Liu Kaixin, Lu Xin, Guo Xudong, Yang Yi, Liu Wanying, Song Hongbin, Zhao Rongtao
Chinese PLA Center for Disease Control and Prevention, Beijing 100071, China.
The Fifth Medical Center of Chinese PLA General Hospital, Beijing 100071, China.
Pharmaceutics. 2025 Jun 5;17(6):743. doi: 10.3390/pharmaceutics17060743.
Intracellular bacteria frequently result in chronic and recurrent infections. MRSA is one of the most prevalent facultative intracellular bacteria in clinical infections. The drug resistance of MRSA and the difficulty of most antibiotics in entering cells result in a suboptimal clinical efficacy of antibiotics in the treatment of intracellular MRSA. Bacteriophages represent a promising alternative therapy in the context of the current antimicrobial resistance crisis. Nevertheless, the low efficiency of phage entry into cells and their rapid inactivation remain challenges in the treatment of intracellular MRSA using phages. The utilization of functionalized carriers for the delivery of phages into cells and their protection represents a feasible strategy. In this study, a new MRSA bacteriophage (vB_SauS_PHM) was isolated from hospital sewage, exhibiting the characteristics of short incubation period, large lytic amount, and good environmental tolerance. Subsequently, vB_SauS_PHM was encapsulated by TAT peptide-functionalized liposomes through microfluidic technology and size-exclusion chromatography (SEC), forming a phage delivery system, designated TAT-Lip@PHM. The encapsulation rate of the phage by TAT-Lip@PHM was 20.3%, and the cell entry efficiency was ≥90% after 8 h. The 24 h eradication rate of 300 μg/mL TAT-Lip@PHM against intracellular MRSA was 94.05% (superior to the 21.24% and 44.90% of vB_SauS_PHM and Lip@PHM, respectively), while the mammalian cell activity was >85% after 24 h incubation. The TAT-Lip@PHM effectively delivered the phage into the cell and showed an excellent killing effect on intracellular MRSA with low cytotoxicity. This work provides a technical reference for the application of phages in the treatment of intracellular bacterial infection.
胞内细菌常常导致慢性和复发性感染。耐甲氧西林金黄色葡萄球菌（MRSA）是临床感染中最普遍的兼性胞内细菌之一。MRSA的耐药性以及大多数抗生素难以进入细胞，导致抗生素在治疗胞内MRSA时临床疗效欠佳。在当前抗菌药物耐药危机的背景下，噬菌体是一种有前景的替代疗法。然而，噬菌体进入细胞的效率低以及它们迅速失活，仍然是使用噬菌体治疗胞内MRSA的挑战。利用功能化载体将噬菌体递送至细胞并对其进行保护是一种可行的策略。在本研究中，从医院污水中分离出一种新的MRSA噬菌体（vB_SauS_PHM），其具有潜伏期短、裂解量高和环境耐受性良好的特点。随后，通过微流控技术和尺寸排阻色谱法（SEC），用TAT肽功能化脂质体包裹vB_SauS_PHM，形成一种噬菌体递送系统，命名为TAT-Lip@PHM。TAT-Lip@PHM对噬菌体的包封率为20.3%，8小时后细胞进入效率≥90%。300μg/mL TAT-Lip@PHM对胞内MRSA的24小时根除率为94.05%（分别优于vB_SauS_PHM的21.24%和Lip@PHM的44.90%），而在孵育24小时后哺乳动物细胞活性>85%。TAT-Lip@PHM有效地将噬菌体递送至细胞内，并对胞内MRSA显示出优异的杀伤效果，且细胞毒性低。这项工作为噬菌体在治疗胞内细菌感染中的应用提供了技术参考。
