Multi-drug sequential release systems: Construction and application for synergistic tumor treatment

In tumor treatment, the sequence and timing of drug action have a large influence on therapeutic efficacy. Multi-drug sequential release systems (MDSRS) enable the sequential and/or on-demand release of multiple drugs following the single administration of a therapeutic agent. Several researchers have explored MDSRS, providing fresh strategies for synergistic cancer therapy. This review article first introduces the main characteristics of MDSRS. It then elaborates on the design principles of MDSRS. Subsequently, it summarizes the various structures of carriers used for constructing MDSRS, including core-shell structure, Layer-by-layer structure, Janus structure and hydrogel. Next, through specific examples, the article emphasizes the application of MDSRS in cancer treatment, focusing on their role in remodeling the tumor microenvironment (TME) and enhancing therapeutic effects through multiple mechanisms. Finally, the article discusses the current limitations and challenges of these systems and proposes potential future solutions. Overall, this review underscores the importance of the sequence and timing of drug therapy in cancer treatment, providing valuable theoretical and technical guidance for pharmaceutical research.