Pulsed micro-arc oxidation (MAO) in a strongly alkaline electrolyte (pH > 13), consisting of Na2SiO3⋅9H2O and NaOH, was used to form a thin porous oxide coating consisting of two layers differing in chemical and phase composition. The unique procedure, combining MAO and removal of the outer layer by blasting, enables to prepare a coating suitable for application in temporary traumatological implants. A bilayer formed in an alkaline electrolyte environment during the application of MAO enables the formation of a wear-resistant layer with silicon incorporated in the oxide phase. Following the removal of the outer rutile-containing porous layer, the required coating properties for traumatological applications were determined. The prepared surfaces were characterized by scanning electron microscopy, X-ray diffraction patterns, X-ray photoelectron spectroscopy, atomic force microscopy and contact angle measurements. Cytocompatibility was evaluated using human osteoblast-like Saos-2 cells. The newly-developed surface modifications of Ti-6Al-4V ELI alloy performed satisfactorily in all cellular tests in comparison with MAO-untreated alloy and standard tissue culture plastic. High cell viability was supported, but the modifications allowed only relatively slow cell proliferation, and showed only moderate osseointegration potential without significant support for matrix mineralization. Materials with these properties are promising for utilization in temporary traumatological implants.

• MeSH
• Electrolytes * MeSH
• Photoelectron Spectroscopy MeSH
• Humans MeSH
• Microscopy, Atomic Force MeSH
• Microscopy, Electron, Scanning MeSH
• Osseointegration physiology   MeSH
• Oxidation-Reduction MeSH
• Cell Proliferation physiology   MeSH
• Wettability * MeSH
• Cell Survival physiology   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Electrolytes * MeSH

Dermal injuries and chronic wounds usually regenerate with scar formation. Successful treatment without scarring might be achieved by pre-seeding a wound dressing with cells. We aimed to prepare a wound dressing fabricated from sodium carboxymethylcellulose (Hcel® NaT), combined with fibrin and seeded with dermal fibroblasts in vitro. We fabricated the Hcel® NaT in a porous and homogeneous form (P form and H form, respectively) differing in structural morphology and in the degree of substitution of hydroxyl groups. Each form of Hcel® NaT was functionalized with two morphologically different fibrin structures to improve cell adhesion and proliferation, estimated by an MTS assay. Fibrin functionalization of the Hcel® NaT strongly enhanced colonization of the material with human dermal fibroblasts. Moreover, the type of fibrin structures influenced the ability of the cells to adhere to the material and proliferate on it. The fibrin mesh filling the void spaces between cellulose fibers better supported cell attachment and subsequent proliferation than the fibrin coating, which only enwrapped individual cellulose fibers. On the fibrin mesh, the cell proliferation activity on day 3 was higher on the H form than on the P form of Hcel® NaT, while on the fibrin coating, the cell proliferation on day 7 was higher on the P form. The Hcel® NaT wound dressing functionalized with fibrin, especially when in the form of a mesh, can accelerate wound healing by supporting fibroblast adhesion and proliferation.

• Keywords
• dermal fibroblasts, fibrin, skin, sodium carboxymethylcellulose, wound dressing, wound healing,
• Publication type
• Journal Article MeSH

Protein-repulsive surfaces modified with ligands for cell adhesion receptors have been widely developed for controlling the cell adhesion and growth in tissue engineering. However, the question of matrix production and deposition by cells on these surfaces has rarely been addressed. In this study, protein-repulsive polydopamine-poly(ethylene oxide) (PDA-PEO) surfaces were functionalized with an RGD-containing peptide (RGD), with a collagen-derived peptide binding fibronectin (Col), or by a combination of these peptides (RGD + Col, ratio 1:1) in concentrations of 90 fmol/cm(2) and 700 fmol/cm(2) for each peptide type. When seeded with vascular endothelial CPAE cells, the PDA-PEO surfaces proved to be completely non-adhesive for cells. On surfaces with lower peptide concentrations and from days 1 to 3 after seeding, cell adhesion and growth was restored practically only on the RGD-modified surface. However, from days 3 to 7, cell adhesion and growth was improved on surfaces modified with Col and with RGD + Col. At higher peptide concentrations, the cell adhesion and growth was markedly improved on all peptide-modified surfaces in both culture intervals. However, the collagen-derived peptide did not increase the expression of fibronectin in the cells. The deposition of fibronectin on the material surface was generally very low and similar on all peptide-modified surfaces. Nevertheless, the RGD + Col surfaces exhibited the highest cell adhesion stability under a dynamic load, which correlated with the highest expression of talin and vinculin in the cells on these surfaces. A combination of RGD + Col therefore seems to be the most promising for surface modification of biomaterials, e.g. vascular prostheses.

• MeSH
• Adsorption MeSH
• Biomimetics * MeSH
• Cell Adhesion * MeSH
• Gene Expression MeSH
• Fibronectins chemistry   genetics   MeSH
• Indoles chemistry   MeSH
• Cells, Cultured MeSH
• Humans MeSH
• Molecular Sequence Data MeSH
• Oligopeptides chemistry   MeSH
• Polyethylene Glycols chemistry   MeSH
• Polymers chemistry   MeSH
• Surface Properties MeSH
• Amino Acid Sequence MeSH
• Talin genetics   MeSH
• Vinculin genetics   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Fibronectins MeSH
• Indoles MeSH
• Oligopeptides MeSH
• polydopamine MeSH Browser
• Polyethylene Glycols MeSH
• Polymers MeSH
• Talin MeSH
• Vinculin MeSH

Cell colonization of synthetic polymers can be regulated by physical and chemical modifications of the polymer surface. High-density and low-density polyethylene (HDPE and LDPE) were therefore activated with Ar⁺ plasma and grafted with fibronectin (Fn) or bovine serum albumin (BSA). The water drop contact angle usually decreased on the plasma-treated samples, due to the formation of oxidized groups, and this decrease was inversely related to the plasma exposure time (50-300 s). The presence of nitrogen and sulfur on the polymer surface, revealed by X-ray photoelectron spectroscopy (XPS), and also by immunofluorescence staining, showed that Fn and BSA were bound to this surface, particularly to HDPE. Plasma modification and grafting with Fn and BSA increased the nanoscale surface roughness of the polymer. This was mainly manifested on HDPE. Plasma treatment and grafting with Fn or BSA improved the adhesion and growth of vascular smooth muscle cells in a serum-supplemented medium. The final cell population densities on day 6 after seeding were on an average higher on LDPE than on HDPE. In a serum-free medium, BSA grafted to the polymer surface hampered cell adhesion. Thus, the cell behavior on polyethylene can be modulated by its type, intensity of plasma modification, grafting with biomolecules, and composition of the culture medium.

• Keywords
• albumin, bioactivity, biocompatibility, cell spreading area, fibronectin, nanoscale surface roughness, plasma treatment, tissue engineering, wettability,
• Publication type
• Journal Article MeSH

The attractiveness of synthetic polymers for cell colonization can be affected by physical, chemical, and biological modification of the polymer surface. In this study, low-density polyethylene (LDPE) was treated by an Ar(+) plasma discharge and then grafted with biologically active substances, namely, glycine (Gly), polyethylene glycol (PEG), bovine serum albumin (BSA), colloidal carbon particles (C), or BSA+C. All modifications increased the oxygen content, the wettability, and the surface free energy of the materials compared to the pristine LDPE, but these changes were most pronounced in LDPE with Gly or PEG, where all the three values were higher than in the only plasma-treated samples. When seeded with vascular smooth muscle cells (VSMCs), the Gly- or PEG-grafted samples increased mainly the spreading and concentration of focal adhesion proteins talin and vinculin in these cells. LDPE grafted with BSA or BSA+C showed a similar oxygen content and similar wettability, as the samples only treated with plasma, but the nano- and submicron-scale irregularities on their surface were more pronounced and of a different shape. These samples promoted predominantly the growth, the formation of a confluent layer, and phenotypic maturation of VSMC, demonstrated by higher concentrations of contractile proteins alpha-actin and SM1 and SM2 myosins. Thus, the behavior of VSMC on LDPE can be regulated by the type of bioactive substances that are grafted.

• MeSH
• Aorta cytology   drug effects   MeSH
• Biocompatible Materials chemistry   pharmacology   MeSH
• Cell Adhesion drug effects   MeSH
• Glycine chemistry   pharmacology   MeSH
• Rats MeSH
• Cells, Cultured MeSH
• Myocytes, Smooth Muscle cytology   drug effects   MeSH
• Polyethylene chemistry   pharmacology   MeSH
• Polyethylene Glycols chemistry   pharmacology   MeSH
• Surface Properties MeSH
• Cell Proliferation drug effects   MeSH
• Serum Albumin, Bovine chemistry   pharmacology   MeSH
• Muscle, Smooth, Vascular cytology   drug effects   MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Biocompatible Materials MeSH
• Glycine MeSH
• Polyethylene MeSH
• Polyethylene Glycols MeSH
• Serum Albumin, Bovine MeSH

Intrinsic nanocrystalline diamond (NCD) films have been proven to be promising substrates for the adhesion, growth and osteogenic differentiation of bone-derived cells. To understand the role of various degrees of doping (semiconducting to metallic-like), the NCD films were deposited on silicon substrates by a microwave plasma-enhanced CVD process and their boron doping was achieved by adding trimethylboron to the CH(4):H(2) gas mixture, the B∶C ratio was 133, 1000 and 6700 ppm. The room temperature electrical resistivity of the films decreased from >10 MΩ (undoped films) to 55 kΩ, 0.6 kΩ, and 0.3 kΩ (doped films with 133, 1000 and 6700 ppm of B, respectively). The increase in the number of human osteoblast-like MG 63 cells in 7-day-old cultures on NCD films was most apparent on the NCD films doped with 133 and 1000 ppm of B (153,000 ± 14,000 and 152,000 ± 10,000 cells/cm(2), respectively, compared to 113,000 ± 10,000 cells/cm(2) on undoped NCD films). As measured by ELISA per mg of total protein, the cells on NCD with 133 and 1000 ppm of B also contained the highest concentrations of collagen I and alkaline phosphatase, respectively. On the NCD films with 6700 ppm of B, the cells contained the highest concentration of focal adhesion protein vinculin, and the highest amount of collagen I was adsorbed. The concentration of osteocalcin also increased with increasing level of B doping. The cell viability on all tested NCD films was almost 100%. Measurements of the concentration of ICAM-1, i.e. an immunoglobuline adhesion molecule binding inflammatory cells, suggested that the cells on the NCD films did not undergo significant immune activation. Thus, the potential of NCD films for bone tissue regeneration can be further enhanced and tailored by B doping and that B doping up to metallic-like levels is not detrimental for cells.

• MeSH
• Adsorption MeSH
• Boron chemistry   MeSH
• Cell Adhesion drug effects   MeSH
• Cell Differentiation drug effects   MeSH
• Cell Line MeSH
• Diamond chemistry   pharmacology   MeSH
• Physical Phenomena MeSH
• Collagen Type I chemistry   MeSH
• Silicon chemistry   MeSH
• Humans MeSH
• Nanostructures chemistry   MeSH
• Osteoblasts cytology   drug effects   immunology   MeSH
• Osteogenesis drug effects   MeSH
• Semiconductors MeSH
• Cell Proliferation drug effects   MeSH
• Cell Survival drug effects   MeSH
• Dose-Response Relationship, Drug MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Boron MeSH
• Diamond MeSH
• Collagen Type I MeSH
• Silicon MeSH

High-density polyethylene (PE) foils were modified by an Ar(+) plasma discharge and subsequent grafting with biomolecules, namely glycine (Gly), polyethylene glycol (PEG), bovine serum albumin (BSA), colloidal carbon particles (C) or BSA and C (BSA + C). As revealed by atomic force microscopy (AFM), goniometry and Rutherford Backscattering Spectroscopy (RBS), the surface chemical structure and surface morphology of PE changed dramatically after plasma treatment. The contact angle decreased for the samples treated by plasma, mainly in relation to the formation of oxygen structures during plasma irradiation. A further decrease in the contact angle was obvious after glycine and PEG grafting. The increase in oxygen concentration after glycine and PEG grafting proved that the two molecules were chemically linked to the plasma-activated surface. Plasma treatment led to ablation of the PE surface layer, thus the surface morphology was changed and the surface roughness was increased. The materials were then seeded with vascular smooth muscle cells (VSMC) derived from rat aorta and incubated in a DMEM medium with fetal bovine serum. Generally, the cells adhered and grew better on modified rather than on unmodified PE samples. Immunofluorescence showed that focal adhesion plaques containing talin, vinculin and paxillin were most apparent in cells on PE grafted with PEG or BSA + C, and the fibres containing alpha-actin, beta-actin or SM1 and SM2 myosins were thicker, more numerous and more brightly stained in the cells on all modified PE samples than on pristine PE. An enzyme-linked immunosorbent assay (ELISA) revealed increased concentrations of focal adhesion proteins talin and vinculin and also a cytoskeletal protein beta-actin in cells on PE modified with BSA + C. A contractile protein alpha-actin was increased in cells on PE grafted with PEG or Gly. These results showed that PE activated with plasma and subsequently grafted with bioactive molecules and colloidal C particles, especially with PEG and BSA + C, promotes the adhesion, proliferation and phenotypic maturation of VSMC.

• Keywords
• bioactivity, biocompatibility, plasma irradiation, tissue engineering and reconstruction,
• MeSH
• Actins metabolism   MeSH
• Aorta cytology   MeSH
• Cell Adhesion drug effects   MeSH
• Glycine pharmacology   MeSH
• Rats MeSH
• Cells, Cultured MeSH
• Oxygen metabolism   MeSH
• Microscopy, Atomic Force MeSH
• Polyethylene chemistry   pharmacology   MeSH
• Polyethylene Glycols chemistry   pharmacology   MeSH
• Cell Proliferation drug effects   MeSH
• Serum Albumin, Bovine pharmacology   MeSH
• Cattle MeSH
• Muscle, Smooth, Vascular cytology   drug effects   metabolism   MeSH
• Carbon chemistry   MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Cattle MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Actins MeSH
• Glycine MeSH
• Oxygen MeSH
• Polyethylene MeSH
• Polyethylene Glycols MeSH
• Serum Albumin, Bovine MeSH
• Carbon MeSH