羟基磷灰石/聚乳酸/聚氨酯生物材料的降解性能

以聚乳酸(PDLLA)和聚氨酯(PU)为基体,将纳米羟基磷灰石(n-HA)与其复合,制备了多孔n-HA/PDLLA/PU生物材料,通过模拟体液(SBF)浸泡试验评估材料的生物降解性和矿化活性,测定了降解过程中材料的吸水率和pH变化,以及浸泡前后的质量损失。通过红外光谱分析生物材料浸泡前后结构组成变化,采用热重分析(TG)材料降解前后的热稳定性,并用扫描电镜观察材料降解前后表面形貌特征。结果表明,n-HA/PDLLA/PU生物材料在模拟体液中随浸泡时间的延长由外到内不断降解,可以通过控制PDLLA的含量调节材料的降解速率;随着PDLLA和PU的水解以及n-HA形成新的结晶,生物材料降解后热稳定性降低。

Biodegradation of Hydroxyapatite/Poly(DL-Lactide)/Polyurethane Biomaterials

Porous polyurethane/poly(D,L-lactide)(PU/PDLLA) biomaterials containing nano-Hydroxyapatite(n-HA) were fabricated.The degradation in vitro of the samples was characterized quantitatively by measuring the water absorption,pH value and weight loss as a function of different immersion time in simulated body fluid(SBF).The constitution and thermal behavior of the biomaterials were analyzed by IR and thermo gravimetric analysis(TGA),the surface appearance was analyzed by scanning electron microscopy(SEM).It is found that with increasing immersion time in the SBF,the biomaterial generates degradation from inside to outside,and the degradation rate can be controlled by different PDLLA content.With the PDLLA and PU hydrolyzed and the new crystallization formation of n-HA,thermal stability of the biomaterial is decreased with increasing immersing time.