Inhibition of E-Selectin by Selectively deSulfated Heparin through Chitosan Microspheres Impregnated Collagen Scaffold

Abstract

Wound healing is a collaborative process involving a variety of cellular and matrix components which need to interact continually towards a common goal. Growth factors and cytokines are two distinct categories of signaling proteins that modulate wound healing at molecular and cellular levels. Cells synthesize different proteins for their proliferation and migration which are controlled in a phased manner. Chronic wounds lead to changes in local regulation of inflammation and trigger the adverse effects. It is necessary to control the inflammation through proper agents. Heparin has an anti-inflammatory property when it is selectively desulfated, in dose dependent manner by blocking the extravasation of leukocytes to the endothelium of an injured site. This partially desulfated heparin (DSH) was entrapped in chitosan microspheres developed by novel water in oil emulsion technique and impregnated in collagen scaffold for its controlled delivery. Hence, structurally modified heparins which possess less anti coagulant activity and more anti inflammatory activity were investigated. The concentration of 2, 3 DSH to be used to serve as an anti inflammatory agent was determined using clotting assay and static adhesion of leukocytes to endothelium. The down regulation of E-selectin was assessed by western blot and immunocytochemistry using monoclonal antibodies. The delivery system for controlled release of 2, 3 DSH was designed using chitosan microspheres and collagen as scaffold. The scaffold was characterized for its physicochemical and biological properties. Wound healing studies in rat burn wound model exhibited a faster healing rate in treated group when compared to that of controls. In vitro and in vivo studies support the efficacy of the modified heparin namely 2, 3 DSH as a therapeutic agent to regulate inflammation.