Biokinetics and tissue response to ultrananocrystalline diamond nanoparticles employed as coating for biomedical devices

Abstract

Although Ultrananocrystalline diamond (UNCD) has been proposed as a coating material for titanium biomedical implants, the biological effects and toxicity of UNCD particles that could eventually detach have not been studied to date. The biokinetics and biological effects of UNCD compared to titanium dioxide (TiO ) nanoparticles was evaluated in vivo using Wistar rats (n = 30) i.p. injected with TiO , UNCD or saline solution. After 6 months, blood, lung, liver, and kidney samples were histologically analyzed. Oxidative damage by membrane lipidperoxidation (thiobarbituric acid reactive substances-TBARS), generation of reactive oxygen species (superoxide anion- O2-), and antioxidant enzymes (superoxide dismutase-SOD, catalase-CAT) was evaluated in lung and liver. Histologic observation showed agglomerates of TiO or UNCD in the parenchyma of the studied organs, though there were fewer UNCD than TiO deposits. In addition, TiO caused areas compatibles with foci of necrosis in the liver and renal hyaline cylinders. Regarding UNCD, no membrane damage (TBARS) or mobilization of enzymatic antioxidants was observed either in lung or liver samples. No variations in O2- generation were observed in lung (Co: 35.1 ± 4.02 vs. UNCD: 48 ± 9.1, p > 0.05). Conversely, TiO exposure caused production of O2- in alveolar macrophages and consumption of catalase (p < 0.05). The studied parameters suggest that UNCD caused neither biochemical nor histological alterations, and therefore may prove useful as a surface coating for biomedical implants. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 2408-2415, 2017.

Peri‐implantitis is not periodontitis: Scientific discoveries shed light on microbiome‐biomaterial interactions that may determine disease phenotype

“…26,27 A study using 16S RNA sequencing to analyze adjacent peri-implant and periodontal microbiomes in states of health and disease found that 85% of individuals shared less than 8% of abundant species between teeth and implants. 28 Furthermore, peri-implant communities demonstrated less diversity than periodontal microbial communities. 28 The important observation of a distinct microbial signature in peri-implantitis compared with periodontitis [28][29][30] necessitates research on the capability of the host to mount or potentially resolve an inflammatory response against peri-implant bacteria.…”

“…28 Furthermore, peri-implant communities demonstrated less diversity than periodontal microbial communities. 28 The important observation of a distinct microbial signature in peri-implantitis compared with periodontitis [28][29][30] necessitates research on the capability of the host to mount or potentially resolve an inflammatory response against peri-implant bacteria. While it is likely that the oral taxa that colonize implant biomaterial surfaces originate from dental biofilms, crevicular and extra-crevicular reservoirs.…”

“…33 When corrosion processes occur in combination with tribological processes, the resulting effect is known as tribocorrosion; and when tribocorrosion takes place in a biological system it is termed biotribocorrosion. 28,[33][34][35] While it was previously speculated that, after mechanical or electrochemical attacks, biomedical titanium implants can readily be repassivated by a layer of titanium dioxide on their surface, thus preventing further corrosion and dissolution, a new electrochemical peri-implant inflammation model has provided further insights into the behaviors of titanium implants in biological systems. Berbel et al 5 exposed titanium implant surfaces to peri-implant inflammatory conditions and showed, for the first time, that the limited access to oxygen in the peri-implant defect environment limits the ability of the titanium implant surface to be repassivated over time and accordingly reduces the resistance of implants to corrosion.…”

“…As previously discussed, contemporary culture‐free methods for microbial identification have unveiled dissimilarities between the subgingival microbiome around teeth and implants that could provide an answer to the aforementioned distinct disease phenotypes 26,27 . A study using 16S RNA sequencing to analyze adjacent peri‐implant and periodontal microbiomes in states of health and disease found that 85% of individuals shared less than 8% of abundant species between teeth and implants 28 . Furthermore, peri‐implant communities demonstrated less diversity than periodontal microbial communities 28 .…”

Diamond thin films: giving biomedical applications a new shine

“…TiO 2 particles induced necrosis and cell membrane damage accompanied by generation of reactive oxygen species both in lung and liver tissue. Conversely, none of these effects were observed in the case of UNCD nanoparticles [ 79 ].…”