Development of a Tacrolimus-loaded carboxymethyl chitosan scaffold as an effective 3D-printed wound dressing

Infection and lack of angiogenesis are considered to be the main factors slowing the healing process in chronic wounds. To address these challenges, bioactive, multi-functional wound dressings have received a lot of attention. A 3D-printed carboxymethyl chitosan scaffold loaded with Tacrolimus (TAC-CMC) was introduced and tested as a potential bioactive dressing for chronic wound healing. Following topographical and physical characterization of the wound dressings, the release profile of Tacrolimus from the TAC-CMC scaffold was investigated. In vitro evaluation revealed that both carboxymethyl chitosan scaffold (CMC) and TAC-CMC scaffolds were biocompatible, but only TAC-CMC causing an increase in the secretion of vascular endothelial growth factor (VEGF) from fibroblasts. Disk diffusion test of the fabricated scaffolds demonstrated a significant antibacterial activity of TAC-CMC scaffold against both E. Coli and S. aureus as Gram negative and positive bacteria, respectively. The in vivo assessments of the bare and bioactive wound dressings have revealed that 7 days post-wounding, wounds treated with the TAC-CMC resulted in a 90.4 ± 2.4% closure rate which was significantly faster than those in the positive control (Comfeel plus®). The histopathological evaluation of the treated and non-treated wounds proved the efficacy of TAC-CMC scaffold in improving angiogenesis, epidermal regeneration, fibroblasts proliferation, and inflammatory responses.