Nanoclay gels promote re-epithelialization and improve the quality of skin wound healing in a diabetic mouse model

Abstract There is evidence that sorptive clays have been used since prehistory as materials to treat skin abrasions and wounds. Despite this, there is a paucity of studies that systematically address the efficacy of defined clays in improving skin wound healing. In this study, we tested the hypothesis that a well-defined synthetic smectite clay, Laponite, enhances healing in a delayed skin wound healing model. Full-thickness skin wounds were made in the back skin of db/db and wild-type male adult mice (8–10 weeks), and Laponite clay gels or controls of phosphate-buffered saline (PBS) or alginate were applied after 24 h and held in place with a semi-occlusive dressing. Although Laponite treatment did not accelerate macroscopic wound closure, it significantly improved healing quality, including re-epithelialisation, epithelial cell division, epithelial thickness and fibroblast invasion, compared with PBS- or alginate-treated db/db mice. Moreover, hair follicle anagen was stimulated in proximity to Laponite-treated wounds, but was absent in PBS- or alginate-treated wounds. Neutrophil infiltration at day 18 was also reduced. In contrast to alginate, in which VEGF improved wound healing, VEGF in Laponite showed negligible additional benefit. These data indicate a role for synthetic nanoclay gels in wound healing.