An animal study of a novel tri-layer wound dressing material -: non-woven fabric grafted with N-isopropyl acrylamide and gelatin

A novel method of preparation of easily stripped-off temporary wound dressing material is described. A tri-layer membrane system for artificial skin is prepared in this study. In this process, the N-isopropyl acrylamide monomer is successfully grafted on the non-woven fabric by co-polymerization. It is initiated by plasma to activate the surface of the non-woven cloth. N-isopropyl acrylamide is then grafted onto the surface of the non-woven cloth by gamma-ray irradiation. The last, but the most important, layer of a bovine gelatin with glycosaminoglycans (chondroitin-6-sulfate) is grafted by UV light, which serves as a matrix for the infiltration of fibroblasts, macrophages, lymphocytes, and capillaries derived from the wound bed. The goal in this work is to provide a non-antigenic membrane closely resembling dermis in its anatomic structure and chemical composition, which would act as a scaffold inducing the synthesis of a new dermis. The following describes the construction and animal testing of this artificial skin when there is extensive damage. In the experiment, the specimens are divided into four groups: (1) control group without dressing material; (2) non-woven fabric; (3) non-woven fabric grafted with NIPAAm; and (4) non-woven fabric grafted with NIPAAm, bovine gelatin, and glycosaminoglycans from bottom to top in sequence. Six weeks after the operation both, the control and non-woven fabric groups stayed in the proliferative phase where no epidermis or dermis structure could be traced in the section; however, the third group had healed completely in the maturation phase. The wound site had been totally recovered with normal dermis and epidermis structure around, but with the dressing material still staying on the wound site. In the group of the non-woven fabric grafted with NIPAAm, gelatin, and glycosaminoglycans, the wound had recovered to the final stage of maturation phase. The wound site had totally recovered at the 4th week post operation. The dressing material of the group fell off automatically from the wound site without any damage to the skin after recovery. We believe the dressing material will have a great potential in medical application in the near future. (C) 2000 Elsevier Science S.A. All rights reserved.