Biomed Mater. 2018 Jan 30;13(2):025010. doi: 10.1088/1748-605X/aa9a84.
The aim of this work was to produce hydroxyapatite powder (HA) containing the dry extract of green and red propolis, and to evaluate the possible bactericidal activity of these materials over a short period of time through a fast release system. The ethanolic extracts of green and red propolis (EEP) were incorporated into the material by spray drying. After release tests, powders containing dry EEP were characterized regarding the content of total phenolics and flavonoids. Material characterization was undertaken by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The antimicrobial activity was evaluated by plate colony counting, minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) against Staphylococcus aureus (S. aureus). The cytotoxicity of the materials was determined by the neutral red incorporation method. The materials showed apparently spherical morphology, indicating a decrease in the degree of agglomeration with the addition of propolis. Characteristic HA and propolis functional groups were observed in the FTIR. The materials showed a higher release of phenolics and lower amounts of flavonoids when compared to the EEP, with the higher amounts of flavonoids observed for HA with red propolis. A bactericidal effect was observed for all materials within the interval of 0.5 and 1 h, showing lower inhibitory activity (MIC) and higher bactericidal activity (MBC) when compared to the EEP, with the best results attributed to HA with red propolis. The IC values (which is the concentration needed to inhibit cell growth by 50%) obtained from the cytotoxicity assay for HA with the green and red propolis lay between MIC and MCB. Considering these results, it is suggested that HA and propolis may be used as a possible antimicrobial agent, inhibiting the growth of S. aureus, although further in vivo biocompatibility should be investigated before using this material as a medical device with bactericidal potential.
本工作的目的是制备载有绿蜂胶和红蜂胶干提取物的羟基磷灰石（HA）粉末，并通过快速释放系统评估这些材料在短时间内的可能杀菌活性。采用喷雾干燥法将绿蜂胶和红蜂胶（EEP）的乙醇提取物掺入材料中。释放试验后，对含有干EEP 的粉末进行总酚和类黄酮含量的特征描述。通过扫描电子显微镜（SEM）和傅里叶变换红外光谱（FTIR）进行材料特性研究。通过平板菌落计数、最低抑菌浓度（MIC）和最低杀菌浓度（MBC）评估抗菌活性，以金黄色葡萄球菌（S. aureus）为目标菌。通过中性红掺入法测定材料的细胞毒性。材料表现出明显的球形形态，表明加入蜂胶后团聚程度降低。在 FTIR 中观察到 HA 和蜂胶的特征官能团。与 EEP 相比，材料表现出较高的酚类释放和较低的类黄酮含量，而添加红蜂胶的 HA 观察到较高的类黄酮含量。所有材料在 0.5 和 1 小时的间隔内均表现出杀菌作用，与 EEP 相比，MIC 表现出较低的抑制活性和较高的杀菌活性，MBC 表现出较高的杀菌活性，而添加红蜂胶的 HA 表现出最佳效果。细胞毒性试验中获得的 HA 与绿蜂胶和红蜂胶的 IC 值（即抑制细胞生长 50%所需的浓度）介于 MIC 和 MCB 之间。考虑到这些结果，建议 HA 和蜂胶可用作可能的抗菌剂，抑制金黄色葡萄球菌的生长，尽管在将该材料用作具有杀菌潜力的医疗设备之前，应进一步研究体内生物相容性。
