The influence of pH and fluid dynamics on the antibacterial efficacy of 45S5 Bioglass
The influence of pH and fluid dynamics on the antibacterial efficacy of 45S5 Bioglass
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DOI：
10.1088/1748-6041/11/1/015006
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发表时间：
2016-02-01
影响因子：
4
通讯作者：
Martin, Richard A.
中科院分区：
文献类型：
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作者：
Begum, Saima;Johnson, William E.;Martin, Richard A.
近年来，生物活性玻璃可能具有的潜在抗菌性能引起了人们的极大兴趣。然而，关于45S5 Bioglass(R)的抗菌效果，有几个相互矛盾的报告。关于其作用方式，人们提出了各种机制，如环境pH值的变化，渗透压的增加，以及可能破坏原核细胞壁从而使细菌失活的针状尖锐玻璃碎片。在这项当前的研究中，系统地研究了45S5 Bioglass(R)在一系列临床相关场景下对大肠杆菌NCTC 10538和金黄色葡萄球菌ATCO6538的抗菌效果，包括不同的Bioglass(R)浓度、Bioglass(R)与微生物的直接和间接接触、静态和摇动培养条件、升高和中和的pH环境。结果表明，在pH升高的条件下，Bioglass(R)颗粒对金黄色葡萄球菌没有抑菌作用，而对大肠杆菌有浓度依赖性的抑菌作用。然而，当介质的pH被中和时，抗菌活性就停止了。因此，目前这项研究的结果表明，Bioglass(R)的抗菌活性机制与环境pH的变化有关，这种环境由于系统的缓冲而不太可能在体内发生。
In recent years, there has been considerable interest in the potential antibacterial properties that bioactive glasses may possess. However, there have been several conflicting reports on the antibacterial efficacy of 45S5 Bioglass (R). Various mechanisms regarding its mode of action have been proposed, such as changes in the environmental pH, increased osmotic pressure, and 'needle-like' sharp glass debris which could potentially damage prokaryotic cell walls and thus inactivate bacteria. In this current study, a systematic investigation was undertaken on the antibacterial efficacy of 45S5 Bioglass (R) on Escherichia coli NCTC 10538 and Staphylococcus aureus ATCO 6538 under a range of clinically relevant scenarios including varying Bioglass (R) concentration, direct and indirect contact between Bioglass (R) and microorganisms, static and shaking incubation conditions, elevated and neutralised pH environments. The results demonstrated that, under elevated pH conditions, Bioglass (R) particles have no antibacterial effect on S. aureus while a concentration dependent antibacterial effect against E. coli was observed. However, the antibacterial activity ceased when the pH of the media was neutralised. The results of this current study, therefore, suggest that the mechanism of antibacterial activity of Bioglass (R) is associated with changes in the environmental pH; an environment that is less likely to occur in vivo due to buffering of the system.