Multifunctional biopolymer hydrogels containing carrier-free
bioactive-loaded microcapsules for S. aureus-infected wound healing
Abstract
Wound healing dressings are designed to accelerate the regeneration of
skin tissue and return it to its normal physiological activity. Several
factors must be considered when designing wound healing dressings,
including their mechanical, barrier, adhesive, degradation, and safety
properties, as well as their ability to promote tissue regeneration. In
this study, natural active small molecule anisaldehyde-tannic acid-zinc
ion (AA-TA-Zn 2+) microcapsules by self-assembly and
coordination strategies without any carrier or surfactant are
constructed, integrating good antimicrobial, antioxidant,
anti-inflammatory activities, sustained release, and pH responsiveness.
Subsequently, natural small-molecule microcapsules are used to
functionalize chitosan-gelatin (CG)-based hydrogels, endowing them with
good injectability, adhesion, self-healing, antibacterial, antioxidant,
and anti-inflammatory properties. This multifunctional hydrogel is
primarily formed through a fourfold cross-linking mechanism involving
Schiff base formation, hydrogen bonding, ionic interactions, and
electrostatic forces, without the involvement of any chemical synthesis
reactions. The microcapsules-loaded hydrogels are shown to kill bacteria
around the wound, reduce oxidative stress damage, inhibit the
proliferation of inflammatory cells, facilitate the reconstruction of
the vascular network, promote the orderly deposition of collagen,
facilitate the reconstruction of damaged tissues, clean the
micro-environment of the wound areas, and recover the normal immune
system, thereby hastening the repair and healing of S.
aureus-infected wounds. These advanced multifunctional dressings may
therefore have great potential for application in the biomedical field.