Fast-crosslinking, shape-adaptable, conductive, and dual-antibacterial hydrogels based on oxidized dextran and polyvinyl alcohol-ε-polylysine for infected skeletal muscle healing

Irregular infected skeletal muscle injuries or defects has become a major global public health issue. Muscle tissue engineering provides a novel methodology to tackle this issue, however, often limited by shape-adaptable and antibacterial performances of scaffolds as well as time-consuming construction period. In this work, we propose a hydrogel scaffold matching physicochemical properties of skeletal muscle with super-stretchability (elongation >4000 %), excellent shape-adaptability (> 99 % of shape recovery), degradability (degraded >98 % after 20 days), fast self-healing ability, injectability, electrical conductivity, and rapid gelation time (< 5 s) based on aldehyde dextran (ODEX), peptide ε-polylysine (EPL) grafted onto polyvinyl alcohol (PVA; PVA-EPL), boronic acid (BA), and hydroxylated multi-walled carbon nanotubes (MWCNTs). Hydrogel scaffold was developed by Schiff-base and boronate ester crosslinkings after mixing with ODEX, PVA-EPL, BA, and MWCNTs aqueous solutions. The resultant hydrogel demonstrates biological functions including excellent antibacterial activities with the aid of antibacterial peptide and near infrared red light, good anti-oxidant properties, anti-inflammatory abilities, and myogenic differentiation promoting effects in vitro. In vivo infected skeletal muscle tissue repair of rats further shows outstanding pro-repairing effects and antibacterial activities. This well-designed hydrogel platform could be served as a candidate for irregular infected skeletal muscle tissue engineering scaffolds.