Silver-Nanoparticle-Entrapped Soft GelMA Gels as Prospective Scaffolds for Wound Healing

Gelatin-based hydrogels have received particular attention for tissue-engineering applications given their biocompatibility, ease of tuning their physical properties through chemical modifications, and incorporation of antibacterial activity. While several studies have focused on the detailed quantification of biomechanical properties of these gels, considerably less attention has been paid to understanding how adhesivity of these gels impacts single as well as collective cell migration, which directly determines the efficacy of wound healing. In this study, we address this question by quantifying fibroblast motility and antibacterial activity of silver nanoparticle (AgNP)-entrapped methacrylated gelatin (GelMA) hydrogels. Using 5 and 15% GelMA soft gels cross-linked with 1 min UV exposure, we first show that cells spread more and migrate faster on 15% GelMA gels. Next, we show that ∼10 nm AgNPs entrapped in 15% GelMA gels get released over a time-scale greater than 72 h and exhibit antibacterial activity against both Gram-positive and Gram-negative bacteria at concentrations nontoxic to cells. Finally, using a polydimethylsiloxane (PDMS) device for simulating wound healing, we show that closure of ∼800 μm gaps on GelMA gels is significantly faster compared with other conditions. Together, our findings illustrate the potential of AgNP-entrapped soft GelMA gels as scaffolds for achieving accelerated wound healing of deep dermal wounds by enabling fast fibroblast migration and minimization of microbial infections.