掺锶半水硫酸钙的制备及其抗菌性能

Preparation and Antibacterial Properties of Sr-doped Calcium Sulfate Hemihydrate

为了研究掺锶半水硫酸钙生物材料的制备、生物学活性及其抗菌性能,本研究采用共沉淀法制备了四种不同锶摩尔掺杂率(0、2.5%、5%、10%)的半水硫酸钙材料,运用理化表征与模拟体液浸泡实验考察了材料的化学组成、微结构及体外生物学活性,并对材料抑制金葡菌的性能进行了分析。结果显示,首先通过共沉淀法成功合成的含锶半水硫酸钙中均出现硫酸锶,这表明锶直接与硫酸根结合发生了化学沉积,与半水硫酸钙形成两相复合材料。其次,早期阶段未掺锶的硫酸钙样品降解速率明显快于掺锶硫酸钙,锶离子掺杂率提高抑制硫酸钙降解速率更为显著;后期阶段未掺锶硫酸钙样品的降解速率明显低于掺锶硫酸钙,锶离子掺杂率越高,硫酸钙降解速率越快。再次,四种固化物的力学性能变化与降解速率相对应,同时掺锶半水硫酸钙表面诱导沉积类骨羟基磷灰石晶体更为显著,并且抑菌作用更强,掺杂10%锶的半水硫酸钙表现出优良的生物活性和抑菌特性。研究结果表明,锶掺杂硫酸钙实为半水硫酸钙与硫酸锶的复合材料,该种复合材料能有效调节硫酸钙生物材料的降解性、增强其生物活性及抗菌性能,将有助于解决包括骨髓炎损伤区抗感染及骨再生修复相关临床需求,具有重要价值和应用前景。

In order to study the preparation,bioactivity and antibacterial property of strontium-doped calcium sulfate hemihydrate cement biomaterials,four groups of calcium sulfate hemihydrate(CSH)with different strontium molar contents(0%,2.5%,5%,10%)were prepared by a co-precipitation method,and the chemical composition,microstructure and in vitro bioactivity of the biomaterials were investigated by physicochemical characterizations and simulated body fluid immersion test;also,the antibacterial effect of the biomaterials against Staphylococcus aureus were analyzed.The experimental results showed that strontium sulfate(SS)was present in the strontium-doped CSH biomaterials via co-precipitation method,which indicated that strontium ions were chemically deposited directly in combination with sulfate groups,and thus form produce a CSH-based biphasic composite biomaterial.Meanwhile,the biodegradation rate of strontium-undoped samples was significantly faster than that of strontium-doped samples in the early stage,and the increased strontium dopants could significantly inhibit the biodegradation rate of samples.The biodegradation rate of strontium-undoped samples in the later stage was significantly lower than that of strontium-doped samples,and the higher was the doping rate of strontium ions,the faster was the biodegradation rate of the samples.Moreover,the mechanical properties of the four groups of samples were consistent with their biodegradation rate,and the surface of strontium-doped samples could induce more biomimetic hydroxyapatite and showed the stronger antibacterial effect;in fact,the samples doped with 10%strontium showed excellent bioactive and antibacterial properties.These studies show that strontium-doped CSH-based biomaterials is actually a composite of CSH and SS,which can effectively regulate the biodegradability of calcium sulfate biomaterials,enhance their bioactive and antibacterial properties.These new biomaterials will help to solve the clinical needs involving in the anti-infection and bone repair in osteomyelitic injury conditions,accompanying with important application prospects.