硼硅酸盐生物活性玻璃多孔支架的制备

Preparation of Porous Scaffolds of Borosilicate Bioglass

Na_2O-CaO-SiO_2-P_2O_5-B_2O_3系硼硅酸盐生物玻璃是一类具有良好生物活性和降解性能的组织工程材料.本研究中,采用有机泡沫浸渍法,乙醇作溶剂,乙基纤维素作添加剂,将硼硅酸盐玻璃粉体制备成具有三维连通网状结构的组织工程多孔支架.通过调节浆料的固相含量和乙基纤维素含量,改善坯体的涂覆量,在支架孔径为300～500μm,孔隙率高于80%时,使支架抗压强度从0.03MPa提高到0.36MPa.根据蜂窝状结构模型分析,发现采用高强度玻璃,优化浆料是改善多孔材料结构和力学性能的有效途径.用该模型理论指导,由Na_2O-K_2O-MgO-CaO·SiO_2-P_2O_5-B_2O_3系统制成的另一种硼硅酸盐玻璃支架,其抗压强度可达5～8MPa.实验表明有机泡沫浸渍法在制备组织工程支架中有广泛的应用前景.

A borosilicate bioglass in Na2O-CaO-SiO2-P2O5-B2O3 system is a bioactive and biodegradable material for tissue engineering. In this study, the bioactive porous scaffolds with three-dimensional interconnection were fabricated by replication technique, using borosilicate bioglass powder to form slurry with ethanol as solvent and ethyl-cellulose as additive. The compressive strength of scaffolds increases from 0.03MPa to 0.36MPa by adjusting the slurry load, the solid concentration and the ethylcellulose concentration in the slurry, while the pore size of scaffolds remains in the rangeot 300-500μm and the porosity maintains over 80%. According the analysis on Cellular Structure Model, it is suggested that employing high strength glass and optimizing slurry composition are effective approaches to improve cellular structure and increase scaffold strength. The compressive strength of another borosilicate glass scaffolds made from Na2O-K2O-MgO-CaO-SiO2-P2O5-B2O3 system can reach 5-8MPa based on the theory. These experiments show that the replication technique is a promising way to prepare bioglass scaffolds.