Argon plasma-treated fluorinated ethylene propylene: Growth of primary dermal fibroblasts and mesenchymal stem cells

Surface modification is an important step in making a synthetic polymer cytocompatible. We have previously reported improved cytocompatibility of immortalized human keratinocytes (HaCaT) with the otherwise bioinert fluorinated ethylene propylene (FEP) upon treatment with argon plasma discharge. In this article, we show that FEP modified with Ar plasma with the power of 3 and 8 W for 40 and 240 s served as a suitable material for cultivation of primary human dermal fibroblasts (HDF), which showed significantly improved proliferation and spreading comparable to standard tissue culture polystyrene. We also evaluated focal adhesions formed by HDF cells on modified FEP, which were far more numerous compared to pristine FEP. Moreover, we attempted spontaneous osteogenic differentiation of adipose-derived mesenchymal stem cells modified with human telomerase reverse transcriptase on Ar plasma-modified FEP. While the spontaneous osteogenic differentiation was unsuccessful, the cells were able to adhere and differentiated on tested matrices upon the administration of osteodifferentiation medium. These combined findings suggest that the treatment of FEP with Ar plasma comprises and efficient method to enable the adhesion and proliferation of various cell types on an otherwise largely bioinert material.

Metformin reverses the effects of high glucose on human dermal fibroblasts of aged skin via downregulating RELA/p65 expression

Metformin has been successfully used as an anti-aging agent but exact molecular mechanisms of metformin in anti-aging remain unknown. Hyperglycemia during skin aging not only causes oxidative damage to cellular macromolecules, like dermal collagen, but also modulates the activation of transcription factor nuclear factor kappa B (NF-kB). We aimed to investigate in vitro effects of high glucose (HG) and metformin treatment on proliferation and apoptosis of human primary dermal fibroblasts (HDFs), and the expression of COL1A1, COL3A1, and RELA/p65 genes. Effects of normal glucose (5.5 mM) and HG concentration (50 mM HG) on HDFs, with two doses of metformin (50 μM and 500 μM), were investigated by immunostaining. Apoptotic levels were analyzed by flow cytometry. Expression of COL1A1, COL3A1, and RELA/p65 genes was measured by quantitative real-time PCR. The proliferation of HDFs was decreased significantly (P < 0.01) and expression of COL1A1 was downregulated by HG without metformin, whereas proliferation was elevated and expression was upregulated with 500 μM metformin + HG compared to 5.5 mM glucose (P < 0.05). The expression of COL3A1 and RELA/p65 were upregulated (P < 0.01 for COL3A1), and percentage of late apoptotic cells increased significantly by HG without metformin (P < 0.001) while it decreased in two concentrations of metformin dramatically compared with 5.5 mM glucose (P < 0.01 for expressions and < 0.001 for apoptosis). Metformin not only significantly downregulated RELA/p65 expression, but also inhibited the apoptosis of HDFs from aged human skin at toxic glucose concentrations which could be inversely mediated via COL1A1 and COL3A1 expression.