Use of Povidone Iodine plus Diode Laser for Treatment of Infected Wound in Mice

Abstract

Objective: The study was aimed to evaluate the 660 nm (6J/cm2) laser treatment alone, povidone iodine alone, and the combination of both on healing of induced infected open wounds in mice. Methods: Forty adult male mice were utilized. Two open full-thickness (0.5cm in diameter) skin incision on the back of the animal were made. Infection was creating in the cranial incision with Pseudomonas aeruginosa (inoculation of 0.2 mL bacterial suspension containing 2x108 CFU/mL of P. aeruginosa after 24 hrs. from wounding). The caudal incision not inoculated, and left without treatment as control in the same animal. Animals were randomly divided into four groups (n 10). G1; Control group; not treated with povidone iodine or diode laser. G2; treated with single dose 6J/cm2 diode laser / day for 7 successive days post infection (PI). G3; treated only with topical application of 10% povidone iodine for 5 min/day for 7 successive days PI. G4; treated with a topical application of povidone iodine plus diode laser for 7 successive days PI. Direct measurement of wound dimensions at 7th and 14th days PI was done and specimens of healed skin for histopathological examination was taken. Results: Cranial wounds in G1 exhibit more pus at the 7th day PI, and at 14th day the size of wound become more wider, large quantity of pus under scab was seen, and the healing did not occur, also the infection was seen involving the distal wound in some animals. The cranial wounds of G2 at 7th day PI display inexistent of infection, the size of wound decreased more than 50% and become small, dry, with no scab. Histologically complete normal skin layers dermis and epidermis was seen. At 14th day PI, the wound become barely visible. In this time also, histologically complete epithelialization of both cranial and caudal incisions was developed. Cranial wounds of G3 at the 7th day PI display vanish infection, while wound still covered with scab, and little reduction in size in compare with control in same animal, and control group at 7th day. On the 14th day PI, complete epithelialization, and more reduction in size were seen. Histologically, regenerated epidermal layers with severe inflammatory infiltration were seen at 7th day, and normal skin structure seen at 14th day. Cranial wounds of G4 at the 7th day PI show inexistent of infection, presence of scab with more reduction in size in compare with day 0, and little reduction in size in compare with wounds of control in same animal. On 14th day PI the treated wounds show more reduction in size, no scab cover the incisions and complete epithelialization of both incisions reach hard to distinguished from the normal skin. Histologically demonstrate formation of an epithelized epidermis bridging between the wound edges, and newly formed hair follicle were seen at 7th day, and completely normal skin layers and cells were seen at 14th day. Conclusions: The 660 nm, 6J/cm2 LLLT used in this experiment effectively inexistent of the wound bacterial infection caused by Pseudomonas aeruginosa in mice, and enhancement of open wound healing. The 10% povidone iodine eradicates the infection, with negligible delay in wound healing in compare with laser group. The povidone iodine and laser interact additively or synergistically in enhancement of wound healing, and against wound infection in this experiment.