title: The effect of amphiphilic siloxane oligomers on fibroblast and keratinocyte proliferation and apoptosis.
abstract: The formation of hypertrophic scars (HSF) is a frequent medical outcome of wound repair and often requires further therapy with treatments such as silicone gel sheets (SGS) or apoptosis-inducing agents, including bleomycin. Although widely used, knowledge regarding SGS and their mode of action is limited. Preliminary research has shown that small amounts of amphiphilic silicone present in SGS have the ability to move into skin during treatment. We demonstrate herein that a commercially available analogue of these amphiphilic siloxane species, the rake copolymer GP226, decreases collagen synthesis on exposure to cultures of fibroblasts derived from HSF. By size exclusion chromatography, GP226 was found to be a mixture of siloxane species, containing five fractions of different molecular weight. By studies of collagen production, cell viability and proliferation, it was revealed that a low molecular weight fraction (fraction IV) was the most active, reducing the number of viable cells present after treatment and thereby reducing collagen production as a result. On exposure of fraction IV to human keratinocytes, viability and proliferation were also significantly affected. HSF undergoing apoptosis after application of fraction IV were also detected via real-time microscopy and by using the TUNEL assay. Taken together, these data suggests that these amphiphilic siloxanes could be potential non-invasive substitutes to apoptotic-inducing chemical agents that are currently used as scar treatments.
authors: Tissue Repair and Regeneration Program, Institute of Health and Biomedical Innovation, Queensland University of Technology, Kelvin Grove, Queensland, Australia. emily.lynam@qut.edu.au
authors: Emily C
authors: EC
authors: Lynam
authors: Yan
authors: Y
authors: Xie
authors: Bree
authors: B
authors: Loli
authors: Tim R
authors: TR
authors: Dargaville
authors: David I
authors: DI
authors: Leavesley
authors: Graeme A
authors: GA
authors: George
authors: Zee
authors: Z
authors: Upton
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D001672:Biocompatible Materials / Q000737:chemistry / Q000494:pharmacology; D049109:Cell Proliferation / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D017439:Cicatrix, Hypertrophic / Q000473:pathology; D018920:Coculture Techniques; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D006801:Humans; D015603:Keratinocytes / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D008422:Materials Testing; D012833:Siloxanes / Q000494:pharmacology*; D013501:Surface-Active Agents / Q000494:pharmacology*
chemical_list: D001672:Biocompatible Materials; D012833:Siloxanes; D013501:Surface-Active Agents