Evaluating the Effect of 3% Papain Gel Application in Cutaneous Wound Healing in Mice.

While the US Food and Drug Administration has not approved the use of 3% papain gel in the United States, the authors feel this study adds to the literature regarding its use. INTRODUCTION: The aim of this study was to evaluate the effect of 3% papain gel on wounds in mice. MATERIALS AND METHODS: Thirty healthy C57BL mice (25-30 g) aged 10 weeks were randomly divided into 2 groups: mice treated with 3% papain gel and mice treated with placebo gel. Skin incisions were performed with a 6-mm metallic punch with a cutting blade edge. On days 3 and 7 after creating the lesion, the mice were euthanized and lesion samples were collected. The lesion samples were processed and sectioned into 3 fragments of skin to be stained with 3 types of dye: hematoxylin and eosin, Picrosirius red, and Weigert. In addition, immunohistochemical analysis (α-SM actin and Ki67) followed by real-time polymerase chain reaction (PCR) protocol was performed on the samples. RESULTS: On gross examination, the 3% papain-treated group took less time to heal the wounds compared with the control. On day 7, microscopic examination showed the 3% papain-treated group had lower numbers of inflammatory cells, increased neovascularization, and improved organization of collagen and elastic fibers. Using PCR analysis, the 3% papain-treated group showed a significant increase in transforming growth factor beta and interleukin-6 expression compared with the control (P < .05). CONCLUSION: Due to a reduced local inflammatory response, increased angiogenesis, and improved organization of collagen deposition, these findings demonstrate 3% papain gel can improve cutaneous wound healing in mice.

XeCl excimer laser ablation of rabbit tibia bone: morphology of the irradiated site and self-limiting effect.

OBJECTIVE: The purpose of this work is to investigate the morphological changes of the rabbit tibia bone submitted to osteotomy with XeCl excimer laser. BACKGROUND DATA: Laser ablation of tissue is a relevant clinical application of high-power lasers. Due to the variety of laser wavelengths and properties of biological targets, the subject has not yet been completely explored. METHODS: In this study, four tibias were irradiated with six different durations. The applied energy density was 6.7 J/cm(2) per pulse at a 4-Hz repetition rate. RESULTS: The 24 samples had similar and well-defined craters that were free of carbonization. The ablation rates per pulse, at 60-120 seconds, were 3.8 and 1.9 microm at the compact bone and the marrow tissue, respectively. The ablation process ceased after 120 sec, with a 1.6-mm crater depth. CONCLUSIONS: In the present study, the laser used showed a self-limiting characteristic, which is a phenomenon that can be of great value in preserving important structures close to the working area, giving a margin of safety to the surgeon, in case of over-irradiation. This self-limiting effect is attributed to liquid filling the cavity by the bleeding and irrigation process.