Young Wook Park

Paradoxical effects of elastase inhibitor guamerin on the tissue repair of two different wound models: sealed cutaneous and exposed tongue wounds

Innate elastase inhibitors are known to be putatively involved in the regulation of tissue inflammation by inhibiting polymorphonuclear leukocyte (PMN) derived proteinases. The aim of this study was to evaluate affects of leukocyte elastase suppression and PMN infiltration on wound healing in mouse by administering the recombinant elastase inhibitor guamerin (rEIG) in two different wound models; 1) impaired pin-punctured dorsal mucosa of anterior tongue wound, 60 mice, treated with saline containing rEIG that were fed ad libitum and 2) stable linear excisional cutaneous wound, 40 mice, covered with fibrin sealant containing rEIG. The progress of healing was analyzed by histological methods. The tongue wounds treated with rEIG became edematous around the pin-punctured tongue wound, and influx of inflammatory cells and PMN into the underlying stromal tissue were seen rapidly after wounding and peaked between 2-4 days. Whereas the control mice showed almost no wheal formation in the pin-punctured wound, a far lesser levels of PMN infiltration, and almost complete wound closure in 4 days. In the other model, the liner excisional cutaneous wound treated with fibrin sealant containing rEIG showed early wound constriction, lesser degree of inflammatory cells influx, and complete reepithelialization in 4-5 days, whereas the wound of control mice with the fibrin sealant alone showed contrary delayed reepithelialization, greater degree of inflammatory cell infiltration, and consequencial formation of greater granulation tissue at wound site. Taken together, these data suggest paradoxical effects of rEIG on the wound healing where in the wound exposed to infiltrating milieu of microorganisms in the oral cavity, the rEIG aggravates the wound healing by interfering with other innate defensive factors and extended greater flux of PMNs to inflamed wound site, while in the wound enclosed by fibrin, the rEIG accelerated wound healing by inhibiting the inflammation-generated proteases and the acute inflammatory reaction.

Powdered Wound Dressing Materials Made from wild Silkworm Antheraea pernyi Silk Fibroin on Full-skin Thickness Burn Wounds on Rats

Purpose: This study evaluated powdered burn wound dressing materials from wild silkworm fibroin in an animal model. Methods: Fifteen rats were used in this experiment. Full-thickness 2×2 cm burn wounds were created on the back of rats under anesthesia. In the two experimental groups, the wounds were treated with two different dressing materials made from silkworm fibroin. In the Control Group, natural healing without any dressing material was set as control. The wound surface area was measured at five days, seven days and 14 days. Wound healing was evaluated by histologic analysis. Results: By gross observation, there were no infections or severe inflammations through 14 days post-injury. The differences among groups were statistically significant at seven days and 14 days, postoperatively (P <0.037 and 0.001, respectively). By post hoc test, the defect size was significantly smaller in experimental Group 1 compared with the Control Group and experimental Group 2 at seven days postoperatively (P =0.022 and 0.029, respectively). The difference between Group 1 and Group 2 was statistically significant at 14 days postoperatively (P <0.001). Group 1 and control also differed significantly (P =0.002). Group 1 showed a smaller residual scar than the Control Group and Group 2 at 14 days post-injury. Histologic analysis showed more re-epithelization in Groups 1 and 2 than in the Control Groups. Conclusion: Burn wound healing was accelerated with silk fibroin spun by wild silkworm Antheraea pernyi. There was no atypical inflammation with silk dressing materials. In conclusion, silk dressing materials can be used for treatment of burn wound.

Double-layered reconstruction of the nasal floor in complete cleft deformity of the primary palate using superfluous lip tissue

After cleft lip repair, many patients suffer from nasolabial fistulas, asymmetrical nasal floor, or an indistinct nostril sill, as well as intraoral wound dehiscence and subsequent scar contracture of surgical wounds leading to vestibular stenosis. For successful primary nasolabial repair of complete cleft deformity of the primary palate, cleft surgeons need special care in reconstructing the sound nasal floor. Especially when the cleft gap is wide or when any type of nasoalveolar molding therapy was not performed, three-dimensional reconstruction of the nasal floor is critical for a balanced nasal shape. In this study, the author describes an effective method for reconstructing a double-layered nasal floor using two mucosal flaps from both sides of the fissured upper lip. This is a report of six patients with unilateral or bilateral complete cleft of the primary palate with a detailed description of the surgical technique and a literature review.