An effective local drug delivery system remains an urgently needed product for the treatment of chronic osteomyelitis in the clinic. In this study, we developed an antibacterial functionalization bone graft by immobilizing levofloxacin hydrochloride-loaded mesoporous silica microspheres (LFH @ MSNs) on the surface of a nanohydroxyapatite/polyurethane (n-HA/PU) bioactive composite scaffold. Through pretreatment of the n-HA/PU scaffold by chitosan solution and subsequent crosslinking by vanillin, LFH @ MSNs were uniformly and stably immobilized on the scaffold surface. The results of drug release experiments showed that the release of LFH from LFH @ MSN-modified n-HA/PU scaffolds (LFH @ MSN/n HA/PU) lasted up to 42d. The antibacterial assays indicated that LFH @ MSN/n-HA/PU offers satisfactory antibacterial activity against both gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli) bacteria. The biosafety assays demonstrated that the LFH @ MSN/n-HA/PU scaffold could satisfy the requirements of the biosafety standards. The constructed LFH @ MSN/n-HA/PU porous scaffolds with an antibacterial surface and favorable biosafety are deemed a promising candidate for infectious bone defect repair.

中文翻译：

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通过将盐酸左氧氟沙星固定的中孔二氧化硅微球固定在多孔支架表面上，开发抗菌骨接枝。

有效的局部药物输送系统仍然是临床上治疗慢性骨髓炎迫切需要的产品。在这项研究中，我们通过将负载盐酸左氧氟沙星的介孔二氧化硅微球（LFH @ MSNs）固定在纳米羟基磷灰石/聚氨酯（n -HA / PU）生物活性复合支架的表面上，开发了一种抗菌功能化骨移植物。通过壳聚糖溶液预处理n- HA / PU支架并随后通过香兰素交联，将LFH @ MSNs均匀稳定地固定在支架表面。药物释放实验结果表明，LFH @ MSN修饰的n -HA / PU支架（LFH @ MSN / n）的释放。HA / PU）持续长达42d。抗菌测定表明，LFH @ MSN / n -HA / PU对革兰氏阳性（金黄色葡萄球菌）和革兰氏阴性（大肠杆菌）细菌均具有令人满意的抗菌活性。生物安全性测定表明，LFH @ MSN / n -HA / PU支架可以满足生物安全标准的要求。构建的具有抗菌表面和良好生物安全性的LFH @ MSN / n -HA / PU多孔支架被认为是感染性骨缺损修复的有希望的候选者。