Key Laboratory of Medicinal Resources and Natural Pharmaceutical Chemistry, Ministry of Education, College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, PR China.
Key Laboratory of Medicinal Resources and Natural Pharmaceutical Chemistry, Ministry of Education, College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, PR China.
Biomaterials. 2021 Oct;277:121124. doi: 10.1016/j.biomaterials.2021.121124. Epub 2021 Sep 10.
Precise targeting and high therapeutic efficiency are the major requisites of personalized cancer treatment. However, some unique features of the tumor microenvironment (TME) such as hypoxia, low pH and elevated interstitial fluid pressure cause cancer cells resistant to most therapies. Bacteria are increasingly being considered for targeted tumor therapy owing to their intrinsic tumor tropism, high motility as well as the ability to rapidly colonize in the favorable TME. Compared to other nano-strategies using peptides, aptamers, and other biomolecules, tumor-targeting bacteria are largely unaffected by the tumor cells and microenvironment. On the contrary, the hypoxic TME is highly conducive to the growth of facultative anaerobes and obligate anaerobes. Live bacteria can be further integrated with anti-cancer drugs and nanomaterials to increase the latter's targeted delivery and accumulation in the tumors. Furthermore, anaerobic and facultatively anaerobic bacteria have also been combined with other anti-cancer therapies to enhance therapeutic effects. In this review, we have summarized the applications and advantages of using bacteria for targeted tumor therapy (Scheme 1) in order to aid in the design of novel intelligent drug delivery systems. The current challenges and future prospects of tumor-targeting bacterial nanocarriers have also been discussed.
精准靶向和高效治疗是个性化癌症治疗的主要要求。然而，肿瘤微环境（TME）的一些独特特征，如缺氧、低 pH 值和升高的间质流体压力，导致癌细胞对大多数治疗方法产生耐药性。由于细菌具有内在的肿瘤趋向性、高迁移性以及在有利的 TME 中快速定植的能力，它们越来越被认为是一种靶向肿瘤治疗的方法。与使用肽、适体和其他生物分子的其他纳米策略相比，肿瘤靶向细菌受肿瘤细胞和微环境的影响较小。相反，缺氧的 TME 非常有利于兼性厌氧菌和专性厌氧菌的生长。活细菌可以进一步与抗癌药物和纳米材料结合，以增加后者在肿瘤中的靶向递送和积累。此外，厌氧和兼性厌氧菌也与其他抗癌疗法结合使用，以增强治疗效果。在这篇综述中，我们总结了使用细菌进行靶向肿瘤治疗的应用和优势（方案 1），以帮助设计新型智能药物递送系统。还讨论了肿瘤靶向细菌纳米载体的当前挑战和未来前景。
