热致相分离法制备聚羟基丁酸酯-羟基戊酸酯纳米纤维支架及其表征

背景:由微生物合成的聚羟基丁酸酯-羟基戊酸酯(polyhydroxybutyrate-hydroxyvalerate,PHBV)是聚羟基脂肪酸酯的一种,具有良好的生物相容性和机械强度。目的:探讨热致相分离法制备PHBV纳米纤维支架的方法及结晶行为。方法:采用扫描电镜、广角X射线衍射、红外光谱和差示扫描量热分析分析基质的结构。结果与结论:凝胶温度对纳米纤维的结晶和热性质有很大的影响。当凝胶温度较高时,PHBV纳米纤维的结晶度和晶粒尺寸随着凝胶温度的降低而减小,而且随着凝胶温度的降低,其结晶的有序性增加。说明温度对PHBV支架形貌和结构的影响可能对PHBV支架的性质-包括生物降解性和对细胞活性的生物应答反应有一定的积极意义。

Preparation and characterization of poly(hydroxybutyrate-co-hydroxyvalerate) nanofiber scaffolds using thermally induced phase separation method

BACKGROUND: Poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) is a polymer of microbial source with excellent biocompatibility and processing performance, which has great potential to be used as a biological material. OBJECTIVE: To investigate the synthesis methods and crystallization of nanofibrous matrix of a semicrystalline biopolyester PHBV via thermally induced phase separation. METHODS: The formation of the matrix was characterized by scanning electron microscopy, wide angle X-ray diffraction, Fourier transform infrared and differential scanning calorimetry. RESULTS AND CONCLUSION: The quenching/gelation temperatures showed a great effect on the crystallization and thermal property of the nanofibers, then affected the morphology of the scaffolds. The crystallization of the PHBV matrix during the phase separation process primarily involved HB units with small amounts of crystals incorporating HV units at higher gelation temperatures. When the quenching/gelation temperature decreased, the crystallinity and crystallite size were decreased but better crystalline perfection was obtained by excluding HV units from the PHB lattice. Meanwhile, cells experimental results show that nanofibers structure of scaffolds are really more conducive to cell adhesion and growth. The morphological and structural dependence on temperature may provide a simple way to fine tune the properties of PHBV scaffolds including biodegradability and bioresponsiveness to cellular activity.