Jaakkola T, Rich J, Tirri T, Närhi T, Jokinen M, Seppälä J, Yli-Urpo A
Department of Prosthetic Dentistry and Biomaterials Research, Institute of Dentistry, University of Turku, Lemminkäisenkatu 2, 20520 Turku, Finland.
Biomaterials. 2004 Feb;25(4):575-81. doi: 10.1016/s0142-9612(03)00558-1.
Bioactive properties of composites containing poly(epsilon-caprolactone-co-DL-lactide) with molar ratio 96/4 and bioactive glass (BAG), S53P4, were tested in vitro. The glass content in the tested materials was 40, 60 or 70 wt%, and two granule size ranges (<45 and 90-315 microm) were used. The composites were analysed for their apatite-forming ability. This was determined as a function of time by the dissolution pattern of Si and Ca ions and structural changes on the specimen surfaces. Composite specimens were immersed in simulated body fluid at 37 degrees C for up to 6 months. The changes in Si and Ca concentrations of the immersion medium were determined with UV-Vis and atomic absorption spectrophotometry. The calcium phosphate precipitation and apatite formation were evaluated by scanning electron microscopy (SEM) and infra-red spectroscopy (IR) using the attenuated total reflectance (ATR) system. The SEM and SEM-EDX analysis of the depositions formed on the composite surfaces was in line with the changes in ion concentrations. The clearest results with IR were seen in the material containing 60 wt% small glass particles. The results indicate that composites containing over 40 wt% BAG granules are bioactive, and that a higher BAG surface area/volume ratio favors the apatite formation in vitro.
对含有摩尔比为96/4的聚（ε-己内酯-co-DL-丙交酯）和生物活性玻璃（BAG）S53P4的复合材料的生物活性特性进行了体外测试。测试材料中的玻璃含量为40%、60%或70%（重量），并使用了两个颗粒尺寸范围（<45微米和90 - 315微米）。分析了复合材料的磷灰石形成能力。这是根据Si和Ca离子的溶解模式以及样品表面的结构变化随时间确定的。将复合材料样品在37℃下浸泡在模拟体液中长达6个月。用紫外可见分光光度法和原子吸收分光光度法测定浸泡介质中Si和Ca浓度的变化。通过扫描电子显微镜（SEM）和使用衰减全反射（ATR）系统的红外光谱（IR）评估磷酸钙沉淀和磷灰石形成。对复合材料表面形成的沉积物进行的SEM和SEM-EDX分析与离子浓度的变化一致。在含有60%（重量）小玻璃颗粒的材料中，IR得到的结果最清晰。结果表明，含有超过40%（重量）BAG颗粒的复合材料具有生物活性，并且较高的BAG表面积/体积比有利于体外磷灰石的形成。
