Advances in drug delivery systems based on liposome-composite hydrogel microspheres

Research on liposome-composite hydrogel microspheres (LHMs) drug delivery systems, primarily composed of drugs, liposomes, and hydrogels, has garnered growing scientific interest. LHMs exhibit biosafety, modifiability, a wide range of loaded drug categories (water-soluble or fat-soluble), controlled and sustainable drug release capability, and specific cell-targeted performance, which compensate for the shortcomings of conventional drug delivery methods due to the complementary advantages of liposome and hydrogel microspheres. In this review, we systematically analyze the existing literature on LHMs and provide a comprehensive overview of their preparation methods. Specifically, we detail the fabrication techniques for liposomes, including thin-film hydration, solvent injection, multiple emulsion, reverse-phase evaporation, gradient, freeze-drying, supercritical fluid, and microfluidic approaches as well as methodologies for LHMs, such as microfluidics, electrospraying, 3D printing, reverse-phase microemulsion, and physical adsorption. We also summarize the optimization approaches for LHMs properties when combining liposomes and hydrogel microspheres. Finally, we present the applications and challenges of LHMs. We hope that this review will foster more insights into LHMs in drug delivery fields.