Bacterial-based drug delivery systems: A new way to combat infectious disease

Recent advances in targeted drug delivery system (DDS) have generated high expectations for the treatment of various diseases. The main advantages of DDS are precise and efficient drug delivery, increased concentration and effectiveness of drugs at the site of action, minimal systemic distribution of harmful drugs, and reduced side effects. The choice of DDS often depends on the specific disease being treated, with common options including liposomes, nanoparticles, microspheres, and various biomaterials such as cell lines and microbial components. DDS is most prominent in cancer therapy, where challenges such as limited access to tumor tissues and drug-inactivating environments complicate treatment. However, in recent decades, the emergence of antibiotic resistance and the therapeutic difficulties associated with chronic and intracellular bacterial infections have made infectious diseases a key focus for DDS development. Initial DDS approaches for bacterial infections were based on nano-derivatives. During more advanced stages of research, even the bacteria themselves became vehicles for DDS focused on microbial infections. All aspects of the bacteria- cell lysates, envelopes, derived vesicles, spores, and so forth-have been evaluated as DDS. This form of DDS does not only promote the immediate treatment of an infection but also expedites recovery times through immunological manipulation. Despite these advancements, there remains a lack of cohesive data regarding bacterial DDS in the treatment of infectious diseases. Therefore, this review aims to provide an overview of the various types of bacterial DDS, their applications, advancements, and the challenges they face.