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This work aims to provide new insights into the link between the growth mechanisms of functionalized plasma polymer films (PPFs) and the substrate temperature (TS). By means of AFM‐based techniques, it has been demonstrated that the mechanical behavior of the coatings is dramatically affected by TS and the precursor employed (i.e., 1‐propanethiol or 1‐propylamine). While propylamine‐based PPFs behave as hard elastic materials regardless of TS, propanethiol‐based PPFs evolve from viscous liquids to elastic solids with increasing TS. This behavior can be understood considering the glass transition temperature of PPF. For both precursors, the latter is correlated to the cross‐linking density controlled through the energy density brought by positive ions to the growing film. [ABSTRACT FROM AUTHOR]

Poly(2-oxazoline) is a promising new class of polymeric materials due to their antibiofouling properties and good biocompatibility. Poly(2-oxazoline) coatings can be deposited on different substrates via plasma polymerization, which can be more advantageous than other coating methods. The aim of this study is to deposit poly(2-oxazoline) coatings using a surface dielectric barrier discharge burning in nitrogen at atmospheric pressure using 2-methyl-2-oxazoline and 2-ethyl-2-oxazoline vapours as monomers and compare the film properties. For the comparison, the antibacterial and cytocompatibility tests were peformed according to ISO norms. The antibacterial tests showed that all the deposited films were highly active against Staphylococcus aureus and Escherichia coli bacteria. The chemical composition of the films was studied using FTIR and XPS, and the film surface's properties were studied using AFM and surface energy measurement. The cytocompatibility tests showed good cytocompatibility of all the deposited films. However, the films deposited from 2-methyl-2-oxazoline exhibit better cytocompatibility. This difference can be explained by the different chemical compositions and surface morphologies of the films deposited from different monomers. [ABSTRACT FROM AUTHOR]

Laser-driven proton-boron (pB) fusion has been gaining significant interest for energetic alpha particles production because of its neutron-less nature. This approach requires the use of B- and H-rich materials as targets, and common practice is the use of BN and conventional polymers. In this work, we chose plasma-assisted vapour phase deposition to prepare films of oligoethylenes (plasma polymers) on Boron Nitride BN substrates as an advanced alternative. The r.f. power delivered to the plasma was varied between 0 and 50 W to produce coatings with different crosslink density and hydrogen content, while maintaining the constant thickness of 1 μm. The chemical composition, including the hydrogen concentration, was investigated using XPS and RBS/ERDA, whereas the surface topography was analyzed using SEM and AFM. We triggered the pB nuclear fusion reaction focusing laser pulses from two different systems (i.e., the TARANIS multi-TW laser at the Queen’s University Belfast (United Kingdom) and the PERLA B 10-GW laser system at the HiLASE center in Prague (Czech Republic)) directly onto these targets. We achieved a yield up to 108 and 104 alpha particles/sr using the TARANIS and PERLA B lasers, respectively. Radiative-hydrodynamic and particle-in-cell PIC simulations were performed to understand the laser-target interaction and retrieve the energy spectra of the protons. The nuclear collisional algorithm implemented in the WarpX PIC code was used to identify the region where pB fusion occurs. Taken together, the results suggest a complex relationship between the hydrogen content, target morphology, and structure of the plasma polymer, which play a crucial role in laser absorption, target expansion, proton acceleration and ultimately nuclear fusion reactions in the plasma.

Antibacterial coatings on biomedical instruments are of great interest because they can suppress bacterial colonization on these instruments. In this study, antibacterial polymeric thin coatings were deposited on teflon substrates using atmospheric pressure plasma polymerization from a propane–butane mixture. The plasma polymerization was performed by means of surface dielectric barrier discharge burning in nitrogen at atmospheric pressure. The chemical composition of plasma polymerized propane–butane films was studied by energy-dispersive X-ray spectroscopy (EDX) and FTIR. The film surface properties were studied by SEM and by surface energy measurement. The EDX analysis showed that the films consisted of carbon, nitrogen and oxygen from ambient air. The FTIR analysis confirmed, in particular, the presence of alkyl, nitrile, acetylene, imide and amine groups. The deposited films were hydrophilic with a water contact angle in the range of 13–23°. The thin film deposited samples were highly active against both S. aureus and E. coli strains in general. On the other hand, the films were cytocompatible, reaching more than 80% of the cell viability threshold compared to reference polystyrene tissue. [ABSTRACT FROM AUTHOR]

We report here on the development of tailored plasmonic AgNPs/C:H:N:O plasma polymer nanocomposites for the detection of the pathogenic bacterium Borrelia afzelii , with high selectivity and sensitivity. Silver (Ag) nanoparticles, generated by a gas aggregation source, are incorporated onto a C:H:N:O plasma polymer matrix, which is deposited by magnetron sputtering of a nylon 6.6. These anchored Ag nanoparticles propagate localized surface plasmon resonance (LSPR), optically responding to changes caused by immobilized pathogens near the nanoparticles. The tailored functionalization of AgNPs/C:H:N:O nanocomposite surface allows both high selectivity for the pathogen and high sensitivity with an LSPR red-shift Δλ > (4.20 ± 0.71) nm for 50 Borrelia per area 0.785 cm 2 . The results confirmed the ability of LSPR modulation for the rapid and early detection of (not only) tested pathogens., (© 2024 The Author(s). Journal of Biophotonics published by Wiley‐VCH GmbH.)

For the generation of tailor-made polymer coatings on nanofibrous nonwovens plasma enhanced chemical vapor (PECVD) is a promising process, even for complex geometries. The plasma coatings can greatly improve their suitability for biomedical applications by optimising biocompatibility to the local needs, especially for cardiovascular disease treatments. Therein, wound healing and endothelialisation are important steps which are connected by a complex interaction. The monomers allylamine and hexamethyldisiloxane, as well as different process conditions were studied for the coating of nanofibrous thermoplastic silicone polycarbonate polyurethane (TSPCU) nonwovens. Aim of this study was to investigate the feasibility of plasma polymer coating under preservation of the nanofibrous morphological structure. Beside characterization of the nonwoven, biological evaluation with endothelial and fibroblast cells was performed. The prepared nonwoven samples support the feasibility of plasma coating under preservation of the nanofibrous structure. Also, different effects of the surfaces in contact with fibroblasts and endothelial cells could be observed.

Hydrophobic coatings based on dodecyl acrylate (DOCA) and perfluorodecyl acrylate (PFDA) have been generated via "postdischarge" atmospheric pressure plasma deposition. These coatings exhibit a water contact angle (WCA) of around 125° but are accompanied by poor mechanical strength. To improve this property, two different types of chemical crosslinkers, that is, hexanediol methacrylate (HDMA) and hexanediol diacrylate (HDA), are incorporated into the precursor mixture. After plasma polymerization, both coatings with crosslinkers admixture show different wettability behavior. The addition of HDMA reduces the WCA while increasing the mechanical strength, while the addition of HDA retains the initial WCA magnitude while also increasing the mechanical strength. These changes are related to variations of the surface free energy (SFE) and topography of the plasma coatings. [ABSTRACT FROM AUTHOR]

There is a global epidemic of non-healing wounds. Chronic inflammation, overexpression of pro-inflammatory cytokines, oxidative stress and bacterial infection are implicated in delayed wound healing. Natural extracts are a rich source of bioactive molecules called plant secondary metabolites (PSMs) that include terpenes and phenols. These molecules may facilitate wound healing through their antioxidant, anti-inflammatory, and antibacterial activity. After briefly outlining the process of wound healing and how it is compromised in chronic wounds, this review focuses on investigating how PSMs-based polymers may improve wound healing. Best methods for incorporating PSMs into wound dressings are reviewed and critically compared. The exiting body of literature strongly suggests that PSMs-based polymers incorporated into wound dressings could have clinical value in aiding wound healing. Chronic wounds develop by the persistence of inflammation, oxidative stress and infection. Chronic wounds affect the worldwide population, by reducing quality of life of patients with significant cost to healthcare systems. To help chronic wounds to heal and overcome this burden, materials with anti-inflammatory, antioxidant and antibacterial properties are required. Plant secondary metabolites (PSMs) are volatile materials that have all these properties. PSMs-based polymers can be fabricated by polymerization techniques. The present review provides an overview of the state-of-the-art of the wound healing mechanisms of PSMs. Current developments in the field of PSMs-based polymers are reviewed and their potential use as wound dressings is also covered. [Display omitted] [ABSTRACT FROM AUTHOR]

Acrylic acid‐styrene copolymer films were deposited plasma‐chemically more gently using the pulsed plasma mode instead of the continuous mode, with linear and some slightly branched chains and marginal crosslinking. Then, the styrene unit of copolymers was wet‐chemically sulfonated by chlorosulfuric acid. On exposure to air, the formed 4‐chlorosulfonic acid groups hydrolyze to sulfonic acid groups (–SO3H). Fourier transform infrared spectroscopy, X‐ray photoelectron spectroscopy, and broadband dielectric spectroscopy were employed to characterize the composition, structure, functional groups, and electrochemical performance of the copolymers. A high concentration of sulfonic acid‐containing groups was obtained in the sulfonated polystyrene sample. The values of the DC conductivity σDC for the sulfonated sample of the acrylic acid and styrene copolymer are ca. five orders of magnitude higher than that of the not‐sulfonated copolymer materials. [ABSTRACT FROM AUTHOR]

Molecular dynamics simulations are carried out for studying the growth and properties of polymers from pure acetylene plasma. A mixture of H, C2H, and C2H2 is the initial composition used for running the molecular dynamics simulations. The resulting films are characterized by determining the bond order, [H]/[C] ratio, and simulated infrared spectrum. The latter is qualitatively compared with three different experiments: IR peak identification and positions are recovered. [ABSTRACT FROM AUTHOR]

Electrochemical immunosensors are an emerging technology for the fast, sensitive, and reliable diagnosis of diseases from bodily fluids. These sensors work by detecting a change in current upon analyte binding to an immuno‐functionalized electrode. Current methods of electrode functionalization are lengthy processes involving self‐assembled monolayer formation and wet chemistry biofunctionalization. Herein, thin films deposited from the plasma phase of oxazoline precursors are investigated and optimized as an alternative approach for electrode functionalization. The plasma‐enabled method has the advantage of being substrate independent and allows the spontaneous binding of biomolecules in physiological buffer. Surface sensitive analysis techniques are employed to characterize the thickness, reactivity, and stability of the thin films before investigating their electrochemical properties on indium tin oxide and gold electrodes including the feasibility to reduce charge transfer resistance with gold nanoparticles. Last, these films are employed to develop an immunosensor for the detection of free epithelial cell adhesion molecule with a limit of detection of 8.7 ng mL−1. [ABSTRACT FROM AUTHOR]

Abstract Background Biomaterial modifications—chemical and topographical—are of particular importance for the integration of materials in biosystems. Cells are known to sense these biomaterial characteristics, but it has remained unclear which physiological processes bio modifications trigger. Hence, the question arises of whether the dynamic of intracellular calcium ions is important for the characterization of the cell–material interaction. In our prior research we could demonstrate that a defined geometrical surface topography affects the cell physiology; this was finally detectable in a reduced intracellular calcium mobilization after the addition of adenosine triphosphate (ATP). Results This new contribution examines the cell physiology of human osteoblasts concerning the relative cell viability and the calcium ion dynamic on different chemical modifications of silicon–titanium (Ti) substrates. Chemical modifications comprising the coating of Ti surfaces with a plasma polymerized allylamine (PPAAm)-layer or with a thin layer of collagen type-I were compared with a bare Ti substrate as well as tissue culture plastic. For this purpose, the human osteoblasts (MG-63 and primary osteoblasts) were seeded onto the surfaces for 24 h. The relative cell viability was determined by colorimetric measurements of the cell metabolism and relativized to the density of cells quantified using crystal violet staining. The calcium ion dynamic of osteoblasts was evaluated by the calcium imaging analysis of fluo-3 stained vital cells using a confocal laser scanning microscope. The positively charged nano PPAAm-layer resulted in enhanced intracellular calcium ion mobilization after ATP-stimulus and cell viability. This study underlines the importance of the calcium signaling for the manifestation of the cell physiology. Conclusions Our current work provides new insights into the intracellular calcium dynamic caused by diverse chemical surface compositions. The calcium ion dynamic appears to be a sensitive parameter for the cell physiology and, thus, may represent a useful approach for evaluating a new biomaterial. In this regard, reliable in vitro-tests of cell behavior at the interface to a material are crucial steps in securing the success of a new biomaterial in medicine.

An atmospheric pressure plasma chemical vapor deposition process designed for the site‐selective deposition of organic functional materials with a sub‐millimetric lateral resolution is presented in this study. Injecting methyl methacrylate vapor in plasma post‐discharge allowed to synthesize plasma‐polymerized methyl methacrylate (ppMMA) coatings on metallic, dielectric, and polymer substrates at close to room temperature (40°C). A circular dot, as small as 400 µm in diameter, of ppMMA is deposited and characterized by Fourier‐transform infrared spectroscopy, X‐ray photoelectron spectroscopy, and high‐resolution mass spectrometry. Oligomeric species of poly‐MMA up to n = 18 have been detected, evidencing the particularly "soft" polymerization offered by the presented process. [ABSTRACT FROM AUTHOR]

Thin polymeric coatings are commonly used for altering surface properties and modulating the interfacial performance of materials. Possible contributions from the substrate to the interfacial forces and effects are, however, usually ignored and are not well understood, nor is it established how the coating thickness modulates and eventually eliminates contributions from substrates to the van der Waals (vdW) interfacial force. In this study we quantified, by colloid-probe atomic force microscope (AFM) and by theoretical calculations, the interfacial vdW contributions from substrates acting through ethanol plasma polymer (EtOHpp) coatings of a range of thicknesses on Au and Si bulk materials. In approach force curves against EtOHpp-coated Au substrates the magnitude of the vdW force decreased as the EtOHpp coating thickness increased to 18 nm and then plateaued with further increases in coating thickness, providing direct evidence for a contribution to the total interfacial vdW force from the Au substrate acting through thin coatings. The experimental observations accord with theoretical calculations of the thickness dependence of Hamaker coefficients derived from rigorous simulation using the Lifshitz theory. In addition, the measured forces agree well with theoretical predictions including correction for finite roughness. Thus, our experimental and theoretical results establish how the thickness of polymer thin film coatings modulates the total interfacial vdW force and how this can be used to tune the net vdW force so as to either contain a large substrate contribution or arise predominantly from the polymeric overlayer. Our findings enable rational design of coating thickness to tailor interfacial interactions and material performance. [ABSTRACT FROM AUTHOR]

In this communication, we report on an innovative solvent‐free method that allows for the design of nano‐/micropatterns with tuneable dimensions. Our approach is based on the spontaneous wrinkling phenomenon taking place in a bilayer system formed by a mechanically responsive bottom plasma polymer layer and a top aluminum thin film. The dimensions of the wrinkles can be adjusted in a wide range (i.e., from nanometer to micrometer range) by modulating the cross‐linking density as well as the thickness of the plasma polymer layer. Finally, it is demonstrated that these wrinkled surfaces could efficiently be used as flexible electrodes. The whole set of our data unambiguously reveals the attractiveness of our method for the fabrication of the micro‐/nanopattern with dimensions on demand. [ABSTRACT FROM AUTHOR]

Plasma polymer coatings fabricated from Melaleuca alternifolia essential oil and its derivatives have been previously shown to reduce the extent of microbial adhesion on titanium, polymers, and other implantable materials used in dentistry. Previous studies have shown these coatings to maintain their performance under standard operating conditions; however, when used in e.g., a dental implant, these coatings may inadvertently become subject to in situ cleaning treatments, such as those using an atmospheric pressure plasma jet, a promising tool for the effective in situ removal of biofilms from tissues and implant surfaces. Here, we investigated the effect of such an exposure on the antimicrobial performance of the Melaleuca alternifolia polymer coating. It was found that direct exposure of the polymer coating surface to the jet for periods less than 60 s was sufficient to induce changes in its surface chemistry and topography, affecting its ability to retard subsequent microbial attachment. The exact effect of the jet exposure depended on the chemistry of the polymer coating, the length of plasma treatment, cell type, and incubation conditions. The change in the antimicrobial activity for polymer coatings fabricated at powers of 20–30 W was not statistically significant due to their limited baseline bioactivity. Interestingly, the bioactivity of polymer coatings fabricated at 10 and 15 W against Staphylococcus aureus cells was temporarily improved after the treatment, which could be attributed to the generation of loosely attached bioactive fragments on the treated surface, resulting in an increase in the dose of the bioactive agents being eluted by the surface. Attachment and proliferation of Pseudomonas aeruginosa cells and mixed cultures were less affected by changes in the bioactivity profile of the surface. The sensitivity of the cells to the change imparted by the jet treatment was also found to be dependent on their origin culture, with mature biofilm-derived P. aeruginosa bacterial cells showing a greater ability to colonize the surface when compared to its planktonic broth-grown counterpart. The presence of plasma-generated reactive oxygen and nitrogen species in the culture media was also found to enhance the bioactivity of polymer coatings fabricated at power levels of 10 and 15 W, due to a synergistic effect arising from simultaneous exposure of cells to reactive oxygen and nitrogen species (RONS) and eluted bioactive fragments. These results suggest that it is important to consider the possible implications of inadvertent changes in the properties and performance of plasma polymer coatings as a result of exposure to in situ decontamination, to both prevent suboptimal performance and to exploit possible synergies that may arise for some polymer coating-surface treatment combinations.

This contribution reviews plasma polymer nanoparticles produced by gas aggregation cluster sources either via plasma polymerization of volatile monomers or via radio frequency (RF) magnetron sputtering of conventional polymers. The formation of hydrocarbon, fluorocarbon, silicon- and nitrogen-containing plasma polymer nanoparticles as well as core@shell nanoparticles based on plasma polymers is discussed with a focus on the development of novel nanostructured surfaces.

In this study we investigate the ability of RF magnetron sputtered nylon 6,6 films (C:H:N:O) to store and release two model antibiotics, ampicillin and ciprofloxacin, that differ significantly in their chemical structure. We demonstrate that the addition of nitrogen to the deposition process leads to a substantial enhancement in the abundance of nitrogen-containing functional groups in the resulting coatings as well as to the significant changes in their swelling and dissolution. These variations were found to result in different impregnation and release capabilities of the produced coatings: an almost 5 times higher amount of released antibiotics was observed for the samples prepared in nitrogen-rich atmosphere when compared to films deposited in pure argon. It was also found that the amount of released antibiotics strongly depends on the natural character of the antibiotics used. However, it is demonstrated that minimum inhibitory concentrations against S. epidermidis and E. coli can be exceeded for both antibiotics. • Ability of magnetron sputtered nylon films to store/release antibiotics was studied. • The highest storage capability was found for films sputtered in N 2 -rich atmosphere. • MIC of released ampicillin and ciprofloxacin against model bacteria was reached. • C:H:N:O films impregnated with antibiotics may be used as antibacterial coatings. [ABSTRACT FROM AUTHOR]

This study aims at deposition and characterization of antibacterial, hydrophobic and semitransparent metal/plasma polymer nanocomposite coating, containing Ag nanoparticles, onto cotton fabrics intended to be used in medical applications. The nano composite coatings were obtained via a simple, one step and ecofriendly plasma based co-deposition approach where silver was magnetron sputtered simultaneously with plasma polymerization of hexamethyldisiloxane (HMDSO) monomer. The nanocomposite thin films containing different concentration of silver were deposited either by varying silver sputter rate or thickness of the plasma polymer matrix to obtain a good balance between optical properties of the coated fabric and its long term antibacterial performance. The obtained coatings were investigated in detail with respect to their composition, morphology, optical properties, nanoparticle size distribution, silver ion release efficiency, antibacterial performance, water contact angle and washing stability of the coating. The thickness of the plasma matrix was found to be more important in controlling the release of silver ions as well as affecting the optical properties of the coating. The water contact angle on the coated fabric was up to 145°, close to super hydrophobicity. The coating showed effective antibacterial efficacy against Staphylococcus epidermidis (a Gram positive bacterium) which was present even when fabric was subjected to 10 repeated washing cycles indicating good washing stability of the coating. [ABSTRACT FROM AUTHOR]

A multilayer plasma polymer coating was deposited on small glass discs and afterwards treated with ultra violet radiation through a patterned mask to generate a micro-structured substrate with an alternating hydrophilic/hydrophobic surface. The substrate was then immersed in a mother liqueur of the porous, functional material Metal-Organic Framework Ulm-4 (MFU-4) to preferentially grow crystals on the hydrophilic areas of the film. X-ray diffraction and electron microscope analysis showed the formation of MFU-4 single crystals. • Chemically robust micro-structured, multilayer plasma polymer coating • Hydrophobic polytetrafluoroethylene-like coating deposited from trifluoromethane • Spatially directed crystal growth of a porous functional material [ABSTRACT FROM AUTHOR]

• Catechol functional PMMA layers are deposited by cold atmospheric pressure plasma. • A chemical cross-linker improves the deposition rate and layer stability in PBS. • Biosurfactant Ranaspumin-2 binding is revealed by QCM-D and SPR measurements. • The bioconjugated surfaces show excellent resistance towards HSA absorption. The deposition of polymeric thin layers bearing reactive functional groups is a promising solution to provide functionality on otherwise inert surfaces, for instance, for bioconjugation purposes. Atmospheric pressure plasma (AP plasma) deposition technology offers many advantages, such as fast deposition rates, low costs, low waste generation and suitability for coating various kind of material surfaces. In this work, the AP plasma-assisted copolymerization of methyl methacrylate (MMA) with a vinyl derivative of L-DOPA was studied in order to deposit coatings with reactive catechol/quinone groups suitable for protein covalent immobilization. The effect of adding a chemical cross-linker, between 0 and 2 mol%, to the monomer mixture is also studied in order to prepare robust plasma PMMA-based layers in liquid physiological media. The layer prepared with 0.2 mol% of cross-linker shows the best balance between stability in saline-buffered media and surface functionalization. Bioconjugation via the grafting of Ranaspumin-2 recombinant, a naturally occurring surfactant protein, is carried out in a single step after plasma deposition. Protein immobilization is corroborated by Quartz Crystal Microbalance with Dissipation (QCM-D) and Surface Plasmon Resonance (SPR) analyses and confirmed via Epicocconone staining, X-Ray Photoemission Spectroscopy (XPS) and Time of Flight Secondary Ion Mass Spectrometry (ToF-SIMS) measurements and surface wettability characterizations. The bio-functionalized layers presented an enhanced activity against the adhesion of Human Serum Albumin (HSA), indicating the grafting potential of the Ranaspumin-2 bio-surfactant to produce anti-biofouling functional coatings. [ABSTRACT FROM AUTHOR]

Chronic wounds fail to heal and are accompanied by an ongoing infection. They cause suffering, shorten lifespans, and their prevalence is increasing. Unfortunately, the medical treatment of chronic wounds has remained unchanged for decades. A novel approach to break the biological vicious cycle is the long-lived radical (2,2,6,6-Tetramethylpiperidin-1-yl)oxyl (TEMPO). TEMPO can be plasma polymerised (TEMPOpp) into thin coatings that have antimicrobial properties. However, due to its radical nature, quenching causes it to lose effectiveness over time. Our aim in this study was to extend the shelf-life of TEMPOpp coatings using various storage conditions: Namely, room temperature (RT), room temperature & vacuum sealed (RTV), freezer temperature & vacuum sealed (FTV). We have analysed the coatings’ quality via the surface analytical methods of X-Ray Photoelectron spectroscopy (XPS) and electron paramagnetic resonance (EPR); finding marked differences among the three storage conditions. Furthermore, we have compared the antimicrobial efficacy of the stored coatings against two major bacterial pathogens, Staphylococcus aureus and Staphylococcus epidermidis, commonly found in chronic wounds. We did so both qualitatively via live/dead staining, as well as quantitatively via (2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino) carbonyl]-2H-tetrazolium (XTT) viability assay for up to 15 weeks in 5 weeks increments. Taken all together, we demonstrate that samples stored under FTV conditions retain the highest antimicrobial activity after 15 weeks and that this finding correlates with the retained concentration of nitroxides.

Abstract This work aims at presenting an innovative method for tailoring the morphology of functionalized plasma polymer films (PPF). The approach is based on the formation of a plasma polymer bilayer system in which the two layers differ by their chemical composition and cross-linking degree. As a case study, propanethiol-based plasma polymer films have been investigated. As revealed by a much higher S/C ratio than in the propanethiol precursor (i.e. 0.83 vs 0.33), it has been demonstrated that the bottom layer contains a large fraction of trapped sulfur-based molecules (e.g. H 2 S). When further covered by a denser PPF formed at higher energetic conditions, a three-dimensional morphological reorganization takes place giving rise to the micro/nano structuration of the organic material. The shape, the dimensions as well as the density of the generated structures are found to depend on the thickness of both coatings involved in the bilayer structure, offering a great flexibility for surface engineering. Annealing experiments unambiguously confirm the major role played by the sulfur-based trapped molecules for inducing the reshaping process. The whole set of data clearly paves the way for the development of an innovative approach for finely tailoring the morphology of functionalized PPF at the micro/nano scale. Highlights • Synthesis of a bilayer system formed by two different propanethiol plasma polymers • Formation of micro/nano structured sulfur-based plasma polymers • Study of the reshaping mechanism [ABSTRACT FROM AUTHOR]

Introduction: The next generation of wound dressings will actively participate in the wound healing process, helping the body to heal itself. For deep and/or chronic wounds a dermal scaffold is often required prior to the application of a skin graft or other therapy that encourages re-epithelialisation and the restoration of the barrier function. The aim of this study was to determine if electrospinning and plasma polymerisation could be used to generate a scaffold that would support fibroblast growth and extracellular deposition. Methods: A totally synthetic electrospun dermal replacement was produced coated with an allylamine plasma polymer and its impact upon cellular processes assessed in vitro. Results: The scaffold encouraged increased adhesion and rapid migration of human dermal fibroblasts into the scaffold. Fibroblasts rapidly proliferated to populate the scaffold and deposited significantly more collagen I on scaffolds coated with the allylamine plasma polymer than the uncoated poly(lactic acid) scaffold or scaffolds coated with other plasma polymers (acrylic acid or 1,7' octadiene). Conclusions: Electrospinning and plasma polymerisation are both versatile and widely used techniques that are also suitable for large-scale manufacture of scaffolds. These properties increase the potential of the scaffold to include its use as a cell delivery device for the delivery of fibroblasts, including their associated extracellular matrix and mitogens to chronic wounds. [ABSTRACT FROM AUTHOR]

Sustainable marine antifouling strategies aim to minimize long term environmental impacts while effectively preventing surface colonization. In this study, we report upon a biodegradable antifouling coating for marine applications. In two stages, thin bilayers were produced using plasma-enhanced chemical vapor deposition of terpinen-4-ol, at applied powers of 100 W initially and then 10 or 25 W. The resulting coatings were characterized for solubility, surface energy, surface roughness and optical transmission. Both coatings exhibited similar solubility over the initial 14 days of observation, though structures deposited at 25 W were significantly more stable after 14 days. Coatings were smoother than the control surface upon which they were deposited and had higher hydrophobicity with transmission efficiencies >90% (400–1000 nm). Field assessments of the samples were carried out in Curralea Lake (Townsville, Australia) to assess their real world performance. Results indicate that the environmentally friendly coatings, terpinen-4-ol plasma polymer influenced antifouling. The proposed mechanism for this effect is the dissolution of the coating coupled with possible antimicrobial properties of the terpinen-4-ol. These results point to the potential usefulness of developing multilayer coatings for extended deployments. [ABSTRACT FROM AUTHOR]

Herein COOH/anhydride functionalized biodegradable nanofibers were prepared using atmospheric pressure plasma copolymerization of maleic anhydride (MA) and C 2 H 2 . The XPS and ATR-FTIR analyses revealed a high concentration of carboxyl and anhydride groups that were used for grafting of gentamycin (GM) onto the surface of PCL nanofibers. It was shown that GM can be immobilized either with or without dicyclohexyl carbodiimde (DCC). The immobilization without DCC led to ionic bonding (PCL-MA-GMi), whereas the immobilization using DCC activation resulted in covalent bonding (PCL-MA-GMc). The investigation of IAR2 epithelial cell adhesion and proliferation revealed that the GM-loaded nanofibers were biocompatible. The nanofibers without immobilized GM did not show any noticeable antibacterial activity against E. coli bacteria with different resistance to gentamicin. In contrast, the size of inhibition zone around the PCL-MA-GMi and PCL-MA-GMc samples reached 27 mm, hereby indicating a strong antibacterial effect against all types of E. coli bacteria. The GM-loaded nanofibers also demonstrated a pronounced antibacterial effect after immersion in phosphate buffered saline at 37 °C for 24 h. Thus the results demonstrated that the proposed strategy for the preparation of antibacterial biocompatible nanofibers with relatively long-term antibacterial protection has a great potential for future application for wound healing. [ABSTRACT FROM AUTHOR]

Colloidal assemblies represent a versatile and cost efficient way to generate surface patterns at micron and sub-micron length scales. Chemical modification of the assemblies can be utilized to study the influence of different surface chemistries on cellular responses with high lateral resolution. In this study, single and binary colloidal assemblies were made using different sizes of particles. An allylamine plasma polymer (ALApp) layer was deposited on the top of the assemblies to provide a uniform surface chemistry. Cellular responses toward unmodified and ALApp-coated assemblies was evaluated using L929 fibroblasts. Cells showed smaller spreading area on both single and binary assemblies compared to flat control. Cell size was dependent on the particle size or combination. This effect can be compensated by different degrees after the ALApp coating. These results will find application in the development of new cell culture coatings through the combined use of colloidal assembles and plasma polymer coatings. [ABSTRACT FROM AUTHOR]

Background: Biomaterial modifications--chemical and topographical--are of particular importance for the integration of materials in biosystems. Cells are known to sense these biomaterial characteristics, but it has remained unclear which physiological processes bio modifications trigger. Hence, the question arises of whether the dynamic of intracellular calcium ions is important for the characterization of the cell-material interaction. In our prior research we could demonstrate that a defined geometrical surface topography affects the cell physiology; this was finally detectable in a reduced intracellular calcium mobilization after the addition of adenosine triphosphate (ATP). Results: This new contribution examines the cell physiology of human osteoblasts concerning the relative cell viability and the calcium ion dynamic on different chemical modifications of silicon-titanium (Ti) substrates. Chemical modifications comprising the coating of Ti surfaces with a plasma polymerized allylamine (PPAAm)-layer or with a thin layer of collagen type-I were compared with a bare Ti substrate as well as tissue culture plastic. For this purpose, the human osteoblasts (MG-63 and primary osteoblasts) were seeded onto the surfaces for 24 h. The relative cell viability was determined by colorimetric measurements of the cell metabolism and relativized to the density of cells quantified using crystal violet staining. The calcium ion dynamic of osteoblasts was evaluated by the calcium imaging analysis of fluo-3 stained vital cells using a confocal laser scanning microscope. The positively charged nano PPAAm-layer resulted in enhanced intracellular calcium ion mobilization after ATP-stimulus and cell viability. This study underlines the importance of the calcium signaling for the manifestation of the cell physiology. Conclusions: Our current work provides new insights into the intracellular calcium dynamic caused by diverse chemical surface compositions. The calcium ion dynamic appears to be a sensitive parameter for the cell physiology and, thus, may represent a useful approach for evaluating a new biomaterial. In this regard, reliable in vitro-tests of cell behavior at the interface to a material are crucial steps in securing the success of a new biomaterial in medicine. [ABSTRACT FROM AUTHOR]

Thin films, which are able to deliver antibiotics in a controlled way, are considered as a promising approach to combat bacterial infections. A novel drug delivery method based on reservoir/diffusion barrier is introduced in this paper. As reservoir serves a film of sputtered nylon 6,6 impregnated with ampicillin, which is then covered by a diffusion barrier from the same material. It is demonstrated that the impregnation process does not affect either the morphology or the surface chemical structure. The amount of immobilized antibiotics can be tailored by changing the reservoir film thickness, while the release kinetics can be controlled by the thickness of the diffusion barrier. Finally, it is shown that the ampicillin impregnated films have an antibacterial effect against Staphylococcus epidermidis. [ABSTRACT FROM AUTHOR]

The interactions between monocytes and biomaterials can potentially be modulated by controlling the chemical and structural surface properties of biomaterials. The objective of this study was to determine the effect of plasma-deposited functional organic coatings on monocyte adhesion and differentiation into macrophages. Organic coatings with varying oxygen and nitrogen concentration were prepared by low-pressure plasma co-polymerization of binary gas mixtures combining a hydrocarbon (butadiene/ethylene) and a heteroatom-containing gas (carbon dioxide/ammonia) to deposit either oxygen or nitrogen-containing coatings. The deposition parameters controlled the composition of the coatings and, consequently, the surface charge (between 26 mV and −28 mV) and wettability. The adhesion of myeloid leukemia cell lines U937 and NB4 as well as human monocytes to plasma polymerized coatings, was tested using cell culture medium with and without fetal bovine serum. The results showed that the concentration of [-NH 2 ] and [-COOH] on the surface of the plasma polymers, controls the adhesion of U937 and NB4 cell lines to the coatings. Thus, above a certain composition threshold, i.e. [-NH 2 ]=2.6–3.0% and [-COOH]=1.2–1.57 nmol/cm 2 , the surface facilitates adhesion of both cell lines, irrespective of the culture medium used. Based on qualitative observations the number of monocytes adhering to the coatings was proportional to the concentration of functional groups at the surface of the coatings. The surface plasmon resonance results, in line with cell culture experiments, indicated that the presence of albumin on the surfaces with [-NH 2 ] and [-COOH] above the determined critical concentration may be an indicator of monocyte adhesion to these plasma polymers. [ABSTRACT FROM AUTHOR]

Plasma-polyaniline films are treated by argon plasma in order to obtain nanostructured surfaces. The polymer deposition and its subsequent treatment are realized in a low pressure microwave reactor. The effects of several operating conditions, i.e. , discharge power, argon pressure, processing time and substrate bias on the chemical and morphological structure of the obtained layers are examined. The chemical structure of the polymer is characterized using Fourier Transform Infra-Red spectroscopy whereas the film morphology is determined by Atomic Force Microscopy. The results show that the density and the dimensions of the nanostructures can be finely tuned by the plasma parameters. Low argon flow rate or microwave power, short treatment time and the use of substrate polarization yield high structured surfaces. We show that the formation of the nanodots is mainly ion-dependent according to the ion energy and the ion flux. Concerning the chemical structure of treated films, a moderate destruction of aromatic character and a partial loss of amine groups are observed. [ABSTRACT FROM AUTHOR]

The effect of ionic strength and pH on the structure of hydrated plasma polymerized films of allylamine (ppAAm) and acrylic acid (ppAAc) has been analyzed in situ using quartz crystal microbalance with dissipation techniques, electrochemical impedance spectroscopy, ellipsomtery, and X-ray photoelectron spectroscopy. Both materials showed a salt concentration and pH dependent uptake and release of water and ions. Depending on the type of monomer used, the effects showed reversible or non-reversible behavior. The investigation of the electrochemical properties of the film further revealed a non-homogeneous structure, especially in the case of ppAAc films, with regions of higher and lower cross-linking density. The use of complimentary techniques to characterize the films in situ allowed for a deeper understanding of processes happening inside the plasma polymerized films, which can help to optimize film preparation conditions for selected applications. [ABSTRACT FROM AUTHOR]