Department of Mining and Metallurgical Engineering, Amirkabir University of Technology, 424 Hafez Ave., Tehran 15875-4413, Iran; Department of Materials Engineering, Imam Khomeini International University, Qazvin 34149-16818, Iran.
Department of Mining and Metallurgical Engineering, Amirkabir University of Technology, 424 Hafez Ave., Tehran 15875-4413, Iran.
Mater Sci Eng C Mater Biol Appl. 2018 Oct 1;91:349-360. doi: 10.1016/j.msec.2018.05.058. Epub 2018 May 18.
Lithium and strontium up to 10 mol% have been substituted for calcium in 58S bioactive glasses in order to enhance specific biological properties such as proliferation, alkaline phosphatase (ALP) activity of cells as well as antibacterial activity. In-vitro formation of hydroxyapatite was studied using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), inductively coupled plasma atomic emission spectrometry (ICP-AES) and scanning electron microscopy (SEM). Substitution of either Li or Sr for Ca in the composition had a retarding effect on the bioactivity while Li decreased and Sr increased the rate of ion release in the simulated body fluid solution. The dissolution rate showed to be inversely proportional to oxygen density of the bioactive glasses. The proposed mechanisms for the lowered bioactivity are a lower supersaturation degree for nucleation of apatite in Li substituted bioactive glasses and blocking of the active growth sites of calcium phosphate by Sr in Sr substituted bioactive glasses. The proliferation rate and alkaline phosphate activity of osteoblast cell line MC3T3-E1 treated with Li and Sr bioactive glasses were studied. 3-(4,5dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and alkaline phosphate assay showed that all synthesized bioactive glasses with exception of 58S with 10 mol% SrO, exhibited statistically significant increase in both cell proliferation and alkaline phosphatase activity. Finally, 58S bioactive glass with 5 mol% LiO substitution for CaO was considered as a potential biomaterial in bone repair/regeneration therapies with enhanced biocompatibility, and alkaline phosphate activity, with a negligible loss in the bioactivity compared to the 58S bioglass. At the same time this composition had the highest antibacterial activity against methicillin-resistant Staphylococcus aureus bacteria among all synthesized Li and Sr substituted bioactive glasses.
为了增强特定的生物学特性，如细胞增殖、碱性磷酸酶（ALP）活性和抗菌活性，在 58S 生物活性玻璃中用锂和锶取代了高达 10mol%的钙。使用 X 射线衍射（XRD）、傅里叶变换红外光谱（FTIR）、电感耦合等离子体原子发射光谱（ICP-AES）和扫描电子显微镜（SEM）研究了羟基磷灰石的体外形成。在组成中用 Li 或 Sr 取代 Ca 会延迟生物活性，而 Li 降低且 Sr 增加在模拟体液溶液中的离子释放速率。溶解速率与生物活性玻璃的氧密度成反比。提出的降低生物活性的机制是在 Li 取代的生物活性玻璃中，磷灰石成核的过饱和度较低，以及 Sr 取代的生物活性玻璃中钙磷酸盐的活性生长点被阻断。用 Li 和 Sr 生物活性玻璃处理成骨细胞系 MC3T3-E1 的增殖率和碱性磷酸酶活性进行了研究。3-(4,5-二甲基噻唑-2-基)-2,5-二苯基四氮唑溴盐（MTT）和碱性磷酸酶测定表明，除了 58S 中含有 10mol% SrO 的生物活性玻璃外，所有合成的生物活性玻璃均显示出细胞增殖和碱性磷酸酶活性的统计学显著增加。最后，58S 生物活性玻璃中用 5mol% LiO 取代 CaO 被认为是具有增强的生物相容性和碱性磷酸酶活性的骨修复/再生治疗中的潜在生物材料，与 58S 生物玻璃相比，生物活性的损失可以忽略不计。同时，该组成在所有合成的 Li 和 Sr 取代的生物活性玻璃中对耐甲氧西林金黄色葡萄球菌细菌具有最高的抗菌活性。
