA/NaCl颗粒重量比 ,采用溶铸颗粒沥取 (Solvent castingparticulte leaching)法制备系列CPPf/PLLA支架复合材料 ;液体置换法、压缩性能测试及扫描电子显微镜观测其密度、孔隙度、压缩模量及微结构特征 ;材料样品体外人工降解液直接浸渍法判定其生物降解性能 ,并观测其生物降解率、压缩模量及微结构改变。结果 系列支架材料密度为 0 10 8～ 0 16 5g/cm3 ,孔隙度 87 17%～ 93 2 4% ,压缩模量为 5 19～ 7 89MP ,横截面微结构由微孔海绵状过渡为纤维网状。随着支架材料在人工降解液中降解时间的延长 ,其降解率以 0 %～ 13 2 %线性递增 ;压缩模量呈线性降低至 1 10～ 2 78MP ;材料横截面微结构则发生相应改变。结论 CPPf/PLLA支架复合材料具有高孔隙度的三维立体结构 ,良好的抗压缩性能和生物降解性能 ,经进一步优化设计后 ,可成为结构和性能符合各项要求的新型骨与软骨组织工程支架材料。

Objective To prepare novel scaffold composites for bone and cartilage tissue engineering and to study the effects of its component contents on the mechanical properties and microstructure of the scaffold. Methods The scaffold composites of calcium polyphosphate fiber/poly-L-lactic acid (CPPf/PLLA) with different weight ratio were prepared by using solvent-casting particulate-leaching method with CPPf+PLLA/NaCl particulates at same weight ratio. Density, porosity, compressive modulus and microstructure of the scaffold composites were tested and analyzed with liquid replacement, mechanical testing and scaning electron microscopy. The biodegradability was evaluated by samples being soaked into artificial degradation solusion at 37 ℃ in vitro . Results The scaffold composites CPPf/PLLA had the density of 0.108-0.165 g/cm 3, porosity of 87.17%-93.24%, compressive modulus of 5.19-7.89 MP and microporous sponge structure to fibrous network in microstructure of cross sections. The re-enforcement fiber CPPf in the scaffold composites significantly enhanced the beginning of biodegradation and increased the biodegradation rate by 0%-13.2% in a content-dependent manner. The compressive modulus of CPPf/PLLA showed a linear reduce to 1.10-2.78 MP along with the degradation time. And the changes of microstructure were consistent with the changes of biodegradation rate and compressive modulus. Conclusion The scaffold composites CPPf/PLLA have a 3-D network structure with high porosity, sound compressive modulus and good biodegradability. After further optimization in their structure and properties, they may be regarded as novel scaffold composites to satisfy the bone and cartilage tissue engineering.