PubMed | Swerea IVF AB, Polytechnic University of Turin, NTTF Coatings GmbH, Albert Ludwigs University of Freiburg and MOESCHTER GROUP Holding GmbH & Co. KG
Type: | Journal: Dental materials : official publication of the Academy of Dental Materials | Year: 2017
To adequately address clinically important issues such as osseointegration and soft tissue integration, we screened for the direct biological cell response by culturing human osteoblasts and gingival fibroblasts on novel zirconia-based dental implant biomaterials and subjecting them to transcriptional analysis.Biomaterials used for osteoblasts involved micro-roughened surfaces made of a new type of ceria-stabilized zirconia composite with two different topographies, zirconium dioxide, and yttria-stabilized zirconia (control). For fibroblasts smooth ceria- and yttria-stabilized zirconia surface were used. The expression of 90 issue-relevant genes was determined on mRNA transcription level by real-time PCR Array technology after growth periods of 1 and 7 days.Generally, modulation of gene transcription exhibited a dual dependence, first by time and second by the biomaterial, whereas biomaterial-triggered changes were predominantly caused by the biomaterials chemistry rather than surface topography. Per se, modulated genes assigned to regenerative tissue processes such as fracture healing and wound healing and in detail included colony stimulating factors (CSF2 and CSF3), growth factors, which regulate bone matrix properties (e.g. BMP3 and TGFB1), osteogenic BMPs (BMP2/4/6/7) and transcription factors (RUNX2 and SP7), matrix collagens and osteocalcin, laminins as well as integrin 1 and MMP-2.With respect to the biomaterials under study, the screening showed that a new zirconia-based composite stabilized with ceria may be promising to provide clinically desired periodontal tissue integration. Moreover, by detecting biomarkers modulated in a time- and/or biomaterial-dependent manner, we identified candidate genes for the targeted analysis of cell-implant bioresponse during biomaterial research and development.
Agency: European Commission | Branch: FP7 | Program: CP-TP | Phase: NMP.2011.2.1-1 | Award Amount: 5.56M | Year: 2012
The aim of LONGLIFE is to develop new multi-functional zirconia oral and spine (lumbar inter-vertebral disc) implants, with a perfect reliability and a lifetime longer than 60 years. Such an ambitious goal, motivated by the risks and costs associated to revision surgery, will only be reachable by an improvement of the Low Temperature Degradation (LTD) resistance of zirconia and by an enhancement of the osseointegration capabilities of the implants in contact with bone. As zirconia-based ceramics are the only oxides able to couple high stress resistance and fracture toughness thanks to transformation toughening, a strong effort will be given to the improvement of their stability in the presence of water, without decreasing their toughness and strength. Osseointegration will be improved by the chemical and topographical modification of the surface. We aim at producing zirconia surfaces able to decrease the risk of bacterial adhesion and improve bone apposition, for better clinical success. Given the specific nature of ceramics, especially versus the risk of brittle failure, we aim at developing new ceramic-oriented designs for the implants, and not just copy and paste from metal implants as it is generally done at present. This implants by design approach will ensure a better, long-lasting success of oral and spine implants. At last, the LONGLIFE consortium will develop acceleration tests which will be able to reproduce more effectively the different degradation mechanisms and their interplay in a multi-physics approach, in order to ensure an implant reliability and lifetime superior to current implants.
PubMed | Polytechnic University of Turin, NTTF Coatings GmbH, Albert Ludwigs University of Freiburg, University Claude Bernard Lyon 1 and 2 more.
Type: Journal Article | Journal: Clinical oral investigations | Year: 2016
Biomaterial surfaces are at high risk for initial microbial colonization, persistence, and concomitant infection. The rationale of this study was to assess the initial adhesion on novel implant surfaces of Enterococcus faecalis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans upon incubation.The tested samples were 3mol% yttria-stabilized tetragonal zirconia polycrystal (3Y-TZP) samples with nitrogen-doped hydrogenated amorphous carbon (a-C:H:N) coating (A) and 3Y-TZP samples coated with ceria-stabilized zirconia-based (Ce-TZP) composite and a-C:H:N (B). Uncoated 3Y-TZP samples (C) and bovine enamel slabs (BES) served as controls. Once the surface was characterized, the adherent microorganisms were quantified by estimating the colony-forming units (CFUs). Microbial vitality was assessed by live/dead staining, and microbial-biomaterial surface topography was visualized by scanning electron microscopy (SEM).Overall, A and B presented the lowest CFU values for all microorganisms, while C sheltered significantly less E. faecalis, P. aeruginosa, and C. albicans than BES. Compared to the controls, B demonstrated the lowest vitality values for E. coli (54.12%) and C. albicans (67.99%). Interestingly, A (29.24 %) exhibited higher eradication rates for S. aureus than B (13.95%).Within the limitations of this study, a-C:H:N-coated 3Y-TZP surfaces tended to harbor less initially adherent microorganisms and selectively interfered with their vitality.This could enable further investigation of the new multi-functional zirconia surfaces to confirm their favorable antimicrobial properties in vivo.
Laube N.,Deutsches Harnsteinzentrum |
Klein F.,FH Aachen |
Bernsmann F.,NTTF Coatings GmbH
Urolithiasis | Year: 2016
It is routinely observed that persons with increased urinary stone risk factors do not necessarily form uroliths. Furthermore, stone formers can present with urinalyses that do not reflect the clinical picture. We explain this discrepancy by differences in crystallization kinetics. In 1162 urines, crystallization of Ca-oxalate was induced according to the BONN-Risk-Index (BRI) method. The urine’s relative light transmissivity (RLT) was recorded from 100 % at start of titration to 95 % due to nuclei formation and crystal growth. From the RLT changes, a measure of the thermodynamic inhibition threshold of crystal formation (BRI) and of crystal growth kinetics is derived (“turbidity slope” after crystallization onset). On average, subjects presenting with a low inhibition threshold, i.e., high BRI, also present significantly higher crystal growth rates compared with subjects in lower BRI classes. Only subjects in the highest BRI class show a lower growth rate than expected, probably due to a depletion of supersaturation by massive initial nucleation. With increasing thermodynamic risk of crystal formation (i.e., increasing BRI) due to an imbalance between inhibitors and promoters of crystal formation, an increase in the imbalance between inhibitors and promoters of crystal growth (i.e., increasing growth rate) is observed. Both lead to an increased urolith formation risk. Healthy subjects with increased BRI are an exception to this trend: their urine is thermodynamically prone to form stones, but they show a kinetic inhibition preventing nuclei from significant growth. © 2016 Springer-Verlag Berlin Heidelberg
Bernsmann F.,NTTF Coatings GmbH |
Laube N.,NTTF Coatings GmbH |
Baldsiefen G.,University of Kaiserslautern |
Castellucci M.,University of Trieste
Journal of Physics: Conference Series | Year: 2014
Inflammations and crystalline bacterial biofilms (encrustations) remain a major complication in long-term artificial urinary tract drainage. To solve this problem we present urological implants with coatings made of amorphous hydrogenated carbon (a-C:H) that show excellent protection from encrustation in-vitro as well as in-vivo. Part of the success of a-C:H coatings is attributed to their ability to act as a diffusion barrier between an implant and the body, which prevents leaching of solvents from polymeric implants. To further enhance their barrier properties a-C:H coatings are combined with parylene coatings to develop diffusion-barrier multilayer coatings with a total thickness between 0.2 μm and 0.8 μm. The combination of the two types of coatings leads to a reduction of water diffusion by a factor of up to ten with respect to uncoated 25 μm thick polyimide sub-strates. The diffusion of water vapour from a controlled atmospheric pressure chamber through coated foils to a vacuum chamber is measured in a custom-built device. © Published under licence by IOP Publishing Ltd.
Daylight photocatalytically active coatings for hospital equipment and medical products for improved hygienic safety [Bei Tageslicht photokatalytisch aktive Beschichtungen für Klinikausstattungen und Medizinprodukte zur Erhöhung der Hygienesicherheit]
Laube N.,Deutsches Harnsteinzentrum |
Bernsmann F.,NTTF Coatings GmbH
Hygiene + Medizin | Year: 2012
Background: Crystalline titanium dioxide shows photocatalysis when exposed to ultraviolet (UV) light. The radical species produced by photocatalysis decompose chemical bonds of adsorbed organic matter. Cellular membranes of all kinds of microorganisms and spores are attacked and inactivated; this holds also true for antibioticresistant bacterial strains. Method: This report introduces the plasmadeposited titanium dioxide coating "TiX" of only a few hundreds of nanometres thickness, which can be conformally deposited on arbitrary substrates to give them the abovementioned photoinduced properties. Results: It is shown that the small UV fraction of daylight is already sufficient to photocatalytically decompose microorganisms (test species: Kocuria rhizophila). TiX coatings are very hydrophilic even without photoactivation. Their hydrophilic character, which can be further enhanced by light exposure, facilitates cleaning, because water can undermine pollutants to remove them. Conclusion: Due to their properties, TiX coatings can increase the general hygienic status by decreasing the risk of infection as a reliable and durable add-on to surfaces presenting hygienic risks.
Alami J.,INI coatings LTD |
Alami J.,CAS Shanghai Institute of Ceramics |
Maric Z.,INI coatings LTD |
Busch H.,NTTF coatings GmbH |
And 3 more authors.
Surface and Coatings Technology | Year: 2014
High power pulsed magnetron sputtering (HIPIMS) is a technical description of a coating approach that utilizes enhanced ionized sputtering. HIPIMS pulsing can be performed in a large number of ways resulting in widely different plasma conditions, causing inconsistency and lack of repeatability of results. The present paper discusses this issue and suggests two important parameters that, once defined, could bring more consistency to the HIPIMS process, namely magnetic field strength and unbalance, and pulsing configuration. As illustrative examples, the effects of the pulsing and the magnetic field configurations on the growth and the properties of CrN coatings are presented. The methodology used to optimize the HIPIMS conditions is then implemented during the deposition of TiN for hard coating applications, which are then compared to state-of-the-arc arc evaporated TiN. It is shown that application-specific process-designed HIPIMS can result in superior coatings. The paper argues that the proper use of HIPIMS could only be when the sought results as well as the HIPIMS configuration are well defined. © 2013 Elsevier B.V.
Laube N.,NTTF Coatings GmbH |
Desai C.,NTTF Coatings GmbH |
Bernsmann F.,NTTF Coatings GmbH
Biomedizinische Technik | Year: 2016
Current discussions about biofilm formation focus on the solid/liquid interface between a medical device and body fluids. Yet it has been shown that gas bubbles (GB) can stably form on ureteral stents in artificial urine and that their fate depends on the stent's surface properties. The liquid/gas interface constitutes an adhesion site for precipitating salts as well as hydrophobic organic molecules. The surface wettability of polyurethane stents is varied by coating with amorphous hydrogenated carbon (a-C:H). GB and crystalline biofilm formation on the stents are investigated in a novel encrustation device which avoids gravitation-or sample-position-related influences on the results. Bigger and more stable GB form on hydrophobic stents than on hydrophilic, coated stents. Appearance and amount of crystalline deposits differ significantly between the surfaces. With decreasing wettability the number of hollow crystalline spheres and the mass of precipitate increase. On hydrophobic surfaces, stable GB increase precipitation of salts and become incorporated in the growing encrustation layer in vitro. In contrast, GB quickly lift off from hydrophilic surfaces taking part of the precipitate with them. This self-cleaning mechanism slows down the encrustation process. A similar effect may explain the prolonged complication-free indwelling time of amorphous-carbon coated stents in vivo. © 2016 Walter de Gruyter GmbH, Berlin/Boston.
PubMed | NTTF Coatings GmbH, Deutsches Harnsteinzentrum and Universitatsklinikum Bonn
Type: | Journal: SpringerPlus | Year: 2015
Placement of ureteral stents (DJ-stents) may lead to complications. Inappropriate friction properties of the implant are, inter alia, made responsible for primary injuries, injury-related inflammation and a cascade of consecutive side effects. Hydrophilicity is considered to be related to low friction. The question arises, whether the various products on the market show their respective maximum hydrophilicity directly after unwrapping or a pre-use moistening, as already routinely done with the guide wire, is necessary.The surface wettability of commercial and experimental DJ-stents was determined by water contact angle (WCA) measurements using the sessile drop method. One reference surface and 11 different stent surface types were tested. In order to determine the influence of moistening on the stents surface wettability, WCAs were measured twice, with dry, and soaked (30min, 0.9%-NaCl) specimens. Each sample of a surface type was tested at three different positions to avoid effects of surface heterogeneities. Up to six samples of the same surface type were examined.Mean WCAs on fresh and soaked stent surfaces ranged from 75-103 and 71-99. In every case the WCAs on soaked surfaces were lower. On average the WCAs decrease by 7%, the individual decreases differ considerably, from 2 to 16%. For 7/12 of the examined surface types, the decrease in contact angle is statistically significant with p0.01.DJ-stents freshly unwrapped show less hydrophilic properties compared to DJ-stents soaked in saline. To obtain maximum hydrophilicity at stent placement, DJ-stents should be soaked. The results may advocate a similar approach for other urological equipment.
PubMed | NTTF Coatings GmbH, Deutsches Harnsteinzentrum and FH Aachen
Type: | Journal: Urolithiasis | Year: 2016
It is routinely observed that persons with increased urinary stone risk factors do not necessarily form uroliths. Furthermore, stone formers can present with urinalyses that do not reflect the clinical picture. We explain this discrepancy by differences in crystallization kinetics. In 1162 urines, crystallization of Ca-oxalate was induced according to the BONN-Risk-Index (BRI) method. The urines relative light transmissivity (RLT) was recorded from 100% at start of titration to 95% due to nuclei formation and crystal growth. From the RLT changes, a measure of the thermodynamic inhibition threshold of crystal formation (BRI) and of crystal growth kinetics is derived (turbidity slope after crystallization onset). On average, subjects presenting with a low inhibition threshold, i.e., high BRI, also present significantly higher crystal growth rates compared with subjects in lower BRI classes. Only subjects in the highest BRI class show a lower growth rate than expected, probably due to a depletion of supersaturation by massive initial nucleation. With increasing thermodynamic risk of crystal formation (i.e., increasing BRI) due to an imbalance between inhibitors and promoters of crystal formation, an increase in the imbalance between inhibitors and promoters of crystal growth (i.e., increasing growth rate) is observed. Both lead to an increased urolith formation risk. Healthy subjects with increased BRI are an exception to this trend: their urine is thermodynamically prone to form stones, but they show a kinetic inhibition preventing nuclei from significant growth.