Utilization of electrospun silk fibroin fibers as scaffolding material for skin regeneration

Abstract

In this research, the effects of electrospinning parameters [silk fibroin (SF) solution concentrations and applied voltages] on the morphology and diameters of electrospun SF fibers from Bombyx mori (B.mori) were investigated. The range of SF solution concentration studied was from 42 % (w/v) to 52% (w/v) and the range of applied voltage studied was from 15 kV to 30 kV. The results indicated that the optimal condition for fabrication of the uniform SF nanofibers without beads was 50% (w/v) SF solution with an applied voltage of 25 kV over a collection distance of 15 cm using a gauge 20 needle. The morphology, thermal properties, and surface characteristic of as-prepared and hyaluronic acid (HA) coating electrospun silk fibroin were investigated by SEM, TGA, and ATR-IR, respectively. Potential use of the electrospun SF fiber mats as scaffolding materials for skin regeneration was evaluated in comparison with HA-coated electrospun SF fiber mats and solution-cast SF films. The cytotoxicity evaluation of these materials was carried out based on the indirect cytotoxicity evaluation procedure using a mouse fibroblasts (L929), while the attachment and the proliferation evaluation was carried out using human foreskin fibroblasts (HFF; primary cells) and immortalized human keratinocytes (HaCaT). It was observed that all of the fibrous and the film scaffolds posed no threat to the cells and HA-coated electrospun SF fiber mats supported both the attachment and the outgrowth of cells better than the other types of the scaffolds at initial stage of culture, because HA is a major constituent of the extracellular matrix (ECM). Moreover, electrospun SF fiber mats provided a higher level of surface area-to-volume ratio and porosity for cells to attach. Therefore, electrospun SF fiber mats with or without HA coating exhibited a reasonably good potential for wound dressing and/or skin scaffolding applications.