ABSTRACT
Chronic refractory wounds have been a challenge for clinical treatment because of their diverse causative factors and complex pathological processes, long healing times, and high treatment costs. The microenvironment of the wound surface includes the external microenvironment of the periwound surface, the internal microenvironment of the wound surface, and subsurface physiological structures. Research on clinical treatment strategies based on the microenvironment of chronic refractory wounds continues to innovate and make progress. Hydrogels have the advantages of high-water content, adjustable performance, good biocompatibility, and similarity to extracellular matrix. The ability of hydrogels to load drugs and their modification to confer excellent tissue adhesion, antibacterial, antioxidant, and modulation of inflammatory factor expression can be used to achieve a multi-factor response and modulation of the physical, chemical, and biological aspects of the trauma microenvironment. Therefore, hydrogels have outstanding advantages and clinical application prospects in the repair of chronic, difficult-to-heal wounds. In this review paper, the characteristics and etiology of chronic refractory wounds were introduced, and the classification of microenvironment-responsive hydrogels for chronic refractory wounds and their application in the repair of refractory wounds were reviewed. Besides, the shortcomings of current hydrogels were discussed, and an outlook was proposed.