Acceleration of wound healing in diabetic rats by layered hydrogel dressing

In this study, a novel layered hydrogel composing of alginate (AL), chitosan (CS), and poly(gamma-glutamic acid) (PGA) was prepared. The resulting hydrogel was characterized, including the swelling ratio, water vapor transmission rate, the release of Ca2+ and blood coagulation activity. In vitro evaluation of cell migration and proliferation were carried out on electric cell-substrate impedance sensing (ECIS). Effect of the hydrogels on wound healing was examined in type 1 diabetic rat model induced by streptozotoxin (STZ). After grafting to full-thickness wounds in diabetic rats, AL-CS-PGA exhibited higher rate of wound healing than conventional AL hydrogels. Epithelialization and collagen deposition were examined histologically. Hydroxyproline levels also were assessed in the wound skin. The results indicated AL-CS-PGA treated wounds showed increased collagen regeneration and epithelialization. Therefore AL-CS-PGA can improve wound healing of diabetic rat models comparing to conventional AL wound dressing. (C) 2012 Elsevier Ltd. All rights reserved.