A double-layer scaffold composed of 3D bioprinted layer of granulocyte-colony stimulating factor and electrospun nanofibers of abietic acid for full thickness skin repair.

Wound healing is a multifaceted and dynamic process, and any interruption in this process presents a considerable challenge to healthcare. Advanced wound dressings are essential in improving healing outcomes by offering protection, facilitating tissue regeneration, and preventing infections. This study centers on the development of a biopolymer-based two-layer wound dressing that integrates granulocyte-colony stimulating factor (G-CSF) for tissue regeneration and abietic acid for its anti-inflammatory properties. The lower layer was 3D-printed and composed of sodium alginate, polyacrylamide, sodium CMC and different concentrations of hyaluronic acid infused with G-CSF, while the upper layer was formed from electrospun polyacrylamide, polyvinyl alcohol (PVA) and hyaluronic acid nanofibers containing abietic acid. Different ratios of polyacrylamide to hyaluronic acid were assessed to enhance mechanical properties, swelling behavior, biodegradability, and the proliferation of fibroblast cells (L929). The optimized formulation demonstrated a swelling ratio of 93% and a biodegradation rate of 94%, reflecting favorable hydration and degradation properties appropriate for wound environments. Results from the MTT assay indicated a 168% increase in cell viability after 72 h with the application of the double-layered dressing. An in vivo assessment utilizing a 14-day rat wound model showed improved angiogenic potential and 94% wound closure by day 15. Histomorphological analysis further validated complete re-epithelialization, organized collagen deposition, and full regeneration of skin appendages, signifying effective tissue remodeling. This dual-layer approach enhanced wound healing by integrating structural support, controlled release of bioactive agents, and improved cellular response, thus offering a promising strategy for advanced wound care.