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The electric properties of polymers are increasingly important in a wide range of applications such as sensors, energy storages, microelectronics, and filtration membranes among others. In this work, the effect of multi-energetic Au ion implantation on the graphene oxide (GO), polyimide (PI), polyethylene terephthalate (PET) and polylactide (PLLA) elemental, chemical, structural end electric properties is presented with potential application in 3D metal-dielectric structure synthetization. The three energies, 3.2, 1.6, 0.8 MeV of Au ions with fluence 3.75×1014 cm-2 were used in ascending or descending order to create two sample sets, which were subsequently analysed by RBS, ERDA, EDS and AFM. RBS analysis was used for Au-depth profile characterization in the implanted samples, the profiles agree reasonably with those simulated by SRIM code. Electrical properties were investigated by standard two-point technique with respect to the used parameters of the ion irradiation. The sheet resistance decreases after ion irradiation and it is evident that the ascending order of ion implantation energies has more significant effect on the conductivity enhancement compare to the descending one.

The study deals with the cult of St. Denis, bishop of Paris and the French “national” patron saint, in medieval Bohemia and Moravia. It attempts to provide answers to the questions about the meaning, character and spread of the veneration of St. Denis in Czech society.

Unique properties of bacterial nanocelullose (BNC), such as high purity, water retention, nanofibrillar structure and non-cytotoxicity, allow its application in regenerative medicine, particularly for active wound healing and for skin tissue engineering. However, its biological activity is not fully sufficient to be considered a good cell scaffold. This can be enhanced by physicochemical modifications, particularly plasma treatment. In this work, air-dried (AD) or lyophilized (L) BNC samples were modified in a direct current Ar+ plasma discharge (PM). BNC_AD samples showed higher surface roughness, tensile strength and Young's modulus but a lower swelling ratio than BNC_L samples. The swelling ratio of BNC_L samples further increased after PM. The samples were subjected to six-day in vitro cell culture tests with normal human dermal fibroblasts (NHDFs) or human umbilical vein endothelial cells (HUVECs), i.e. cell types important for skin defect healing. NHDFs adhered in higher numbers, by a larger cell spreading area and reached higher cell population densities on PM samples than on unmodified samples. However, in HUVECs, this effect of PM on cell growth was less pronounced or even opposite, especially on mechanically weaker and more swellable BNC_L. At the same time, both cell types preferred mechanically stronger BNC_AD for their adhesion and growth, which was more apparent in HUVECs. The expression of mRNA for markers of cell adhesion and phenotypic maturation in NHDFs (talin, vinculin, CD90) was generally similar on BNC_PM and on tissue culture polystyrene. In HUVECs, the expression of vinculin and PECAM-1 on all BNC samples was lower than on polystyrene, but the expression of KDR (VEGF receptor 2) was higher, especially on BNC_PM. These results indicate cell type-specific differences in the response to various BNC modifications, which must be properly balanced to accommodate various cell types needed for wound healing and skin tissue engineering.

Here, we present surface analysis and biocompatibility evaluation of novel composite material based on graphene oxide traded as Hastalex. First, the surface morphology and elemental analysis of the pristine material were examined by atomic force and scanning electron microscopies, and by energy-dispersive and X-ray photoelectron spectroscopies, respectively. The Hastalex surface was then modified by plasma (3 and 8 W with exposure times up to 240 s), the impact of which on the material surface wettability and morphology was further evaluated. In addition, the material aging was studied at room and elevated temperatures. Significant changes in surface roughness, morphology, and area were detected at the nanometer scale after plasma exposure. An increase in oxygen content due to the plasma exposure was observed both for 3 and 8 W. The plasma treatment had an outstanding effect on the cytocompatibility of Hastalex foil treated at both input powers of 3 and 8 W. The cell number of human MRC-5 fibroblasts on Hastalex foils exposed to plasma increased significantly compared to pristine Hastalex and even to tissue culture polystyrene. The plasma exposure also affected the fibroblasts’ cell growth and shape.

The design of functional micro or nanostructured surfaces is undergoing extensive research for their intriguing multifunctional properties and for large variety of potential applications in biomedical field (tissue engineering or cell adhesion), electronics, optics or microfluidics. Such nanosized topographies can be easily fabricated by various lithography techniques and can be also further reinforced by synergic effect by combining aforementioned structures along materials with already outstanding antibacterial properties. In this work we fabricated novel micro/nanostructured substrates using soft lithography replication method and subsequent thermal nanoimprint lithography method, creating nanostructured films based on poly (l-lactic acid) (PLLA) fortified by thin silver films deposited by PVD. Main nanoscale patterns were fabricated by replicating surface patterns of optical discs (CDs and DVDs), which proved to be easy, fast and inexpensive method for creating relatively large area patterned surfaces. Their antimicrobial activity was examined in vitro against the bacteria Escherichia coli and Staphylococcus epidermidis strains. The results demonstrated that nanopatterned films actually improved the conditions for bacterial growth compared to pristine PLLA films, the novelty is based on formation of Ag nanoparticles on the surface/and in bulk, while silver nanoparticle enhanced and nanopatterned films exhibited excellent antibacterial activity against both bacterial strains, with circa 80 % efficacy in 4 h and complete bactericidal effect in span of 24 h.

We focused on polydimethylsiloxane (PDMS) as a substrate for replication, micropatterning, and construction of biologically active surfaces. The novelty of this study is based on the combination of the argon plasma exposure of a micropatterned PDMS scaffold, where the plasma served as a strong tool for subsequent grafting of collagen coatings and their application as cell growth scaffolds, where the standard was significantly exceeded. As part of the scaffold design, templates with a patterned microstructure of different dimensions (50 × 50, 50 × 20, and 30 × 30 μm2) were created by photolithography followed by pattern replication on a PDMS polymer substrate. Subsequently, the prepared microstructured PDMS replicas were coated with a type I collagen layer. The sample preparation was followed by the characterization of material surface properties using various analytical techniques, including scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS). To evaluate the biocompatibility of the produced samples, we conducted studies on the interactions between selected polymer replicas and micro- and nanostructures and mammalian cells. Specifically, we utilized mouse myoblasts (C2C12), and our results demonstrate that we achieved excellent cell alignment in conjunction with the development of a cytocompatible surface. Consequently, the outcomes of this research contribute to an enhanced comprehension of surface properties and interactions between structured polymers and mammalian cells. The use of periodic microstructures has the potential to advance the creation of novel materials and scaffolds in tissue engineering. These materials exhibit exceptional biocompatibility and possess the capacity to promote cell adhesion and growth.

Many bio-applicable materials, medical devices, and prosthetics combine both polymer and metal components to benefit from their complementary properties. This goal is normally achieved by their mechanical bonding or casting only. Here, we report an alternative easy method for the chemical grafting of a polymer on the surfaces of a metal or metal alloys using alkoxy amine salt as a coupling agent. The surface morphology of the created composites was studied by various microscopy methods, and their surface area and porosity were determined by adsorption/desorption nitrogen isotherms. The surface chemical composition was also examined by various spectroscopy techniques and electrokinetic analysis. The distribution of elements on the surface was determined, and the successful bonding of the metal/alloys on one side with the polymer on the other by alkoxy amine was confirmed. The composites show significantly increased hydrophilicity, reliable chemical stability of the bonding, even interaction with solvent for thirty cycles, and up to 95% less bacterial adhesion for the modified samples in comparison with pristine samples, i.e., characteristics that are promising for their application in the biomedical field, such as for implants, prosthetics, etc. All this uses universal, two-step procedures with minimal use of energy and the possibility of production on a mass scale.

In the case of polymer medical devices, the surface design plays a crucial role in the contact with human tissue. The use of AgNPs as antibacterial agents is well known; however, there is still more to be investigated about their anchoring into the polymer surface. This study describes the changes in the surface morphology and behaviour in the biological environment of polyetheretherketone (PEEK) with immobilised AgNPs after different surface modifications. The initial composites were prepared by immobilising silver nanoparticles from a colloid solution in the upper surface layers of polyetheretherketone (PEEK). The prepared samples (Ag/PEEK) had a planar morphology and were further modified with a KrF laser, a GaN laser, and an Ar plasma. The samples were studied using the AFM method to visualise changes in surface morphology and obtain information on the height of the structures and other surface parameters. A comparative analysis of the nanoparticles and polymers was performed using FEG-SEM. The chemical composition of the surface of the samples and optical activity were studied using XPS and UV-Vis spectroscopy. Finally, drop plate antibacterial and cytotoxicity tests were performed to determine the role of Ag nanoparticles after modification and suitability of the surface, which are important for the use of the resulting composite in biomedical applications.

Refractive index of binary systems water-poly(ethylene glycol) of different molecular weights at several temperatures from 283.15 to 363.15 K was measured. Refractive index strongly depends on molecular weight, mole fraction and temperature. Experimental data were correlated by four parameters’ relationship for dependence of refractive index on mole fraction of poly(ethylene glycol) and by three parameters’ relationship for dependence on molecular weight of poly(ethylene glycol). Obtained data can serve as an input data for subsequent study of these binary systems and especially for study of colloidal systems of metal nanoparticles in dispersion surrounding consisting of water and poly(ethylene glycol). Especially these data on refractive index are important for determination of nanoparticle size and zeta potential by dynamic light scattering. Obtained data on refractive index have been employed for correct and accurate determination of nanoparticle size and zeta potential. The size of Au nanoparticles was determined by dynamic light scattering. For comparison of this determination also a transmission electron microscopy and UV–vis spectroscopy have been employed in very good agreement. The optical properties of Au nanoparticles’ colloidal solutions were analyzed with UV–vis spectroscopy and showed a significant absorption peak maximum at 530 nm. Keywords: Water-poly(ethylene glycol), Refractive index, Temperature dependence, Data correlation, Au nanoparticles, Dynamic light scattering

Here, we aimed at the preparation of an antibacterial surface on a flexible polydimethylsiloxane substrate. The polydimethylsiloxane surface was sputtered with silver, deposited with carbon, heat treated and exposed to excimer laser, and the combinations of these steps were studied. Our main aim was to find the combination of techniques applicable both against Gram-positive and Gram-negative bacteria. The surface morphology of the structures was determined by atomic force microscopy and scanning electron microscopy. Changes in surface chemistry were conducted by application of X-ray photoelectron spectroscopy and energy dispersive spectroscopy. The changes in surface wettability were characterized by surface free energy determination. The heat treatment was also applied to selected samples to study the influence of the process on layer stability and formation of PDMS-Ag or PDMS-C-Ag composite layer. Plasmon resonance effect was determined for as-sputtered and heat-treated Ag on polydimethylsiloxane. The heating of such structures may induce formation of a pattern with a surface plasmon resonance effect, which may also significantly affect the antibacterial activity. We have implemented sputtering of the carbon base layer in combination with excimer laser exposure of PDMS/C/Ag to modify its properties. We have confirmed that deposition of primary carbon layer on PDMS, followed by sputtering of silver combined with subsequent heat treatment and activation of such surface with excimer laser, led to the formation of a surface with strong antibacterial properties against two bacterial strains of S. epidermidis and E. coli.

The main aim of this study was to describe the treatment of carbon sheet with a high-energy excimer laser. The excimer modification changed the surface chemistry and morphology of carbon. The appearance of specific carbon forms and modifications have been detected due to exposure to laser beam fluencies up to 8 J cm−2. High fluence optics was used for dramatic changes in the carbon layer with the possibility of Q-carbon formation; a specific amorphous carbon phase was detected with Raman spectroscopy. The changes in morphology were determined with atomic force microscopy and confirmed with scanning electron microscopy, where the partial formation of the Q-carbon phase was detected. Energy dispersive spectroscopy (EDS) was applied for a detailed study of surface chemistry. The particular shift of functional groups induced on laser-treated areas was determined by X-ray photoelectron spectroscopy. For the first time, high-dose laser exposure successfully induced a specific amorphous carbon phase.

Here, we report on the nanopatterning of different aromatic polymer substrates achieved by KrF excimer laser treatment. The conditions for the construction of the laser-induced periodic surface structures, the so-called LIPSS pattern, were established by optimized laser fluence and a number of pulses. The polymer substrates were polyethylene naphthalate (PEN), polyethersulfone (PES), and polystyrene (PS), which were chosen since they are thermally, chemically, and mechanically resistant polymers with high absorption coefficients at the excimer laser wavelength. The surface morphology of the treated substrates was investigated by atomic force microscopy and scanning electron microscopy, and the roughness and effective surface area on the modified samples were determined. Elemental concentration was characterized by energy-dispersive (EDX) analysis, surface chemistry was determined with X-ray photoelectron spectroscopy (XPS). The samples with the formation of LIPSS induced by 10 mJ·cm−2 with 1000, 3000, and 6000 pulses were used for subsequent in vitro cytocompatibility tests using human cells from osteosarcoma (U-2 OS). The LIPSS pattern and its ability of significant cell guidance were confirmed for some of the studied samples. Cell morphology, adhesion, and proliferation were evaluated. The results strongly contribute to the development of novel applications using nanopatterned polymers, e.g., in tissue engineering, cell analysis or in combination with metallization for sensor construction.

As polymeric materials are already used in many industries, the range of their applications is constantly expanding. Therefore, their preparation procedures and the resulting properties require considerable attention. In this work, we designed the surface of polyethylene naphthalate (PEN) introducing copper nanowires. The surface of PEN was transformed into coherent ripple patterns by treatment with a KrF excimer laser. Then, Cu deposition onto nanostructured surfaces by a vacuum evaporation technique was accomplished, giving rise to nanowires. The morphology of the prepared structures was investigated by atomic force microscopy and scanning electron microscopy. Energy dispersive spectroscopy and X-ray photoelectron spectroscopy revealed the distribution of Cu in the nanowires and their gradual oxidation. The optical properties of the Cu nanowires were measured by UV-Vis spectroscopy. The sessile drop method revealed the hydrophobic character of the Cu/PEN surface, which is important for further studies of biological responses. Our study suggests that a combination of laser surface texturing and vacuum evaporation can be an effective and simple method for the preparation of a Cu/polymer nanocomposite with potential exploitation in bioapplications; however, it should be borne in mind that significant post-deposition oxidation of the Cu nanowire occurs, which may open up new strategies for further biological applications.

A polydimethylsiloxane (PDMS) composite with multi-walled carbon nanotubes was successfully prepared. Composite foils were treated with both plasma and excimer laser, and changes in their physicochemical properties were determined in detail. Mainly changes in surface chemistry, wettability, and morphology were determined. The plasma treatment of PDMS complemented with subsequent heating led to the formation of a unique wrinkle-like pattern. The impact of different laser treatment conditions on the composite surface was determined. The morphology was determined by AFM and LCM techniques, while chemical changes and chemical surface mapping were studied with the EDS/EDX method. Selected activated polymer composites were used for the evaluation of antibacterial activity using Gram-positive (Staphylococcus epidermidis) and Gram-negative (Escherichia coli) bacteria. The antibacterial effect was achieved against S. epidermidis on pristine PDMS treated with 500 mJ of laser energy and PDMS-C nanocomposite treated with a lower laser fluence of 250 mJ. Silver deposition of PDMS foil increases significantly its antibacterial properties against E. coli, which is further enhanced by the carbon predeposition or high-energy laser treatment.

In this study, we present a simple approach for developing a biocompatible polymer scaffold with a honeycomb-like micropattern. We aimed to combine a plasma treatment of fluorinated ethylene propylene (FEP) substrate with an improved phase separation technique. The plasma exposure served for modification of the polymer surface properties, such as roughness, surface chemistry, and wettability. The treated FEP substrate was applied for the growth of a honeycomb-like pattern from a solution of polymethyl methacrylate (PMMA). The properties of the pattern were strongly dependent on the conditions of plasma exposure of the FEP substrate. The physico-chemical properties of the prepared pattern, such as changes in wettability, aging, morphology, and surface chemistry, were determined. Further, we have examined the cellular response of human osteoblasts (U-2 OS) on the modified substrates. The micropattern prepared with a selected combination of surface activation and amount of PMMA for honeycomb construction showed a positive effect on U-2 OS cell adhesion and proliferation. Samples with higher PMMA content (3 and 4 g) formed more periodic hexagonal structures on the surface compared to its lower amount (1 and 2 g), which led to a significant increase in the pattern cytocompatibility compared to pristine or plasma-treated FEP.

In this study, we have aimed at the preparation and characterization of poly-l-lactic acid (PLLA) composites with antibacterial properties. Thin bilayers of titanium and gold of various thickness ratios were deposited on PLLA by a cathode sputtering method; selected samples were subsequently thermally treated. The surface morphology of the prepared composites was studied by atomic force, scanning electron, and laser confocal microscopy. The chemical properties of the composites were determined by X-ray photoelectron and energy-dispersive X-ray spectroscopy in combination with contact angle and zeta potential analyses. The antibacterial properties of selected samples were examined against a Gram-negative bacterial strain of E. coli. We have found that a certain combination of Au and Ti nanolayers in combination with heat treatment leads to the formation of a unique wrinkled pattern. Moreover, we have developed a simple technique by which a large-scale sample modification can be easily produced. The dimensions of wrinkles can be tailored by the sequence and thickness of the deposited metals. A selected combination of gold, titanium, and heat treatment led to the formation of a nanowrinkled pattern with excellent antibacterial properties.

In this study, we present the surface patterning of a biopolymer poly(l-lactide) (PLLA) for fibroblast growth enhancement. The patterning is based on a self-organized pore arrangement directly fabricated from a ternary system of a solvent-nonsolvent biopolymer. We successfully created a porous honeycomb-like pattern (HCP) on a thermally resistant polymer—fluorinated ethylene propylene (FEP). An important preparation step for HCP is activation of the substrate in Ar plasma discharge. The polymer activation leads to changes in the surface chemistry, which corresponds to an increase in the substrate surface wettability. The aim of this study was to evaluate the influence of the PLLA concentration in solution on the surface morphology, roughness, wettability, and chemistry, and subsequently, also on fibroblast proliferation. We confirmed that the amount of PLLA in solution significantly affects the material surface properties. The pore size of the prepared layers, the surface wettability, and the surface oxygen content increased with an increasing amount of biopolymer in the coating solution. The optimal amount was 1 g of PLLA, which resulted in the highest number of cells after 6 days from seeding; however, all three biopolymer concentrations exhibited significantly better results compared to pristine FEP. The cytocompatibility tests showed that the HCP promoted the attachment of cell filopodia to the underlying substrate and, thus, significantly improved the cell–material interactions. We prepared a honeycomb biodegradable support for enhanced cell growth, so the surface properties of perfluoroethylenepropylene were significantly enhanced.

Homogeneous polystyrene foils doped with different concentrations of acetylsalicylic acid were prepared by the solvent casting method. The surface morphology and surface chemistry of as-prepared foils were characterized in detail. Excimer laser (krypton fluoride, a wavelength of 248 nm) was used for surface nanopatterning of doped polystyrene foils. Certain combinations of laser fluence and number of laser pulses led to formation of laser-induced periodic surface structures (LIPSS) on the exposed surface. Formation of the pattern was affected by the presence of a dopant in the polystyrene structure. Significant differences in surface chemistry and morphology of laser-treated foils compared to both pristine and doped polystyrene were detected. The pattern width and height were both affected by selection of input excimer exposure conditions, and the amount of 6000 pulses was determined as optimal. The possibility of nanostructuring of a honeycomb-like pattern doped with acetylsalicylic acid was also demonstrated. Selected nanostructured surfaces were used for study the antibacterial properties for a model bacteria strain of S. aureus. The combination of altered surface chemistry and morphology of polystyrene was confirmed to have an excellent antibacterial properties.

Relationship between Age Cognitive Decline and Performance of Cognitive Motor Tasks in Seniors Relationship between the age-related cognitive decline and decline in cognitive processing speed, in a variety of cognitive motor tasks was examined. The sample consisted of 33 well-adjusted older adults (on average 68 years old), recruited from several physical activity programs. The participants performed five cognitive tests selected from the Vienna test system battery. Subsequently, the relationship of their age and the measures of cognitive function was analyzed. It was found that the age of respondents was related only to their performance in complex tasks which included a processing speed component. The participant’s performance in simple tasks and in measures unaffected by processing speed was unrelated to age. Results are consistent with the processing speed theory of adult age differences in cognition (Salthouse, 1996). Furthermore, the performance in complex cognitive tasks was influenced by the level of participation in leisure physical activities; this suggests that physically active lifestyle may limit the impact of age on cognitive function. Stárnutí a rychlost zpracování kognitivních funkcí V předkládáné studii se zabýváme některými aspekty věkem podmíněného úbytku kognitivních funkcí. Konkrétně zkoumáme předpoklady vycházející z teorie rychlosti zpracování (Salthouse, 1996) týkající se toho, že věkem podmíněný pokles kognitivních funkcí je dán především poklesem rychlosti kognitivních procesů, což se projevuje především u komplexních kognitivních úkolů. Vzorek v naší studii se skládal z 33 seniorů a seniorek (průměrný věk byl 68 let), které jsme oslovili prostřednictvím několika programů pro seniory. Respondenti byli testováni prostřednictvím pěti testů kognitivních funkcí, které jsme vybrali z testové baterie Vienna test systém. Následně jsme analyzovali vztah mezi výsledky testů a věkem respondentů. Zjistili jsme, že věk respondentů souvisel s jejich výkony v testech pouze v komplexních úkolech, které obsahovaly komponenty rychlosti zpracování. Výkon respondentů v jednoduchých úkolech a v úkolech nezávislých na rychlosti zpracování nevykazoval vztah s jejich věkem. Naše zjištění jsou konzistentní s hypotézami vycházejícími z teorie rychlosti zpracování. Dále jsme zjistili, že výkon při řešení komplexních kognitivních úloh byl ovlivněn účastí ve volnočasové pohybové aktivitě, což naznačuje, že aktivní životní styl limituje dopad stárnutí na kognitivní funkce.