Cellulose nanofiber-reinforced antimicrobial and antioxidant multifunctional hydrogel with self-healing, adhesion for enhanced wound healing

Abstract

Current conventional wound dressings used for wound healing are often characterized by restricted bioactivity and devoid of multifunctionality resulting in suboptimal treatment and prolonged healing. Despite recent advances, the simultaneous incorporation of excellent flexibility, good mechanical performance, self-healing, bioactivity, and adhesion properties into the dressings without complicating their efficacy while maintaining simple synthesis remains a grand challenge. Herein, we effectively synthesized hybrid hydrogels of cellulose nanofiber (CNF), polyvinyl alcohol (PVA), and curcumin-modified silver nanoparticles (cAg) through a one-step synthesis method based on hydrogen bonds, dynamic boronic ester bonds, and coordinate covalent bonds. A flexible high mechanical strength (tensile stress (231 kPa) and compressive stress (1.23 MPa), self-healing, adhesive, yet highly antioxidant and antimicrobial hydrogel (with improved activity against C. albicans, S. aureus, and E. coli) is successfully obtained. Concentric structure of the micropores endows the hydrogels, good biodegradability, and sustained drug release of silver and curcumin. More remarkably, the designed hydrogel dressings not only significantly enhance cell viability (over 98 %) and cell proliferation but also promote angiogenesis, re-epithelialization, and deposition of collagen, all of which signal wound closure and substantiate the therapeutic effect of CNF/PB/cAg hydrogels in chronic wounds. These findings open up new perspectives for the design of wound healing hydrogels and beyond.