Li Xu, Liu Kerh Li, Wang Miao, Wong Siew Yee, Tjiu Wuiwui Chauhari, He Chao Bin, Goh Suat Hong, Li Jun
Institute of Materials Research and Engineering, Agency for Science, Technology and Research, Singapore, Singapore.
Acta Biomater. 2009 Jul;5(6):2002-12. doi: 10.1016/j.actbio.2009.01.035. Epub 2009 Feb 1.
Natural source poly[(R)-3-hydroxybutyrate-co-(R)-3-hydroxyvalerate] (PHBV) with a low hydroxyvalerate (HV) content ( approximately 8wt.%) was modified by blending it with poly[(R)-3-hydroxybutyrate]-alt-poly(ethylene oxide) (HE) alternating block copolymer. We hypothesized that the adjoining PHB segments could improve the miscibility of the poly(ethylene oxide) segments of HE with the PHBV matrix and therefore improve the physical properties of the PHBV/HE blends. A differential scanning calorimetry study revealed the improved miscibility of PEO segments of HE characterized by the interference of the crystallization of PHBV. The decrease in water contact angle and the increase in equilibrium water uptake of the PHBV/HE blends indicated that both the surface and bulk hydrophilicity of PHBV could be improved through blending HE. The mechanical properties of the hydrated PHBV/HE blends were assessed by measuring their tensile strength. In contrast to the hydrated natural source PHBV, which failed in a brittle manner, the hydrated PHBV/HE blends were ductile. Their strain at break increased with increasing HE content, reaching a maximum of 394% at an HE content of 15wt.%. The excellent integrity of the PHBV/HE blends in water is attributed to the strong affinity between the PHB segments of HE and the PHBV matrix. Platelet adhesion on the film surface of the PHBV/HE blends was investigated in vitro to evaluate their blood compatibility. The results demonstrated that the PHBV/HE blends effectively resisted the adhesion of platelets due to the anchored PEO segments from HE on the film surface.
将低羟基戊酸（HV）含量（约8wt.%）的天然来源聚[（R）-3-羟基丁酸酯-co-（R）-3-羟基戊酸酯]（PHBV）与聚[（R）-3-羟基丁酸酯]-alt-聚环氧乙烷（HE）交替嵌段共聚物共混进行改性。我们推测，相邻的聚（3-羟基丁酸酯，PHB）链段可以改善HE的聚环氧乙烷链段与PHBV基体的相容性，从而改善PHBV/HE共混物的物理性能。差示扫描量热法研究表明，HE的聚环氧乙烷链段的相容性得到改善，其特征在于PHBV结晶的干扰。PHBV/HE共混物的水接触角减小和平衡吸水率增加表明，通过共混HE可以改善PHBV的表面和本体亲水性。通过测量其拉伸强度来评估水合PHBV/HE共混物的力学性能。与以脆性方式失效的水合天然来源PHBV不同，水合PHBV/HE共混物具有韧性。它们的断裂应变随HE含量的增加而增加，在HE含量为15wt.%时达到最大值394%。PHBV/HE共混物在水中的优异完整性归因于HE的PHB链段与PHBV基体之间的强亲和力。体外研究了血小板在PHBV/HE共混物膜表面的粘附，以评估其血液相容性。结果表明，由于HE的PEO链段锚定在膜表面，PHBV/HE共混物有效地抵抗了血小板的粘附。
