Comparison of the effectiveness between single and repeated administration of topical Tretinoin 0.05% on full-thickness acute wound healing

Abstract

Background: A wound is a discontinuity of any bodily tissue due to various causes. Every wound of any severity could result in problems related to its healing process, such as scar tissue formation. According to the duration of its healing process, wound is divided into 2 categories: acute wound that takes approximately 3-4 weeks to heal and chronic wound that needs 4-6 weeks and resulted from inappropriate healing of the acute wound. Tretinoin’s use in wound healing has been controversial for more than 40 years. Topical Tretinoin has keratolytic effect that stimulates fibroplasia and epithelization on full-thickness wounds. On the other hand, single administration along with long-contact topical Tretinoin has an irritative effect that could delay healing due to continuous inflammation. This study aims to explore the effectiveness of single administration compared to repeated administration of topical Tretinoin in full-thickness acute wound healing on rats at Faculty of Veterinary Medicine, Airlangga University, Surabaya. Methods: This experimental study involved 27 male rats which were randomly divided into 3 groups: control (A), single-administration (B), and repeated-administration (C). Full-thickness wound size 20 mm in diameter was made on the skin of each rat. On group A, wounds were covered with Tulle and transparent dressing. On group B, wounds were treated with lidocaine 2% and tretinoin solution 0,05% in single administration, while the same treatment was given repeatedly on group C for 4 days straight. Evaluation was done microscopically on day 5 according to epithelization phase on wound healing with hematoxylin and eosin (H&E) staining. Results: The result from the calculation showed that group C obtained a significantly higher average number of fibroblast cells count compared to the treatment group A and B. The average number of fibroblast cells in treatment group B was three times higher than the number of fibroblast cells in treatment group A, while the average number of fibroblast cells in treatment group C was three times the number of fibroblast cells in treatment group B. From the statistic, it was proven that the regular application of 0.05% topical tretinoin solution in a full-thickness wound (Group C) has shown a significant increase in the number of fibroblasts during the proliferative phase. Conclusion: A frequent administration of 0.05% topical tretinoin solution resulted in a higher number of fibroplasia improvements compared to once administered in full thickness acute wound healing, however it did not result in epithelialization on day 5.