http://www.lifesciencesite.com ) 2 2013;10( Life Science Journal 1313 Assessment to the Effects of Low Power Diode Laser on Wound Healing in Diabetic Rats Ahmed.H.Osman 1 ,Mahmoud .M. Kamel 2 , Mohamed.H.Wahdan 3 , Mahmoud Al-gazaly 4 Departments of 1 Pathology , 2 Clinical Pathology, 3 Anatomy and 4 Physics , Faulty of Medicine, Taif University 2 National Cancer Institute, Cairo University, Egypt. ahosman2007@hotmail.com Abstract: Objective: Evaluation of the effect of low level laser therapy (LLLT) using diode laser 808 nm on wound healing in diabetic rats as experimental animal model. Back ground data: Delayed wound healing is reported by several medical care units as changing cases. One of the causes for chronic wounds and delayed wound healing is diabetes which sometime associated with suppuration, gangrene and may be ended by amputation. This is encountered in different medical specialities. Methods: 40 male albino rats, each weighed 200-220 gm. Diabetes was chemically induced using streptozotocin, 40 mg/kg, dissolved in citrate buffer solution (pH 4.3) and administered as tail vein injection in all experimental rats groups expect control group . Seven days after streptozotocin injection, blood glucose levels were measured by using a glucometer and test strips. Results: Gross examination showed faster wound closure in the laser exposed groups with minimal scar tissue formation in comparison with non-laser treated group. The clinical findings were confirmed by the histopathological study using Haematoxylin and Eosin and Masson’s Trichrome stain that revealed moderate inflammatory reaction in the laser group versus severe suppurative inflammatory reaction with keloid formation in the control non-treated group. Laser group also showed earlier granulation tissue formation and re-epithelization than non-treated control group. Conclusion: Low level laser therapy using diode laser 808 nm can be applied as an efficient method to accelerate wound healing in diabetic patient. Low level laser therapy has anti- inflammatory and antiseptic effects in addition to minimal scar tissue formation. [Ahmed.H.Osman ,Mahmoud .M. Kamel, Mohamed.H.Wahdan, Mahmoud Al-gazaly. Assessment to the Effects of Low Power Diode Laser on Wound Healing in Diabetic Rats. Life Sci J 2013; 10 (2): 1313-1321]. (ISSN: 1097- 8135). http://www.lifesciencesite.com Keywords: Diode Laser, Diabetes mellitus, wound healing, Pathology. 1. Introduction Diabetes is a complex metabolic disorder affecting many body organs and systems with devastate the lives of affected individuals [1]. The global incidence of diabetes gets to reach 6.6% (285 million people) in the end of 2010, and the number of people with diabetes will have increased to 438 million or 7.8% of the world’s population by 2030 [2]. Impairment wound healing is a very common complication of diabetes and a serious problem in clinical practice [3]. As many as 15% of people with diabetes will develop foot ulceration and wounds, on the other side 3% will have a lower limb amputation [4]. Wound healing is a complex and dynamic process which considered as a natural restorative response to tissue injury. Healing is the interaction of complex cascades of cellular events that associate with resurfacing, reconstitution, and restoration of the tensile strength of injured skin. Wound healing is a complex process involving various processes, as coagulation, inflammation, matrix synthesis, angiogenesis, fibroplasia, epithelization, contraction and remodeling. Growth factors are polypeptides that control the growth and differentiation of cells which regulate the process of tissue repair [5]. Healing is a systematic process, explained in three classic phases: inflammation, proliferation, and maturation. A clot formed phagocytic cells debride injured tissue during the inflammatory phase. Epithelialization, fibroplasias, and angiogenesis occur during the proliferative phase. Meanwhile, mature granulation tissue forms and the wound begin to contract [6]. Finally, during the maturation phase, collagen forms tight links to other collagen and with protein molecules that increasing scar tissue strength. An incision made through a full thickness of skin leads to a disruption of the microvasculature and immediate hemorrhage [7]. The vasoconstriction period is followed by long persistent period of vasodilatation which is responsible for the redness, edema and heat observed after tissue injury. Vasodilatation is an important means by which the wound can be exposed to increased blood flow, associated with the necessary inflammatory cells and factors that fight infection and debride the wound of devitalized tissue. The cellular aspect of the inflammatory phase occurs within hours of injury. Neutrophils are the most common cell type within the first 48 hours after injury. Macrophages are essential cells to wound healing through phagocytosis of debris and bacteria. Several defined