Biocompatibility and angiogenesis evaluations of biomedical grade chitosan derivative films in rabbits
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Date
2009
Authors
Saifuddin, Siti Nazmin
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Abstract
Chitosan is composed of glucosamine and N-acetylglucosamine, which are constituents of mammalian tissues. Chitosan is a non-toxic, biocompatible, and biodegradable polymer and has been proposed for use as a topical agent in tissue repair. SIRIM Berhad has developed three new types of chitosan derivative films which are N-carboxymethylchitosan (N-CMC), N,O-carboxymethylchitosan (NO-CMC) and Oligo Chito. As these films are novel inventions, this study was conducted to evaluate the biocompatibility and angiogenesis of these three types of chitosan derivative films on rabbits using implantation and partial-thickness wound models. In implant model, empty pockets served as control and in partial-thickness wound model, Aquacel® (commercial dressing), served as control. Histological examination revealed that inflammations elicited in all chitosan derivative implants were higher than that observed in control due to the presence of the implants in the tissue. However, these reactions were organized and did not deviate from the course of inflammation associated with healing process as observed in partial-thickness wound model, rendering these materials biocompatible. Macroscopic evaluations of the dressings and wounds demonstrated that all three types of chitosan derivative films, namely O-C, N-CMC and NO-CMC, possess the necessary basic attributes to be employed as wound dressing comparable to the commercial dressing (Aquacel®). In angiogenesis evaluation, results of the microvessel densities demonstrated that the test materials were able to promote the angiogenesis as higher densities were observed in chitosan derivatives compared to control in implant model and comparable to Aquacel® in partial-thickness wound model. All chitosan derivative implants were also able to promote the endogenous expression of VEGF in both models. Relationship between VEGF expressions of the chitosan derivatives and their microvessel densities and fibrous capsule thickness in implant model showed positive correlations except for NO-CMC which showed no correlation in microvessel density. No correlation was observed between VEGF expression and microvessel densities and granulation index in all chitosan derivatives-treated wounds except for Aquacel® and O-C in granulation index. These signify that all chitosan derivatives do promote the angiogenesis and this process may be enhanced by VEGF or other angiogenic factors.
Description
Master
Keywords
Biological Science , Biomedical grade chitosan , Rabbits