Single-cell nanoencapsulation enables fabrication of probiotics-loaded hydrogel dressing with improved wound healing efficacy in vivo

Purpose: Loading pharmaceutical adjuvants into hydrogel dressing can enhance wound healing efficacy. Herein, we installed nanocoated-probiotics into hydrogel dressings for improved wound healing efficacy. Methods: The single-cell nanoencapsulation (SCNE) technique using tannic acid-Fe(III) complex was utilized to coat the individual probiotics. Two model probiotics, Lactobacillus plantarum and Lactobacillus brevis, were selected owing to their positive effects on skin health. Results: Hydrogel dressings loaded with probiotics were composed of mannitol and polyvinyl alcohol (PVA) at a weight ratio of 2:10, exhibiting superior swelling capacity and solid elastic properties. The thin coated layers on the individual probiotics demonstrated enhanced protection of bacterial viability against freeze-thaw cycles, which is crucial for fabricating probiotics-loaded hydrogel dressings. In vivo transdermal wound healing tests revealed that the hydrogel dressings loaded with coated probiotics showed superior wound healing efficacy compared to those loaded with non-coated probiotics. Conclusion: Our results not only contribute to the improvement of wound dressing formulations, but also inspire to development of new dosage forms with coated functional microorganisms using the SCNE technique.