PREPARATION an‎d EVALUATION OF CROSS LINKED CHITOSANPOLYURETHANE MESH IN TISSUE REPAIR IN SHEEP

In the present study, an interpenetrating polymer network (cross-linked chitosan-polyurethane mix) was successfully prepared. It was found that the mixing of 70% chitosan and 30% polyurethane gave the best results as far as the mechanical properties of the network are concerned. Toxicological evaluation of the network was done in 15 rabbits, and it was found to be pathologically nontoxic.The possible effects of the network on the liver, kidneys, and skeletal muscles of sheep with clean or infected open wounds were studied through the measurement of plasma aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, and acid phosphatase. In sheep with clean open wounds that were implanted with the network, the levels of the enzymes were 11.04 ± 0.54;30.83 ± 1.20; 36.37 ± 1.52; and 5.52 ± 0.37, respectively. In sheep with contaminated wounds, the levels of the enzymes were 11.29 ± 0.30; 38.58 ± 1.16;38.20 ± 1.21, and 6.31 ± 0.46, respectively. Statistically significant differences were not encountered in the values of alanine aminotransferase, alkaline phosphatase, and acid phosphatase in sheep with clean wounds and those with contaminated wounds. However, the level of aspartate aminotransferase was higher significantly (P 0.01) in sheep with contaminated wounds than in sheep with clean wounds. Histologically, the healing of the clean and contaminated open wounds proceeded through the same processes as described in the literature. Bacterial infection was not observed in any of the wounds that were implanted with the network