We investigated the use of a supported silicalite-1 film (SF) as a promising coating for metallic materials used in the fabrication of prostheses. The role of carbonaceous residua present on high-temperature calcined-SF in generating singlet oxygen for future use as a sterilization method has also been addressed, and the potential genotoxicity of these residua in osteoblast-like cells has been investigated. Calcination of as-synthesized SF induced the appearance of a rather complicated mixture of aliphatic and aromatic species on its outer surface. A series of variously volatile polycyclic aromatic hydrocarbons (PAH), including naphthalene, fluorene, phenanthrene, anthracene, fluoranthene, and pyrene, were identified in micromole concentrations. Irradiation of these PAHs on calcined-SF immersed in air-saturated chloroform led to the formation of very low concentrations of singlet oxygen. However, an increased level of DNA damage was observed on calcined-SF by immunofluorescence staining of phosphorylated histone H2AX analyzed by flow cytometry.

• Keywords
• genotoxicity, implant material, singlet oxygen, surface coating,
• Publication type
• Journal Article MeSH

Thin films of binary C60/Ti composites, with various concentrations of Ti ranging from ~ 25% to ~ 70%, were deposited on microscopic glass coverslips and were tested for their potential use in bone tissue engineering as substrates for the adhesion and growth of bone cells. The novelty of this approach lies in the combination of Ti atoms (i.e., widely used biocompatible material for the construction of stomatological and orthopedic implants) with atoms of fullerene C60, which can act as very efficient radical scavengers. However, fullerenes and their derivatives are able to generate harmful reactive oxygen species and to have cytotoxic effects. In order to stabilize C60 molecules and to prevent their possible cytotoxic effects, deposition in the compact form of Ti/C60 composites (with various Ti concentrations) was chosen. The reactivity of C60/Ti composites may change in time due to the physicochemical changes of molecules in an air atmosphere. In this study, we therefore tested the dependence between the age of C60/Ti films (from one week to one year) and the adhesion, morphology, proliferation, viability, metabolic activity and potential DNA damage to human osteosarcoma cells (lines MG-63 and U-2 OS). After 7 days of cultivation, we did not observe any negative influence of fresh or aged C60/Ti layers on cell behavior, including the DNA damage response. The presence of Ti atoms resulted in improved properties of the C60 layers, which became more suitable for cell cultivation.

• MeSH
• Cell Adhesion drug effects   MeSH
• Time Factors MeSH
• Fullerenes chemistry   pharmacology   MeSH
• Humans MeSH
• Cell Line, Tumor MeSH
• Osteoblasts cytology   drug effects   metabolism   MeSH
• DNA Damage MeSH
• Cell Proliferation drug effects   MeSH
• Reactive Oxygen Species antagonists & inhibitors   metabolism   MeSH
• Titanium chemistry   pharmacology   MeSH
• Tissue Engineering MeSH
• Tissue Scaffolds * MeSH
• Cell Survival drug effects   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• fullerene C60 MeSH Browser
• Fullerenes MeSH
• Reactive Oxygen Species MeSH
• Titanium MeSH

An investigation was made of the adhesion, growth and differentiation of osteoblast-like MG-63 and Saos-2 cells on titanium (Ti) and niobium (Nb) supports and on TiNb alloy with surfaces oxidized at 165°C under hydrothermal conditions and at 600°C in a stream of air. The oxidation mode and the chemical composition of the samples tuned the morphology, topography and distribution of the charge on their surfaces, which enabled us to evaluate the importance of these material characteristics in the interaction of the cells with the sample surface. Numbers of adhered MG-63 and Saos-2 cells correlated with the number of positively-charged (related with the Nb2O5 phase) and negatively-charged sites (related with the TiO2 phase) on the alloy surface. Proliferation of these cells is correlated with the presence of positively-charged (i.e. basic) sites of the Nb2O5 alloy phase, while cell differentiation is correlated with negatively-charged (acidic) sites of the TiO2 alloy phase. The number of charged sites and adhered cells was substantially higher on the alloy sample oxidized at 600°C than on the hydrothermally treated sample at 165°C. The expression values of osteoblast differentiation markers (collagen type I and osteocalcin) were higher for cells grown on the Ti samples than for those grown on the TiNb samples. This was more particularly apparent in the samples treated at 165°C. No considerable immune activation of murine macrophage-like RAW 264.7 cells on the tested samples was found. The secretion of TNF-α by these cells into the cell culture media was much lower than for either cells grown in the presence of bacterial lipopolysaccharide, or untreated control samples. Thus, oxidized Ti and TiNb are both promising materials for bone implantation; TiNb for applications where bone cell proliferation is desirable, and Ti for induction of osteogenic cell differentiation.

• MeSH
• Biomarkers metabolism   MeSH
• Cell Adhesion drug effects   MeSH
• Cell Differentiation drug effects   MeSH
• Cell Line MeSH
• Collagen Type I metabolism   MeSH
• Humans MeSH
• Lipopolysaccharides pharmacology   MeSH
• Macrophages cytology   drug effects   metabolism   MeSH
• Mice MeSH
• Osteoblasts cytology   drug effects   metabolism   MeSH
• Osteocalcin metabolism   MeSH
• Oxidation-Reduction MeSH
• Surface Properties MeSH
• Cell Proliferation drug effects   MeSH
• Alloys chemistry   pharmacology   MeSH
• Static Electricity MeSH
• Tissue Scaffolds * MeSH
• Tumor Necrosis Factor-alpha pharmacology   MeSH
• Hot Temperature MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Mice MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Biomarkers MeSH
• Collagen Type I MeSH
• Lipopolysaccharides MeSH
• Osteocalcin MeSH
• Alloys MeSH
• titanium-niobium alloy MeSH Browser
• Tumor Necrosis Factor-alpha MeSH

BACKGROUND: Nanofibrous scaffolds loaded with bioactive nanoparticles are promising materials for bone tissue engineering. METHODS: In this study, composite nanofibrous membranes containing a copolymer of L-lactide and glycolide (PLGA) and diamond nanoparticles were fabricated by an electrospinning technique. PLGA was dissolved in a mixture of methylene chloride and dimethyl formamide (2:3) at a concentration of 2.3 wt%, and nanodiamond (ND) powder was added at a concentration of 0.7 wt% (about 23 wt% in dry PLGA). RESULTS: In the composite scaffolds, the ND particles were either arranged like beads in the central part of the fibers or formed clusters protruding from the fibers. In the PLGA-ND membranes, the fibers were thicker (diameter 270 ± 9 nm) than in pure PLGA meshes (diameter 218 ± 4 nm), but the areas of pores among these fibers were smaller than in pure PLGA samples (0.46 ± 0.02 μm(2) versus 1.28 ± 0.09 μm(2) in pure PLGA samples). The PLGA-ND membranes showed higher mechanical resistance, as demonstrated by rupture tests of load and deflection of rupture probe at failure. Both types of membranes enabled the attachment, spreading, and subsequent proliferation of human osteoblast-like MG-63 cells to a similar extent, although these values were usually lower than on polystyrene dishes. Nevertheless, the cells on both types of membranes were polygonal or spindle-like in shape, and were distributed homogeneously on the samples. From days 1-7 after seeding, their number rose continuously, and at the end of the experiment, these cells were able to create a confluent layer. At the same time, the cell viability, evaluated by a LIVE/DEAD viability/cytotoxicity kit, ranged from 92% to 97% on both types of membranes. In addition, on PLGA-ND membranes, the cells formed well developed talin-containing focal adhesion plaques. As estimated by the determination of tumor necrosis factor-alpha levels in the culture medium and concentration of intercellular adhesion molecule-1, MG-63 cells, and RAW 264.7 macrophages on these membranes did not show considerable inflammatory activity. CONCLUSION: This study shows that nanofibrous PLGA membranes loaded with diamond nanoparticles have interesting potential for use in bone tissue engineering.

• Keywords
• electrospinning, human bone cells, nanofibers, nanoparticles, nanotechnology, regenerative medicine,
• MeSH
• Cell Adhesion MeSH
• Cell Line MeSH
• Diamond chemistry   MeSH
• Polylactic Acid-Polyglycolic Acid Copolymer MeSH
• Bone Substitutes chemistry   MeSH
• Lactic Acid chemistry   MeSH
• Polyglycolic Acid chemistry   MeSH
• Humans MeSH
• Actin Cytoskeleton metabolism   MeSH
• Microscopy, Electron, Scanning MeSH
• Mice MeSH
• Nanoparticles chemistry   ultrastructure   MeSH
• Nanomedicine MeSH
• Nanofibers chemistry   ultrastructure   MeSH
• Osteoblasts cytology   immunology   physiology   MeSH
• Cell Proliferation MeSH
• Materials Testing MeSH
• Tissue Engineering methods   MeSH
• Tissue Scaffolds chemistry   MeSH
• Microscopy, Electron, Transmission MeSH
• Cell Survival MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Mice MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Diamond MeSH
• Polylactic Acid-Polyglycolic Acid Copolymer MeSH
• Bone Substitutes MeSH
• Lactic Acid MeSH
• Polyglycolic Acid 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