In this study, porous hollow hydroxyapatite (HAp) microspheres are prepared using chitosan microspheres as novel sacrificial templates and their microstructure, biocompatibility, and drug delivery properties are evaluated. Scanning electron microscope (SEM) observations show that HAp microspheres are spherical in morphology with a diameter of 100–300 μm and have a porous and core–shell structure. X-ray diffractometer patterns show that HAp microspheres consist of apatite phase. MTT assay indicates that HAp microspheres are biocompatible and have no significant cytotoxicity. SEM observations show that HAp microspheres support attachment and proliferation of osteoblast MC3T3-E1 cells. After being soaked in the solution of tetracycline hydrochloride (TH, model drug), HAp microspheres adsorb TH with an adsorption capacity of 47% to derive TH-loaded HAp microspheres. When exposed to two types of representative bacteria: Escherichia coli and Staphylococcus aureus, TH-loaded HAp microspheres maintain the biological activity of TH to inhibit the growth of bacteria.

中文翻译：

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多孔中空羟基磷灰石微球的简易合成、体外生物相容性和抗菌活性

在这项研究中，使用壳聚糖微球作为新型牺牲模板制备了多孔空心羟基磷灰石 (HAp) 微球，并评估了它们的微观结构、生物相容性和药物递送特性。扫描电子显微镜（SEM）观察表明，HAp微球形态为球形，直径为100-300μm，具有多孔核壳结构。X 射线衍射图显示 HAp 微球由磷灰石相组成。MTT 法表明 HAp 微球具有生物相容性，没有明显的细胞毒性。SEM 观察表明，HAp 微球支持成骨细胞 MC3T3-E1 细胞的附着和增殖。在盐酸四环素（TH，model drug）溶液中浸泡后，HAp 微球吸附 TH，吸附容量为 47%，得到载有 TH 的 HAp 微球。当暴露于两种代表性细菌时：大肠杆菌和金黄色葡萄球菌，负载TH的HAp微球保持TH的生物活性以抑制细菌的生长。