1,721,036 research outputs found

    The study of specific and non specific hepatoma cells behaviour by means of plasma treated substrates

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    Physical-chemical surface modifications represent a formidable tool to drive a suitable cell behavior on materials intended to be used in the biomedical field. Plasma processes are among the more powerful methods utilized to modify the surface of materials without altering their bulk intrinsic properties. In particular, by means of plasma treatment processes it is possible to graft chemical functional groups on polymer substrate. Functional groups grafted on the surface can improve per se cell adhesion and can also represent suitable anchor sites for biomolecule immobilization. The aim of this work was to determine the effect of plasma treatment and biomolecule immobilization on Polystyrene (PS) Petri dishes on the behavior of a human hepatocellular carcinoma cell line (HepG2). For this aim Petri dishes were grafted with N-containing groups in order to obtain grafted N-functionalities, to be used as anchor groups for the immobilization of galactosamine. In this way two different modified surfaces, NH3 grafted polystyrene (PS-NH3) and polystyrene owing galactosamine moieties (PS-NH3- GalNH2), have been obtained. Differences in cell morphology, urea and plasma Fibronectin (pFN) production were clearly observed on HepG2 seeded on PS-NH3 and PS-NH3- GalNH2. These results highlight the role of specific and non specific cell response in the in vitro study of materials intended to be used for biomedical purposes

    The active role of organic molecules in the formation of long-lived reactive oxygen and nitrogen species in plasma-treated water solutions

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    Plasma-treated water solutions (PTWS) allow the delivery of reactive oxygen and nitrogen species (RONS) to cells and tissues for different purposes. The mechanism of RONS formation has been clearly modelled in simple liquids like water, by assuming a plasma-driven process independent from the liquid. PTWS for biological experiments, however, are often produced from solutions of complex composition, where the formation mechanism of RONS is far from being understood. In this paper, we describe how water, phosphate-buffered saline solution and two cell culture media were plasma-treated in different conditions to demonstrate how the different composition of the liquids affects the formation of stable RONS (H2O2 and NO2−) in the resulting PTWS, especially when aromatic organic molecules are present

    Homogeneous and micro-patterned plasma-deposited PEO-like coatings for biomedical surfaces

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    Mixtures of diethyl glycol dimethyl ether vapors and argon were used to feed RF (13.56 MHz) glow discharges and coat polystyrene substrates with poly(ethylene oxide) (PEO)-like thin films. Different power input values have been used to obtain coatings with different cell-adhesive properties. Cell-culture experiments showed a tight correlation between the adhesion/morphology of cultured cell-lines and the chemical composition of the coatings; the ability of PEO-like coatings to discourage or promote cell adhesion could thus easily be related to the power delivered to the plasma. Combined deposition processes of different PEO-like coatings have been performed, with the method of physical masking, to produce surfaces micro-patterned with cell-adhesive tracks alternating with cell-repulsive domains. The micro-arrangement of different cell-adhesive domains enabled the patterning of cell cultures and induced the alignment of cells along predefined directions

    Functionalization of biomedical polymers by means of plasma processes: plasma treated polymers with limited hydrophobic recovery and PECVD of –COOH functional coatings

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    This short contribution is aimed to describe two plasma processes utilized at the group of the authors for biomedical applications, namely: the grafting process of polar groups intended to obtain stable hydrophilic surfaces on hydrophobic polymers, and the deposition of thin organic coatings highly functionalized with carboxylic groups. Both processes can develop cell-adhesive surfaces onto biomedical polymers. Combined with plasma deposition processes of non fouling coatings through a "physical mask", such methods can provide substrates patterned with diverse micrometric domains that can drive adhesion, spreading and growth of cells along predefined directions, an useful approach utilized in tissue engineering

    Plasma deposited acrylic acid coatings: surface characterization and the attachment of 3T3 murine fibroblasts cell lines

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    Two plasma deposited acrylic acid (pdAA) surfaces with very different surface density of COOH groups, wettability and stability in water were compared about their suitability to support adhesion and growth of 3T3 murine fibroblast cell lines. Polyethylenterephtalate (PET) and tissue culture polystyrene (TCPS) were used as control. PdAA surfaces with a low surface density of COOH groups (4 +/- 1%, from the C Is XPS spectra) resulted more cell adhesive than coatings with higher COOH density

    A nanoscale fluorocarbon coating on PET surfaces improves the adhesion and growth of cultured coronary endothelial cells

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    Plasma deposition was applied to deposit smooth and nanostructured fluorocarbon coatings on polyethylene terephthalate substrates, with the aim to obtain surfaces with identical chemical composition but different roughness to improve the endothelialization process on PET surfaces. We found that increased roughness was associated with enhanced endothelial cell response, as shown by the ability of cells to grow and adhere to nanostructures. We also observed specific interaction of filopodia protruding from the cell membrane with individual nanostructures, leading to increased cell attachment, spreading and cell viability. Among the modified surfaces, one termed PET-tfl90 emerged as the one capable of best sustaining the formation of a confluent monolayer of endothelial cells. In conclusion, PET modified by nanostructured fluorocarbon film represents an improved graft material, over conventional PET, for endothelial cell adhesion and growth

    Surface characterization of plasma deposited nano-structred fluorocarbon coatings for promoting in-vitro cell growth

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    Nano-structured "teflon-like" coatings characterized by highly-fluorinated, random, ribbon-shaped, micrometers-long structures were deposited on polyethylenetherephtalate (PET) substrates by plasma enhanced-chemical vapour deposition (PE-CVD) using modulated radiofrequency (RF, 13.56 MHz) glow discharges fed with C2F4 in modulated discharge (MD) and continuous wave (CW) regimes. Surfaces obtained in this way featured identical chemical composition and different roughness in the nanometric scale. Water contact angle (WCA) measurements, scanning electron microscopy (SEM) and atomic force microscopy (AFM) were utilized to characterize the surfaces. A positive relationship was shown to exist between the WCA value and the mean nano-structure height and the area root-mean-square (RMS) roughness of coatings. The possibility of obtaining coatings of varying nano-structure height, i.e., roughness, in a nanometric scale represents a promising result for further use of these surfaces as substrates for experiments on cell adhesion, proliferation and growth

    Novel plasma processes for biomaterials: micro-scale patterning of biomedical polymers

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    Plasma processes of interest for tissue engineering, biosensors and related applications have been utilized for micro-scale patterning polymers with 'physical masks'. The surface of polystyrene substrates has been patterned with different chemical micro-domains. each one able to induce different adhesion, spreading and growth behavior of cells. Cell adhesive tracks spaced with wider non-fouling PEO-like zones have been developed at the surface of the substrates, and utilized in cell growth experiments

    Stable plasma-plasma-deposited acrylic acid surfaces for cell culture applications

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    Continuous and modulated glow discharges were used to deposit thin films from acrylic acid vapors. Different deposition regimes were investigated, and their effect on chemical composition, morphology and homogeneity of the coatings, as well as on their stability in water and resistance to sterilization. Stable films were utilized in cell adhesion experiments with human fibroblasts
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