A novel injectable and self-biodegradable poly(aspartic acid) hydrogel

Severely chronic dermal wounds with irregular rupture shapes or even cavities are calling for injectable and self-biodegradable wound dressings for skin lesion with complex contours remain a great challenge. Here, we report an injectable, self-biodegradable poly(aspartic acid)-l-poly(aspartyl hydrazide) (PASP-l-PAHy) hydrogel to address these issues. The starting materials were cheap, and the new strategy for fabrication of self-biodegradable poly(aspartic acid) based hydrogel was facile, efficient, mild and environmentally friendly, which is consistent with the concept of green chemistry. The hydrogel possesses the comprehensive merits of injectability, self-biodegradability, shape-adaptability, transparence, biocompatibility, and adhesion, and shows specific autolytic biodegradation. The hydrogel was generated by in-situ gelation of poly(aspartic acid) (PASP) and poly(aspartyl hydrazide) (PAHy) polymers based on dual chemical (amide bond) and physical (hydrogen bond and ionic bond) crosslinks. The acceleration of wound healing could be observed in a rat skin full-thickness wound model for repairing skin tissue defects via hydrogel injection and autolytic biodegradation, highlighting great potential applications in wound dressing for the irregular dermal lesions without secondary skin damage. The injectable and self-biodegradable hydrogel augments formation of blood vessels and mature granulation tissue, thus enabling faster skin tissue restoration outcomes.