V. Švorčík

Adhesion and proliferation of cultured human aortic smooth muscle cells on polystyrene implanted with N+, F+ and Ar+ ions: correlation with polymer surface polarity and carbonization.

Physicochemical surface properties and biocompatibility were studied in polystyrene (PS) implanted with 150 keV N+, F+ and Ar+ at doses ranging from 1 x 10(12) to 1 x 10(15) cm-2. Adhesion and proliferation of cultured human aortic smooth muscle cells (SMCs) on ion implanted PS were thoroughly examined for dependence on implanted dose and ion species and in close relation to polymer surface oxidation, surface polarity, concentration of conjugated double bonds and sheet resistivity. The surface polarity of PS was a smooth, increasing function of the implanted dose. However, the dependence of SMC population density on the implanted dose was found to be more complicated. After 18 h cultivation time (i.e. when only cell attachment and spreading took place), the number of adhered SMCs and their degree of spreading first increased with increasing ion dose, and after reaching a maximum at the dose of 5 x 10(12) cm-2, they decreased to original values. For doses above 5 x 10(14) cm-2, an increase in SMC population density and spreading was again observed. The first maximum in cell adhesion can be explained by slight increases in the surface polarity and wettability, optimal for cell adhesion, and the second maximum by progressive carbonization of the PS surface. After 96 h cultivation time (i.e. when the cells proliferated intensively), the dramatic dependence of the SMC population density on implanted dose is mostly smeared out. This observed dependence of SMC attachment, spreading and subsequent proliferation on the implanted dose was similar in all three ion species, but highest cell densities were achieved on PS implanted with F+ ions.

Colonization of ion-modified polyethylene with vascular smooth muscle cells in vitro

Polyethylene (PE) foils were implanted with 40 and 150 keV Ar+ ions to the fluences from 1 x 10(13) to 1 x 10(15) cm(-2). Production of conjugated double bonds, characterizing degradation of the PE surface layer, was studied using UV-VIS spectroscopy. Wettability of the PE surface, determined by conventional goniometric techniques, was shown to be an increasing function of both ion energy and fluence. It was also increased after exposure of PE to serum-supplemented cell culture media. Cell culture experiments showed that the ion irradiation significantly increased the adherence of vascular smooth muscle cells (VSMC) and their subsequent growth on the PE surface. On day 1 after seeding, the number of initially adhered VSMC exhibited two maxima. On day 3 after seeding. these maxima disappeared, which was partially due to a significantly shorter doubling time of VSMC. On the other ion-modified samples. the doubling time did not differ significantly from that on the unmodified PE. Enzyme-linked immunosorbent assay revealed increased concentration of talin, a protein of focal adhesion plaques, and alpha-actin, a marker of VSMC differentiation, in cells on ion-implanted surfaces. It can be concluded that the ion irradiation supports the adhesion and differentiation of VSMC without excessive proliferation of these cells.

Poly- l - lactic acid modified by etching and grafting with gold nanoparticles

This work is focused on characterization of plasma treated and consequently etched and grafted biocompatible polymer poly(l-lactide acid) (PLLA). The interaction of biodegradable polymers with cold plasma is of a great importance in a tissue engineering and surface science. Cold plasma exposure, grafting with gold nanoparticles and etching processes were successfully applied to biopolymer substrate. A method for biopolymer nanostructuring as combination of cold plasma treatment and Au nanoparticle grafting for biocompatibility improvement is introduced. Surface roughness, morphology and surface chemistry was determined. The plasma modification leads to significant increase in surface roughness of PLLA and appearance of sharp spikes and ridges on the PLLA surface. Modification by grafting and etching leads to significant changes in PLLA surface morphology and chemistry. The surface ablation of PLLA has been proved to be significant. In etching of plasma-modified PLLA, methanol proves to be stronger etching agent than water. The grafting of PLLA with gold nanoparticles improved mouse embryonic fibroblasts (NIH 3T3) adhesion and proliferation significantly.

Electrokinetic Potential and Other Surface Properties of Polymer Foils and Their Modifications

© 2013 Kolska et al., licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Electrokinetic Potential and Other Surface Properties of Polymer Foils and Their Modifications

Growth of muscle cells on plasma-treated and gold nanoparticles-grafted polytetrafluoroethylene

Polytetrafluoroethylene (PTFE) was modified by Ar plasma with different exposure times. The plasma-activated surface was immersed in biphenyldithiol and subsequently in colloidal solution of Au nanoparticles. The changes in the surface wettability contact angle were examined by goniometry. Atomic force microscopy was used to determine the surface roughness and morphology. Changes in the chemical structure of the modified PTFE were studied using X-ray photoelectron spectroscopy (XPS) and electrokinetic analysis. The interaction of plasma-treated and grafted samples with vascular smooth muscle cell derived from the rat aorta was also studied. Specifically, the number and morphology of the adhered and proliferated cells on the PTFE were studied under in vitro conditions. The plasma treatment and the subsequent biphenyldithiol and Au nanoparticles grafting led to changes in the polymer surface chemistry, morphology, roughness and wettability. The polymer grafting with biphenyl-4,4′-dithiol (BFD) and subsequently with Au nanoparticles led to a decrease in the surface polarity. XPS measurements proved the presence of S and Au on the PTFE surface. Grafting with BFD and Au nanoparticles led to the decrease in surface roughness. In comparison with the pristine polymer, the plasma treatment and Au nanoparticles grafting increased the adhesion and proliferation of vascular smooth muscle cell.

Periodic nanostructure induced on PEN surface by KrF laser irradiation

There are several kinds of periodic surface structures, ranging from dots to ripples. The most common pattern is a ripple-like structure, where the direction of the ripples is parallel with the main polarisation of the laser beam. The distance between individual ripples (their period) depends on several factors, namely: the chemical structure of the polymer, wavelength of the laser irradiation and the angle of laser beam incidence. Oriented polyethylene naphthalate (PEN) foils with a thickness of 50 μm were used. The samples were irradiated with a KrF laser under laser beam incidence 0-45° to the laser beam. Selected polymer samples were also exposed by irradiation through a contact mask. Surface roughness and the dimensions of the ripple-like structures were measured by atomic force microscopy in tapping mode. The concentration of the elements on the surface was obtained from Angle Resolved X-ray Photoelectron Spectroscopy (ARXPS) spectra measured by X-ray Photoelectron Spectroscopy (XPS) spectrometer. The surface morphology and dimensions of prepared structures were evaluated and compared with those prepared on pristine samples without mask. The transition between the irradiated surface under the slits and the shielded surface in between the slits was evaluated. The optimal input parameters for nanopattern with high periodicity were determined. The shape and the surface roughness of the ripple pattern depend strongly on the angle of incidence of the laser beam. The surface roughness and ripple width increase with the angle of laser beam incidence. Irradiation with laser leads to changes in chemical composition of the PEN surface layer. Even at initial phase of pattern formation a significant increase of carbonyl and carboxyl groups was detected.

Wettability and Other Surface Properties of Modified Polymers

Surface wettability is one of the crucial characteristics for determining of a material’s use in specific application. Determination of wettability is based on the measurement of the material surface contact angle. Contact angle is the main parameter that characterizes the drop shape on the solid surface and is also one of the directly measurable properties of the phase interface. In this chapter, the wettability and its related properties of pristine and modified polymer foils will be described. The wettability depends on surface roughness and chemical composition. Changes of these parameters can adjust the values of contact angle and, therefore, wettability. In the case of pristine polymer materials, their wettability is unsuitable for a wide range of applications (such as tissue engineering, printing, and coating). Polymer surfaces can easily be modified by, e.g., plasma discharge, whereas the bulk properties remain unchanged. This modification leads to oxidation of the treated layer and creation of new chemical groups that mainly contain oxygen. Immediately after plasma treat‐ ment, the values of the contact angles of the modified polymer significantly decrease. In the case of a specific polymer, the strongly hydrophilic surface is created and leads to total spreading of the water drop. Wettability is strongly dependent on time from modification. Wettability plays a key role, e.g., in the development of biomaterials in tissue engineering and regenerative medicine. Biocompatibility tests of the cell adhesion, proliferation and viability are performed in an aqueous medium, and it is necessary to control the surface wettability. Various cell types have different requirements on surface properties, but while maintaining suitable parameters, the optimal value of

The Properties and Application of Carbon Nanostructures

Nanocomposite carbon-based substrates are a large group of materials promising for medicine and various biotechnologies, particularly for coating biomaterials designed for hard tissue implantation, constructing biosensors and biostimulators or micropatterned surfaces for creation of cell microarrays for advanced genomics and proteomics. These substrates comprise nanocomposite hydrocarbon plasma polymer films, amorphous carbon, pyrolytic graphite, nanocrystalline diamond films, fullerene layers and carbon nanotube and nanoparticles-based substrates. Polymer/carbon composites have attracted increasing interest owing to their unique properties and numerous potential applications in the automotive, aerospace, construction and electronic industries.

Noble Metal Nanoparticles Prepared by Metal Sputtering into Glycerol and their Grafting to Polymer Surface

This chapter summarizes the basic information about elementary characteristics and tech‐ nology of preparation of noble metal nanoparticles. The introduction gives some basic in‐ formation on the history of development in this area, especially in terms of dimensionality of metal nanostructures and their possible applications.The first subsec‐ tion is devoted to the preparation and characterization of Au, Ag, Pt, and Pd nanoparti‐ cles (NPs), which were synthesized by direct metal sputtering in liquid propane-1,2,3,triole (glycerol). This method provides an interesting alternative to time-consuming, wetbased chemical synthesis techniques. Moreover, the suggested technique allows targeted variation of metal nanoparticle size, which is demonstrated in detail in case of AuNPs by variation of capturing media temperature. Nanoparticle size and shape were studied by transmission electron microscopy and dynamic light scattering. Optical properties of nanoparticle solution were determined by measuring its UV–Vis spectra. Concentration of metal nanoparticles in prepared solutions was determined by atomic absorption spec‐ troscopy. Antibacterial properties were tested against two common pollutants (Escherichia coli, a Gram-negative bacteria, and Staphylococcus epidermidis, a Gram-positive bacteria). In the presence of Ag nanoparticles, the growth of E. coli and S. epidermidis was complete‐ ly inhibited after 24 h. Any growth inhibition of E. coli was observed neither in the pres‐ ence of “smaller” (4–6 nm, AuNP4–6) nor “bigger” (9–12 nm, AuNP8–12) AuNPs during the whole examination period. AuNP4–6, but not AuNP8–12, was able to inhibit the growth of. S epidermidis. We also observed significant difference in biological activities of Pt and PdNPs. More specifically, PdNPs exhibited considerable inhibitory potential against both E. coli and S. epidermidis, which was in contrast to ineffective PtNPs. Our results indicate that Ag, Pd, and partially AuNPs have high potential to combat both Gram-positive and Gram-negative bacterial strains.The second subsection describes the effort to anchor met‐ al nanoparticles onto polyethyleneterephthalate (PET) carrier. Two different procedures of grafting of polymeric carrier, activated by plasma treatment, with Au and AgNPs are described. In the first procedure, the PET foil was grafted with biphenyl-4,4’-dithiol (BPD) and subsequently with Au and AgNPs. In the second one, the PET foil was grafted with Au and AgNPs previously coated by the same BPD. X-ray photoelectron spectrosco‐

Nonconventional Method of Polymer Patterning

The unical properties of polymers, their cheap coast and possibility of easy chemical or physical modification, make these materials ideal building blocks for nanoor micropatterning. Techniques for polymers fabricating on nanoand micro-length scales span a wide range, from improved conventional lithographic methods to more recent materials and chemical advances that rely on self-organization of block copolymer. In addition to traditional methods, there are a number of techniques used exclusively in polymer materials processing. The most famous of them include molding, writing and printing, laser scanning, self-organization and surface instabilities utilization.