الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Diabetes mellitus is a serious problem of public health worldwide and it tends to increase in
numbers, mainly in the developed countries. Beside, it is a common disorder associated with
an increased morbidity and mortality and can be defined as a group of metabolic diseases
characterized by chronic hyperglycemia due to defective insulin secretion, insulin action, or
both, resulting in impaired carbohydrate, lipid, and protein metabolism (Akah et al.,
2009).One of the most serious and debilitating complications of diabetes is the development
of chronic non-healing foot ulcerations.
Diabetes is a condition known even in its early stages to impair the normal course of
wound healing, thus leading to chronic wounds. The wound-healing impairment in diabetes
can be attributed to several factors including inadequate blood supply, decreased proliferative
potential of fibroblasts, and decreased inflammatory changes (Sharma et al., 2006).
Wound healing is a dynamic, interactive process involving soluble mediators, blood
cells, extracellular matrix, and parenchymal cells. The healing has three phases –
inflammation, tissue formation, and tissue remodeling, which overlap in time (Singer and
Clark, 1999).
At the cellular level, each phase is directed by the coordinated interaction of several
types of cells, including inflammatory cells and native skin cells such as fibroblasts,
keratinocytes and vascular endothelial cells. At the molecular level, cytokines regulate
inflammatory cells during the early stages of wound healing, and throughout the process
polypeptide growth factors play dominant roles in the regulation of the proliferation and
differentiation of native skin cells and the synthesis of extracellular matrix (Martin, 1997;Goldman, 2004). Chitosan is a natural nontoxic cationic biopolymer produced by the deacetylation of chitin (a major component of the shells of crustaceans such as crab, shrimp, and crawfish). Currently, chitosan has received considerable attention for its commercial applications in the
biomedical, food, and chemical industries (Kurita, 1998).
Chitosan possess the characteristics favorable for promoting rapid dermal
regeneration and accelerated wound healing. Biochemical and histological changes of Chapter I Introduction and Review of Literature Chitosan in wound healing has been reviewed by (Azad et al., 2004) as chitosan provides a
non-protein matrix for three dimensions tissue growth and activates macrophages for tumoricidal activity. It stimulates cell proliferation and histoarchitectural tissue organization.
It will gradually depolymerize to release N-acetyl-b-Dglucosamine, which initiates fibroblast proliferation and helps in ordered collagen deposition, stimulating increased level of natural
hyaluronic acid synthesis at the wound site. Okamoto et al., (1995); Vinsova and Vavrikova (2011) had mentioned that,chitosan helps in faster wound healing and scar prevention;chitosan derivatives have also an antimicrobial, antitumor and antioxidant activities.
The aim of the present work is to compare the wound healing stages in healthy and diabetic rats. Besides, the effect of topical application of chitosan solution on full thickness
open skin wound during regeneration process of healthy and diabetic rats to evaluate its efficacy as an accelerator in wound repair will be mentioned.