Optimising Wound Healing in Aesthetic Surgery: From the Laboratory to the Clinic

137 The goal of any surgical or aesthetic procedure is to leave no scarring. For this, it is essential that wound healing should be optimised so that the skin heals without scars and as quickly as possible. A lot of research has been done on wound healing, but how much of this translates into actual clinical results remains to be seen. Two reviews in this issue focus on these aspects of wound healing; the role of topical retinoids in assisting wound healing following resurfacing procedures [1] and various modalities that increase neocollagenesis and neoelastogenesis in the dermis. Topical retinoids have been traditionally used before skin resurfacing procedures to enhance wound healing and reduce complications. Studies have shown that Vitamin A can enhance various aspects of wound healing by stimulation of angiogenesis, collagen synthesis, fibroplasia and epithelialisation. The site of action is mainly in the papillary dermis where topical tretinoin, the most well‑studied molecule, has been shown to increase Type I collagen production by 80% and also at the epidermal level causing epidermal hyperplasia with compaction of the stratum corneum and thickening of the granular layer. The mechanism of action of retinoids and their analogues is through the nuclear receptors (RARs [retinoic acid receptors] or RXRs [retinoic X receptors]) on cells. This interaction activates genes that contain RARE (retinoic acid response elements) or RXRE (retinoic X response elements) in their promoters. [6] They can also regulate gene expression by inhibiting the activity of other transcription factors, such as AP‑1. It has been hypothesized that AP‑1 may play a substantial role in the inflammation and immune response. [6] There are very few well‑designed studies that conclusively report on the optimum duration and strength of tretinoin that can assist wound healing. Most of the studies are on animal skin and a few studies in the clinic have shown conflicting results. In a study by Orringer et al., [7] application of 0.05% tretinoin 3 weeks before CO 2 laser resurfacing on the forearm skin did not show quicker re‑epithelialisation as compared to a control cream. In addition, there was no significant difference in levels of matrix metalloproteinases or pro‑collagens. On the contrary, a study by Popp et al. showed accelerated wound healing in tretinoin pre‑treated sites applied at a strength of 0.05% for 8 weeks, followed by 0.1% for another 8 weeks. There was a significant histological change in full‑thickness forearm skin biopsies. In …