Most cited article - PubMed ID 25596482
Nano-structured and functionalized surfaces for cytocompatibility improvement and bactericidal action
The increasing prevalence of antibiotic-resistant bacteria has intensified the need for innovative antibacterial surfaces, particularly in biomedical applications. Traditional approaches often rely on chemical agents alone, which may lead to diminishing efficacy over time. To address this, we investigated the development of a novel antibacterial surface by combining the inherent antimicrobial properties of copper with an engineered surface topography on a biopolymer matrix. A copper-poly-L-lactic acid (Cu-PLLA) composite system was fabricated using sputtering deposition followed by controlled thermal treatment to induce wrinkle-like micro- and nanostructures on the surface. The surface morphology was characterized using scanning electron microscopy (SEM) and atomic force microscopy (AFM), confirming the formation of hierarchical wrinkle patterns. The chemical composition and distribution of copper were analyzed via energy-dispersive X-ray spectroscopy (EDS). Antibacterial performance was assessed against both Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus using standard colony count reduction assays. The Cu-PLLA wrinkled surfaces demonstrated significantly enhanced bactericidal activity compared with flat PLLA and copper-free controls, a finding attributed to a synergistic effect of mechanical membrane disruption and copper-mediated chemical toxicity. These findings suggest that biopolymer-metal hybrid surfaces with engineered topography offer a promising strategy for developing next-generation antibacterial materials suitable for biomedical and clinical use.
- Keywords
- antibacterial properties, biopolymer, copper composites, poly-L-lactic acid (PLLA), surface morphology, wrinkle structure,
- Publication type
- Journal Article MeSH
The construction of functional micro- or nanostructured surfaces is extensively studied since they are able to provide multifunctional properties and for large variety of potential applications in fields such as tissue engineering, wearable electronics or microfluidics. The micro- or nanosized surfaces can be easily prepared by various lithography techniques, also additional modifications (laser exposure, metal deposition and further processing) and which can induce new applicable properties on the basis of synergic effect by combining aforementioned approaches. In this work we have focused on the polytetrafluoroethylene (PTFE) nanotextile with specific bimetallic nanostructures. Our primary target was to find optimal surface modification of silver/gold coated surface, which would induce strong antibacterial response to both gram-positive and/or gram-negative bacteria. We have used plasma-modified polytetrafluoroethylene nanotextile as a substrate, onto which silver and gold nanolayers were deposited by sputtering. The foils were further subjected to "single-shot" exposure to an excimer KrF laser and some samples were also thermally stressed before exposure. Such surfaces were further examined in terms of surface morphology and chemical composition. The surface was investigated for antibacterial properties. Their antimicrobial activity was examined in vitro against the bacteria Escherichia coli and Staphylococcus epidermidis strains. The surface of the prepared materials was replicated into a lactic acid polymer and the properties were again investigated in terms of surface morphology and surface chemistry. The results demonstrated construction of antibacterial surfaces with excellent resistance to bacteria E. coli for bimetallic structures on PTFE. Excimer laser induced bimetallic pattern exhibited also significant antibacterial properties for S. epidermidis. Replication of bimetallic pattern was also demonstrated.
- Keywords
- Antibacterial properties, Bimetallic nanopattern, Laser exposure, Nanostructure, Nanotextile, Noble metal, PTFE, Polymer, Replication,
- Publication type
- Journal Article MeSH
Surface modification of various polymer foils was achieved by UV activation and chemical grafting with cysteamine to improve surface properties and antimicrobial efficacy. UVC activation at 254 nm led to changes in surface wettability and charge density, which allowed the introduction of amino and thiol functional groups by cysteamine grafting. X-ray photoelectron spectroscopy (XPS) confirmed increased nitrogen and sulfur content on the modified surfaces. SEM analysis revealed that UV activation and cysteamine grafting resulted in distinct surface roughness and texturing, which are expected to enhance microbial interactions. Antimicrobial tests showed increased resistance to algal growth (inhibition test) and bacterial colonization (drop plate method), with significant improvement observed for polyethylene terephthalate (PET) and polyetheretherketone (PEEK) foils. The important factors influencing the efficacy included UV exposure time and cysteamine concentration, with longer exposure and higher concentrations leading to bacterial reduction of up to 45.7% for Escherichia coli and 55.6% for Staphylococcus epidermidis. These findings highlight the potential of combining UV activation and cysteamine grafting as an effective method for developing polymeric materials with enhanced antimicrobial function, offering applications in industries such as healthcare and packaging.
- Keywords
- UV radiation, antimicrobial activity, chemical grafting, polymer foils, zeta potential,
- Publication type
- Journal Article MeSH
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.
- Keywords
- PDMS, coating, collagen type I, cytocompatibility, microstructure, myoblast cell, nanostructured pattern, replication, soft lithography,
- MeSH
- Cell Adhesion MeSH
- Dimethylpolysiloxanes chemistry MeSH
- Collagen * chemistry MeSH
- Myoblasts MeSH
- Mice MeSH
- Surface Properties MeSH
- Mammals MeSH
- Tissue Engineering * MeSH
- Animals MeSH
- Check Tag
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Names of Substances
- Dimethylpolysiloxanes MeSH
- Collagen * MeSH
In this review, we present a comprehensive summary of the formation of honeycomb microstructures and their applications, which include tissue engineering, antibacterial materials, replication processes or sensors. The history of the honeycomb pattern, the first experiments, which mostly involved the breath figure procedure and the improved phase separation, the most recent approach to honeycomb pattern formation, are described in detail. Subsequent surface modifications of the pattern, which involve physical and chemical modifications and further enhancement of the surface properties, are also introduced. Different aspects influencing the polymer formation, such as the substrate influence, a particular polymer or solvent, which may significantly contribute to pattern formation, and thus influence the target structural properties, are also discussed.
- Keywords
- antibacterial properties, biopolymer, breath figure, honeycomb, improved phase separation, morphology, polymer, replication, surface modification, tissue engineering,
- Publication type
- Journal Article MeSH
- Review MeSH
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.
- Keywords
- Q-carbon, Raman analysis, amorphous carbon, carbon, excimer laser, surface chemistry, surface morphology,
- Publication type
- Journal Article MeSH
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.
- Keywords
- LIPSS, cell guidance, cytocompatibility, elemental analysis, excimer laser, human cells, periodic pattern, polymer,
- MeSH
- Lasers MeSH
- Humans MeSH
- Cell Communication MeSH
- Nanostructures * chemistry MeSH
- Polymers chemistry MeSH
- Surface Properties MeSH
- Mammals MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Names of Substances
- Polymers MeSH
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.
- Keywords
- FEP, PMMA, cell adhesion, cell growth, cytocompatibility, honeycomb-like pattern, material morphology, plasma modification, polymer,
- Publication type
- Journal Article MeSH
The versatility of the arrangement of C atoms with the formation of different allotropes and phases has led to the discovery of several new structures with unique properties. Carbon nanomaterials are currently very attractive nanomaterials due to their unique physical, chemical, and biological properties. One of these is the development of superconductivity, for example, in graphite intercalated superconductors, single-walled carbon nanotubes, B-doped diamond, etc. Not only various forms of carbon materials but also carbon-related materials have aroused extraordinary theoretical and experimental interest. Hybrid carbon materials are good candidates for high current densities at low applied electric fields due to their negative electron affinity. The right combination of two different nanostructures, CNF or carbon nanotubes and nanoparticles, has led to some very interesting sensors with applications in electrochemical biosensors, biomolecules, and pharmaceutical compounds. Carbon materials have a number of unique properties. In order to increase their potential application and applicability in different industries and under different conditions, they are often combined with other types of material (most often polymers or metals). The resulting composite materials have significantly improved properties.
- Keywords
- DLC layers, Q-carbon, application, carbon, composites, graphene, modification, nanoparticles, nanostructures, thin layers,
- Publication type
- Journal Article MeSH
- Review MeSH
The subjects of this work were the enhancement and determination of the stability and other properties of gold nanoparticles (AuNPs) in an aqueous solution, gold nanoparticle immobilization, and further surface grafting on polyethylene naphthalate (PEN). Gold nanoparticles in PEG with a subsequent water solution addition were prepared using cathode sputtering; for the subsequent surface activation, two different solutions were used: (i) sodium citrate dihydrate (TCD) and (ii) N-acetyl-L-cysteine (NALC). The aim of this work was to study the effect of the concentration of these solutions on AuNPs stability, and further, the effect of the concentration of gold nanoparticles and their morphology, and to describe the aging process of solutions, namely, the optical properties of samples over 28 days. Stabilized AuNPs were prepared in an N-acetyl-L-cysteine (NALC) system and subsequently immobilized with NALC. The surface chemistry modification of AuNPs was confirmed using HRTEM/EDS. Gold nanoparticles were successfully immobilized with NALC. Grafting of the modified PEN from a solution of colloidal gold stabilized in the PEG-H2O-NALC system led to the polymer surface functionalization.
- Keywords
- grafting, nanoparticles, noble metal, plasma modification, polymer, sputtering,
- Publication type
- Journal Article MeSH