Polyvinyl Alcohol Based Composite Sponges for Wound Delivery of Deferoxamine: Impacts of Polymeric Composition and Freeze-Thaw Cycles

Abstract

Porous sponges of polyvinyl alcohol (PVA) can provide moist environment, protect wound from microbial attack, absorb excess exudates, exchanges oxygen and water vapor, and deliver therapeutic agents to the wound site. However, more information should be gained about comparing properties of crosslinked and non-crosslinked PVA sponges and the impacts of adding other biopolymers such as sodium alginate (ALG) and sodium carboxy methyl cellulose (CMC) on the wound dressing properties and drug release from these composite sponges. Here we have prepared and characterized PVA composite sponges loaded with deferoxamine (DFO), a drug with prominent wound-healing effects, to manage exudative chronic wounds. The impacts of crosslinking by freeze thaw cycles and adding CMC or ALG to PVA sponges were evaluated on morphology, mechanical strength, crystallinity, porosity, fluid uptake, water vapor transmission rate, water vapor loss, pH, blood compatibility, and controlling drug release. The produced sponges differed in crystallinity of PVA, pore shape, size, and interconnectivity. Crosslinked composite sponges showed better porosity than non-crosslinked ones and had higher porosity (>80%) with interconnected macropores in the appropriate size range for cell attachment. All sponges were hemocompatible with less than 1% hemolysis and had good physical integrity and flexible texture. The water handling properties were also affected by crosslinking. Although all prepared sponges showed high water absorption in the range of 450–650% within 6 h, the crosslinked sponges showed slower water uptake than non-crosslinked samples. Prepared sponges could control DFO release with 60% cumulative release over 24 and sponge composition and crosslinking influenced DFO release.