Misra Superb K, Nazhat Showan N, Valappil Sabeel P, Moshrefi-Torbati M, Wood Robert J K, Roy Ipsita, Boccaccini Aldo R
Department of Materials, Imperial College London, London, UK.
Biomacromolecules. 2007 Jul;8(7):2112-9. doi: 10.1021/bm0701954. Epub 2007 May 27.
Bacterially derived poly(3-hydroxybutyrate) (P(3HB)) has been used to produce composite films by incorporating Bioglass particles (<5 microm) in 5 and 20 wt % concentrations. P(3HB) was produced using a large scale fermentation technique. The polymer was extracted using the Soxhlet technique and was found to have similar thermal and structural properties to the commercially available P(3HB). The effects of adding Bioglass on the microstructure surface and thermal and mechanical properties were examined using differential scanning calorimetry, dynamic mechanical analysis (DMA), X-ray diffraction, surface interferometry, electron microscopy, and nanoindentation. The addition of increasing concentrations of Bioglass in the polymer matrix reduced the degree of crystallinity of the polymer as well as caused an increase in the glass transition temperature as determined by DMA. The presence of Bioglass particulates reduced the Young's modulus of the composite. The storage modulus and the loss modulus, however, increased with the addition of 20 wt % Bioglass. A short period (28 days) in vitro bioactivity study in simulated body fluid confirmed the bioactivity of the composites, demonstrated by the formation of hydroxyapatite crystals on the composites' surface.
细菌衍生的聚（3-羟基丁酸酯）（P(3HB)）已被用于通过掺入浓度为5%和20%（重量）的生物玻璃颗粒（<5微米）来制备复合薄膜。P(3HB)是采用大规模发酵技术生产的。该聚合物使用索氏提取技术进行提取，发现其热性能和结构性能与市售的P(3HB)相似。使用差示扫描量热法、动态力学分析（DMA）、X射线衍射、表面干涉测量、电子显微镜和纳米压痕等方法研究了添加生物玻璃对微观结构表面以及热性能和力学性能的影响。在聚合物基体中增加生物玻璃的浓度会降低聚合物的结晶度，并如DMA所测定的那样导致玻璃化转变温度升高。生物玻璃颗粒的存在降低了复合材料的杨氏模量。然而，储能模量和损耗模量随着添加20%（重量）的生物玻璃而增加。在模拟体液中进行的为期28天的短期体外生物活性研究证实了复合材料的生物活性，这通过在复合材料表面形成羟基磷灰石晶体得以证明。
