Modulation of Biophysical Cues in Nature Inspired Patterning of Porous Silk Fibroin Scaffold for Replenishable Controlled Drug Delivery.

In our daily lives, cuts and wounds are unavoidable. while they are generally minor, sometimes they do turn serious. While a sticking plaster might be enough in most cases, critical situations like surgical wounds, lacerations, gunshot wounds, accidental skin injuries, diabetic wounds, and other cutaneous deep cuts may require implants and simultaneous medications for healing. From the biophysical standpoint one of the least explored aspects to surmount these hurdles is the internal force-based physical surface stimulus crucial for cellular sensing at the time of wound repair. With more people needing medical attention for wound healing, smart patches will be an integral part of the future generation of wound treatment. We report fabrication of a novel biomimetically patterned silk fibroin porous scaffold with an approach to ampicillin loading and replenishment by joining a polytetrafluoroethylene (PTFE) catheter attached 18G butterfly intravenous infusion needle at the bottom of the substrates. In vitro swelling study reveals that the patterned substrates show less swelling compared to that of the other variants and consequently less in vitro degradation. The ampicillin release patterns from the scaffolds follows the Korsemeyer-Peppas model depicting surface hydrophobicity mediated non-fickian first-order anomalous controlled release. The scaffolds show remarkable antibacterial efficacy against Methicillin-Resistant Staphylococcus aureus (MRSA) and Escherichia coli. Four distinct cell-matrix adhesion regimes were investigated for the fibroblasts to eventually form cell sheets all over the hierarchical surface structures. The fluorescence images after DAPI and FDA staining clearly demonstrates that the patterned surface to be superior to its other variants. A comparative study among molecular expressions of collagen I, vinculin, and vimentin using immunofluorescence, substantiated the patterned surface to be superior to others. The work report potential development of a deep cutaneous wound healing drug replenishable implant with biophysical cues capable of controlling fibroblast behavior and release kinetics of ampicillin. This article is protected by copyright. All rights reserved.