Utilizing dextran to improve hemocompatibility of antimicrobial wound dressings with embedded quaternary ammonium salts

Dextran, a polysaccharide with interfering effects on coagulation hemeostasis was utilized to compensate the hostile effects of quaternary ammonium salts (QAS) embed in the backbone of a wound dressing membrane as an antimicrobial agent. Despite the high antimicrobial efficiency of QAS, their adverse hemolytic effect on red blood cells is a challenging problem for using them as an active antiseptic agent in wound dressings. To this end, wound dressings made through the sol-gel hydrolysis and polycondensation reaction of a methoxysilane-functionalized quaternary ammonium compound (Si-RQ) and a methoxysilane terminated polyurethane prepolymer (Si-PPU), at different compositions, were surface modified with dextran. The final dressings were then subjected to various biological and physico-mechanical assays. The low hemolysis rate and prolonged clot formation on dextran-modified dressings confirmed their excellent hemocompatibility. Meanwhile, the optimized dressings preserved their excellent antimicrobial activity against both Gram-positive and Gram-negative bacteria and a fungal strain up to 100% killing efficiency. In addition, they exhibited very good cytocompatibility since the fibroblast cells could grow and proliferate efficiently on their surface. The recorded results confirmed the effectiveness of surface anchored dextran for regulation of hemocompatibility of QAS containing wound dressings without deterioration of their basic physical and biological properties. (C) 2019 Elsevier B.V. All rights reserved.