Wound healing potential of a dimeric InlB variant analyzed by in vitro experiments on re-epithelialization of human skin models

A constitutively dimeric truncated variant of internalin B (InlB(321)-CD), acting as stimulator of the receptor tyrosine kinase MET, was tested for dermal wound-healing potential. Due to a lack of the endogenous MET agonist HGF/SF in chronic wounds, HGF/SF substitution by an InlB(321)-CD-loaded hydrogel might be beneficial in chronic wound therapy. In this study, InlB(321)-CD in solution and incorporated in a hydrogel was tested for mitogenic effects on immortalized human dermal keratinocytes (HaCaT) with an MTT assay. Cell migration was investigated with a scratch assay on primary keratinocytes (PHK) and on HaCaT. For the latter, scratching needed to be mitomycin C-controlled. InlB(321)-CD effects on a model of human skin were analyzed histologically with respect to viability. InlB(321)-CD led to dose-dependent proliferative effects on HaCaT cells whereas the equimolar dose of monomeric InlB(321) did not. Upon hydrogel incorporation of InlB(321)-CD its mitogenic activity for HaCaT cells was maintained thus confirming the hydrogel as a promising drug delivery system. Motogenic effects were shown on both HaCaT and PHK cells. InlB(321)-CD neither possesses cytotoxic effects on the viability of a human skin model nor alters its organotypic cell morphology. (c) 2013 Elsevier B.V. All rights reserved.