Development of electrospun chitosan scaffold for wound dressing application

Wound dressing is one of the most promising medical applications for chitosan, due to its adhesive nature, together with some biological properties including bacteriostatic and fungistatic properties that help in faster wound healing.
In this work we propose a chitosan biomimetic scaffolds and methods for modulating their intrinsic properties such as rigidity, elasticity, resistance to mechanical stress, porosity, biodegradation and absorbance of exudates. Therefore, the chitosan scaffold comprising at least two fused layers, wherein the advantage of a first fused layer composed of a chitosan electrospun nanofiber membrane are oxygen-permeability, high porosity, variable pore-size distribution, high surface to volume ratio, and most importantly, morphological similarity to natural extracellular matrix in skin, which promote cell adhesion migration and proliferation. The advantages of a second fused layer comprising a porous chitosan support layer are improving mechanical property, good absorption capacities to remove excess exudates and good water and gas exchange. Moreover, the scaffold was characterized by (i) a good adhesion between the porous and nanofiber layers, (ii) a tuneable porosity of the nanofiber layer by tuning the distance between the nanofibers, (iii) a stable nanofibers and porous morphology even when immersed in water. Finally, the scaffolds have shown tremendous promise as a wound dressing, in tissue engineering. The three main human cell types fibroblasts, endothelial cells and keratinocytes was cultured in vitro on electrospun nanofibers scaffold. Properties of electrospun chitosan scaffold and chitosan sponges obtained by lyophilization were also compared in vivo, in order to evaluate importance of the 3D-architecture of the biomaterial.