While reloadable drug delivery platforms are highly prized for the treatment of a broad spectrum of diseases, the gel-gel interface between
hydrogels hinders the
intergel diffusive transport of drugs and thus limits the application of
hydrogels as reloadable depots. Here, this study reports the circumvention of this barrier by employing a self-healing
hydrogel prepared from N-carboxyethyl
chitosan and
sodium alginate dialdehyde, which are cross-linked via a reversible
Schiff base linkage. The
injectable and bioadhesive
hydrogel shows a rapid gelation time of 47 s. The dynamic self-healing process enables the efficient diffusive transport of
carbon quantum dots (C-dots) into an adjacent
hydrogel, and thus, the C-dots can be used to scavenge
reactive oxygen species from a remote
inflammation site. Specifically, the diffusive transport of the C-dots in the self-healing
hydrogel after three sequential reloading steps is sevenfold greater than that in the non-self-healing counterpart. In vivo,
hematoxylin and
eosin staining of the murine skin at the injection site shows no apparent symptoms of
inflammation in the group treated with the reloadable self-healing
hydrogel. The current strategy represents a promising and straightforward route for the design of a reloadable drug delivery system for future use in clinical application.