Search results for "implants"
showing 10 items of 505 documents
Dynamic In Vivo Biocompatibility of Angiogenic Peptide Amphiphile Nanofibers
2009
Biomaterials that promote angiogenesis have great potential in regenerative medicine for rapid revascularization of damaged tissue, survival of transplanted cells, and healing of chronic wounds. Supramolecular nanofibers formed by self-assembly of a heparin-binding peptide amphiphile and heparan sulfate-like glycosaminoglycans were evaluated here using a dorsal skinfold chamber model to dynamically monitor the interaction between the nanofiber gel and the microcirculation, representing a novel application of this model. We paired this model with a conventional subcutaneous implantation model for static histological assessment of the interactions between the gel and host tissue. In the stati…
Toward potent antibiofilm degradable medical devices: A generic method for the antibacterial surface modification of polylactide
2013
International audience; The effects of biomaterials on their environment must be carefully modulated in most biomedical applications. Among other approaches, this modulation can be obtained through the modification of the biomaterial surface. This paper proposes a simple and versatile strategy to produce non-leaching antibacterial polylactide (PLA) surfaces without any degradation of the polyester chains. The method is based on a one-pot procedure that provides a "clickable" PLA surface via anionic activation which is then functionalized with an antibacterial quaternized poly(2-(dimethylamino)ethyl methacrylate) (QPDMAEMA) by covalent immobilization on the surface. The anti-adherence and an…
Response of human endothelial cells to oxidative stress on Ti6Al4V alloy.
2007
Titanium and its alloys are amongst the most frequently used materials in bone and dental implantology. The good biocompatibility of titanium(-alloys) is attributed to the formation of a titanium oxide layer on the implant surface. However, implant failures do occur and this appears to be due to titanium corrosion. Thus, cells participating in the wound healing processes around an implanted material, among them endothelial cells, might be subjected to reactive oxygen species (ROS) formed by electrochemical processes during titanium corrosion. Therefore, we studied the response of endothelial cells grown on Ti6Al4V alloy to H(2)O(2) and compared this with the response of endothelial cells gr…
Histological and histomorphometrical analysis of a silica matrix embedded nanocrystalline hydroxyapatite bone substitute using the subcutaneous impla…
2010
The clinical suitability of a bone substitute material is determined by the ability to induce a tissue reaction specific to its composition. The aim of this in vivo study was to analyze the tissue reaction to a silica matrix-embedded, nanocrystalline hydroxyapatite bone substitute. The subcutaneous implantation model in Wistar rats was chosen to assess the effect of silica degradation on the vascularization of the biomaterial and its biodegradation within a time period of 6 months. Already at day 10 after implantation, histomorphometrical analysis showed that the vascularization of the implantation bed reached its peak value compared to all other time points. Both vessel density and vascula…
Calcium phosphate/polyvinyl acetate coatings on SS304 via galvanic co-deposition for orthopedic implant applications
2021
Abstract In this work, the galvanic deposition method is used to deposit coatings of brushite/hydroxyapatite/polyvinyl acetate on 304 stainless steel. Coatings are obtained at different temperatures and with different sacrificial anodes, consisting of a mixture of brushite and hydroxyapatite. Samples are aged in a simulated body fluid (SBF), where a complete conversion of brushite into hydroxyapatite with a simultaneous change in morphology and wettability occurred. The corrosion tests show that, compared with bare 304, the coating shifts Ecorr to anodic values and reduces icorr Ecorr, and icorr has different values at different aging times due to chemical interactions at the solid/liquid i…
Repeatability of the resonance frequency analysis values in implants with a new technology
2019
Background Assess the reliability (by means of reproducibility and repeatability) of the PenguinRFA system, analyse the ISQ values of different implant types and correlate the ISQ with the insertion torque during the placement of the implant. Material and Methods 120 rough surface implants were placed in bovine bone (type II and III). The implants were divided into groups, according to its design. Once the implants were in place, the exact insertion torque was registered. Then, primary stability was measured by means of the resonance frequency analysis with the PenguinRFA and the Osstell ISQ devices. In each implant two transducers of each device were used. Three measurements were obtained …
Implantable Sensors Based on Gold Nanoparticles for Continuous Long-Term Concentration Monitoring in the Body.
2021
Implantable sensors continuously transmit information on vital values or biomarker concentrations in bodily fluids, enabling physicians to survey disease progression and monitor therapeutic success. However, currently available technologies still face difficulties with long-term operation and transferability to different analytes. We show the potential of a generalizable platform based on gold nanoparticles embedded in a hydrogel for long-term implanted biosensing. Using optical imaging and an intelligent sensor/reference-design, we assess the tissue concentration of kanamycin in anesthetized rats by interrogating our implanted sensor noninvasively through the skin. Combining a tissue-integ…
Charge State of Silver Halide Colloids Determines the Antibacterial Activity in Amorphous Calcium Phosphate
2013
Removal of bacteria is important not only at implantation, but after long-term implant/prosthesis use. This requires strategies that employ different approaches for combating bacteria. Halides have the potential of an additional mechanism, and together with silver may provide a more powerful antibacterial strategy. Silver iodide was synthesized as colloids with a positive and negative charge and incorporated into an amorphous calcium phosphate (ACP) to provide a possible greater antibacterial action. Colloids were characterized by FTIR spectroscopy and the charge measured by zeta potential. Phase analysis by X-ray diffraction patterns confirmed the formation of b-AgI nanoparticles. Minimum …
Cell and tissue response to nanotextured Ti6Al4V and Zr implants using high-speed femtosecond laser-induced periodic surface structures
2019
In this paper, the effect of femtosecond laser nanotexturing of surfaces of Ti6Al4V and Zr implants on their biological compatibility is presented and discussed. Highly regular and homogeneous nanostructures with sub-micrometer period were imprinted on implant surfaces. Surfaces were morphologically and chemically investigated by SEM and XPS. HDFa cell lines were used for toxicity and cell viability tests, and subcutaneous implantation was applied to characterize tissue response. HDFa proliferation and in vivo experiments evidenced the strong influence of the surface topography compared to the effect of the surface elemental composition (metal or alloy). The effect of protein adsorption fro…
Nonthrombogenic, Biodegradable Elastomeric Polyurethanes with Variable Sulfobetaine Content
2014
For applications where degradable polymers are likely to have extended blood contact, it is often important for these materials to exhibit high levels of thromboresistance. This can be achieved with surface modification approaches, but such modifications may be transient with degradation. Alternatively, polymer design can be altered such that the bulk polymer is thromboresistant and this is maintained with degradation. Toward this end a series of biodegradable, elastic polyurethanes (PESBUUs) containing different zwitterionic sulfobetaine (SB) content were synthesized from a polycaprolactone-diol (PCL-diol):SB-diol mixture (100:0, 75:25, 50:50, 25:75 and 0:100) reacted with diisocyanatobuta…