Chen L J, Wang M
School of Mechanical and Production Engineering, Nanyang Technological University, Singapore.
Biomaterials. 2002 Jul;23(13):2631-9. doi: 10.1016/s0142-9612(01)00394-5.
In recent years, emphasis in biomaterials engineering has moved from materials that remain stable in the biological environment to materials that can degrade in the human body. Biodegradable materials are designed to degrade gradually and be replaced eventually by newly formed tissue in the body. In this investigation, two particulate bioactive ceramics, i.e., hydroxyapatite (HA) and tricalcium phosphate (TCP), were incorporated into polyhydroxybutyrate-polyhydroxyvalerate (PHB-PHV), which is a biodegradable copolymer. to produce new biomaterials for potential medical applications. All raw materials were commercially available and they were characterised prior to composite production. HA/PHB-PHV and TCP/PHB-PHV composites containiing up to 30 vol% of the bioceramics were produced through an established procedure. Compounded and compression moulded materials were evaluated using various techniques including thermogravimatric analysis, scanning electron microscopy, differential scanning calorimetry and dynamic mechanical analysis. The results showed that intended compositions of composites had been achieved and bioceramic particles were well distributed in the polymer. The degradation temperature of PHB-PHV was significantly reduced by the incorporation of bioceramics, while the melting temperature was slightly affected by the addition of bioceramics. The crystallinity of PHB-PHV was also varied with the presence of HA or TCP particles. The storage modulus and loss modulus of the composites increased with the increase in HA or TCP content. Composites containing the highest percentage of bioceramics exhibited the highest stiffness. Preliminary in vitro study indicated enhanced ability of the composites to induce the formation of bone-like apatite on their surfaces.
近年来，生物材料工程的重点已从在生物环境中保持稳定的材料转向可在人体中降解的材料。可生物降解材料的设计目的是逐渐降解，并最终被体内新形成的组织所取代。在本研究中，将两种颗粒状生物活性陶瓷，即羟基磷灰石（HA）和磷酸三钙（TCP），掺入聚羟基丁酸酯-聚羟基戊酸酯（PHB-PHV）中，PHB-PHV是一种可生物降解的共聚物，以生产用于潜在医学应用的新型生物材料。所有原材料均有商业供应，并且在复合材料生产之前对其进行了表征。通过既定程序制备了含有高达30体积%生物陶瓷的HA/PHB-PHV和TCP/PHB-PHV复合材料。使用包括热重分析、扫描电子显微镜、差示扫描量热法和动态力学分析在内的各种技术对复合和压缩模塑材料进行了评估。结果表明，已实现了复合材料的预期组成，并且生物陶瓷颗粒在聚合物中分布良好。生物陶瓷的掺入显著降低了PHB-PHV的降解温度，而生物陶瓷的添加对熔点有轻微影响。PHB-PHV的结晶度也随HA或TCP颗粒的存在而变化。复合材料的储能模量和损耗模量随着HA或TCP含量的增加而增加。含有最高百分比生物陶瓷的复合材料表现出最高的刚度。初步体外研究表明，复合材料在其表面诱导形成类骨磷灰石的能力增强。
