Human skin cell cultures onto PLA50 (PDLLA) bioresorbable polymers: influence of chemical and morphological surface modifications.
ABSTRACT Poly(alpha-hydroxy acid)s derived from lactic and glycolic acid are bioresorbable polymers which can cover a large range of thermal, physical, mechanical, and biological properties. Human keratinocytes have been shown as able to grow on a poly(DL-lactic acid) film. However the keratinocyte growth was delayed with respect to culture on standard tissue culture polystyrene, even though the same plateau level was observed after 2 weeks. In order to improve the performance of poly(DL-lactic acid) films as skin culture support, their surface was modified by creating tiny cavities using a method based on the leaching out of poly(ethylene oxide) from poly(lactic acid)-poly(ethylene oxide) heterogeneous blends. The surface of the films was also chemically modified by alkaline attack with sodium hydroxide and by type-I collagen coating. Murine fibroblast cell line and primary cultures of human fibroblasts and of two types of keratinocytes were allowed to adhere and to grow comparatively on the different films. The presence of cavities affected neither the adhesion of dermal fibroblasts nor that of keratinocytes. Only keratinocyte proliferation was significantly reduced by the presence of cavities. Collagen coating improved skin cell adhesion and proliferation as well, except in the case of murine fibroblasts. In the case of the NaOH treatments, similar trends were observed but their extent depended on the treatment time. In the case of chemical modifications, fluorescence microscopy bore out adhesion and proliferation tendencies deduced from MTT tests.
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ABSTRACT: Poly(lactic acid)/titanium dioxide (TiO2) composite films were prepared by direct melt processing using three different procedures (i.e., compression molding, twin-screw melt extrusion, and melt extrusion and thermoforming). The effect of TiO2 loading and processing procedures on the phase morphology and on the thermal, mechanical, and barrier properties of the obtained nanocomposites were analyzed respectively by field-emission scanning electron microscopy-energy dispersive spectrometry, differential scanning calorimetry, universal testing machine, and water vapor and oxygen permeability measurements. The incorporation of TiO2 nanoparticles into the poly(lactic acid) matrix increased the crystallinity and improved the barrier properties of the composites. The maximum tensile strength was achieved at the 2% content of TiO2 for the films produced by compression molding and twin-screw melt extrusion, whereas the tensile strength for films produced by melt extrusion and thermoforming decreases markedly with an increasing TiO2 content. The photocatalytic activities of the obtained nanocomposites were investigated by analyzing the degradation of methyl orange. Results confirmed that the processing procedures and the distribution of TiO2 in the polymer matrix are the key parameters, which rule the photocatalytic behavior of composite films. POLYM. COMPOS., 2011. © 2011 Society of Plastics EngineersPolymer Composites 04/2011; 32(4). DOI:10.1002/pc.21068 · 1.48 Impact Factor
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ABSTRACT: Over the last years, increasing attention has been paid to skin engineering due to its predominant function in body integrity. Thus, many laboratories are attempting to develop a dermal–epidermal complex. The aim of this study was to evaluate the potential of poly(α-hydroxyacid)s in the development of biocompatible and bioresorbable dermal scaffold combining human fibroblasts and keratinocytes, in order to obviate the drawbacks of using natural polymers such as collagen, hyaluronic acid and fibrin. We first confirmed the interest of poly(d,l-lactic acid) (PLA50) during the reconstitution of epidermis and next, we investigated the potential of poly(d,l-lactic acid)-poly(ethylene glycol)-poly(d,l-lactic acid) (PLA50-PEG-PLA50) for either skin cytocompatibility or scaffold processing. Data showed that PLA50-PEG-PLA50 is compatible with the culture of human skin cells (fibroblasts and keratinocytes) and the development of a porous scaffold; two requirements compulsory for being considered as an adequate skin substitute. In fine, this material could represent the first generation of new skin dressings, i.e. a new concept taking advantage of both implantable devices and current dressings.Annales Pharmaceutiques Françaises 11/2008; 66(s 5–6). DOI:10.1016/j.pharma.2008.07.011
eXPRESS Polymer Letters 03/2014; 8(5):322-335. DOI:10.3144/expresspolymlett.2014.36 · 2.95 Impact Factor