Phase-separated hydrogels for advanced biomedical engineering: From material design to applications

Hydrogels are extensively employed in wound healing, drug delivery, and the manufacturing of medical devices due to their distinctive physical and chemical properties and biocompatibility. The development of manufacturing platforms such as bioprinting and microfluidics has further advanced the clinical application of hydrogels, improving precision, efficiency, and cost-effectiveness. However, the constrained mechanical and biological properties of hydrogels have hindered their broader use, prompting research into new modification methods. Phase separation is one promising way to address this problem. Here, the mechanisms of phase separation and the recent progress in the fabrication of phase-separated hydrogels is reviewed to elucidate the relationship between hydrogel properties and phase separation. This review subsequently highlights four main biomedical applications of phase-separated hydrogels, including tissue engineering, drug delivery, biosensing, and bioprinting. Finally, the challenges and future prospects of phase-separated hydrogels in the biomedical field are discussed, offering new insights for further improvements and exploration of novel directions.