scholarly journals The Effect of Hydroxyapatite Nanocrystals on Osseointegration of Titanium Implants: AnIn VivoRabbit Study

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Karin Breding ◽  
Ryo Jimbo ◽  
Mariko Hayashi ◽  
Ying Xue ◽  
Kamal Mustafa ◽  
...  

Osseointegration is dependent on implant surface characteristics, including surface chemistry and topography. The presence of nanosized calcium phosphates on the implant surface is interesting to investigate since they affect both the nanotopography and surface chemistry, forming a bone mineral resembling surface. In this work, the osseointegration of titanium implants with and without the presence of hydroxyapatite (HA) nanocrystals has been evaluatedin vivo. The integration was examined using removal torque measurements and real-time polymerase chain reaction (RT-PCR) analysis. The study was performed using two healing time points, 3 and 12 weeks. The results showed that the torque needed to remove the implants was insignificant between the non- and HA-coated implants, both at weeks 3 and 12. The RT-PCR, however, showed significant differences for osteoblast, osteoclast, and proinflammation markers when HA nanocrystals were present.

2020 ◽  
Vol 14 (1) ◽  
pp. 52-58 ◽  
Author(s):  
Lee Kian Khoo ◽  
Sirichai Kiattavorncharoen ◽  
Verasak Pairuchvej ◽  
Nisanat Lakkhanachatpan ◽  
Natthamet Wongsirichat ◽  
...  

Introduction: Implant surface modification methods have recently involved laser treatment to achieve the desired implant surface characteristics. Meanwhile, surface modification could potentially introduce foreign elements to the implant surface during the manufacturing process. Objectives: The study aimed to investigate the surface chemistry and topography of commercially available laser-modified titanium implants, together with evaluating the cell morphology and cell adhesion of human fetal osteoblast (hFOB) seeded onto the same implants. Method: Six (6) samples of commercially available laser-modified titanium implants were investigated. These implants were manufactured by two different companies. Three (3) implants were made from commercially pure grade 4 Titanium (Brand X); and three were made from grade 5 Ti6Al4V (Brand Y). The surface topography of these implants was analyzed by scanning electron microscope (SEM) and the surface chemistry was evaluated with electron dispersive x-ray spectroscopy(EDS). Human fetal osteoblasts were seeded onto the implant fixtures to investigate the biocompatibility and adhesion. Results & Discussion: Brand X displayed dark areas under SEM while it was rarely found on brand Y. These dark areas were consistent with their organic matter. The hFOB cell experiments revealed cell adhesion with filopodia on Brand X samples which is consistent with cell maturation. The cells on Brand Y were morphologically round and lacked projections, one sample was devoid of any noticeable cells under SEM. Cell adhesion was observed early at 48 hrs in laser-irradiated titanium fixtures from both the brands. Conclusion: The presence of organic impurities in Brand X should not be overlooked because disruption of the osseointegration process may occur due to the rejection of the biomaterial in an in-vivo model. Nevertheless, there was insufficient evidence to link implant failure directly with carbon contaminated implant surfaces. Further studies to determine the toxicity of Vanadium from Ti6Al4V in an in-vivo environment should indicate the reason for different cell maturation.


2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Liviu Feller ◽  
Yusuf Jadwat ◽  
Razia A. G. Khammissa ◽  
Robin Meyerov ◽  
Israel Schechter ◽  
...  

The properties of biomaterials, including their surface microstructural topography and their surface chemistry or surface energy/wettability, affect cellular responses such as cell adhesion, proliferation, and migration. The nanotopography of moderately rough implant surfaces enhances the production of biological mediators in the peri-implant microenvironment with consequent recruitment of differentiating osteogenic cells to the implant surface and stimulates osteogenic maturation. Implant surfaces with moderately rough topography and with high surface energy promote osteogenesis, increase the ratio of bone-to-implant contact, and increase the bonding strength of the bone to the implant at the interface. Certain features of implant surface chemistry are also important in enhancing peri-implant bone wound healing. It is the purpose of this paper to review some of the more important features of titanium implant surfaces which have an impact on osseointegration.


Author(s):  
Yuhao Zhu ◽  
Antian Xu ◽  
Chuan Zhou ◽  
Yefeng Wu ◽  
Guofen Lin ◽  
...  

Storage in aqueous solution or ultraviolet (UV) irradiation  can  re t ain or regain the hydrophilicity of titanium implant surface.  In this study, t hree types of commercial titanium implants were used : ZBL (ZDI Bone  L evel ® ), CEL (C-tech Esthetic Line ® ) , and modSLA (Straumann SLActive ® ). ZBL and CEL implants were treated with UV irradiation for 4 h. Surface characterization of the four groups (ZBL, ZBL-UV, CEL-UV, modSLA)  was  evaluated by scanning electron microscopy and contact angle measurements. The  in vivo bone response  was  evaluated by removal torque (RTQ) tests and histomorphometric analysis  at  3, 6 , and 12 weeks post-implantation. A total of 144 implants and 36 rabbits were used for experiments according to a previously established randomization sequence. The  ZBL-UV, CEL-UV , andmodSLA groups were hydrophilic, and nanostructures were observed on  the  modSLA implant surface.ModSLA achieved better  RTQ value than ZBL at 12 weeks ( p <0.05). For histomorphometric analysis, ZBL-UV and CEL-UV implants showed higher bone area values in  the  cancellous bone zone at 6 weeks than  did  modSLA and ZBL  implants  ( p <0.05).In  the  cortical bone zone, all groups showed comparable bone-to-implant contact at all healing time points ( p >0.05).Both storage in saline  and UV irradiation could retain or provoke hydr o philic surfaces and improve osseointegration. Compared to storage in saline, UV irradiation displayed slight advantages in promoting new bone formation in cancellous bone zone at  an  early stage.


2020 ◽  
Vol 61 (6) ◽  
pp. 177-187
Author(s):  
Till Kämmerer ◽  
Tony Lesmeister ◽  
Victor Palarie ◽  
Eik Schiegnitz ◽  
Andrea Schröter ◽  
...  

Introduction: We aimed to compare implant osseointegration with calcium phosphate (CaP) surfaces and rough subtractive-treated sandblasted/acid etched surfaces (SA) in an in vivo minipig mandible model. Materials and Methods: A total of 36 cylindrical press-fit implants with two different surfaces (CaP, n = 18; SA, n = 18) were inserted bilaterally into the mandible of 9 adult female minipigs. After 2, 4, and 8 weeks, we analyzed the cortical bone-to-implant contact (cBIC; %) and area coverage of bone-to-implant contact within representative bone chambers (aBIC; %). Results: After 2 weeks, CaP implants showed no significant increase in cBIC and aBIC compared to SA (cBIC: mean 38 ± 5 vs. 16 ± 11%; aBIC: mean 21 ± 1 vs. 6 ± 9%). Two CaP implants failed to achieve osseointegration. After 4 weeks, no statistical difference between CaP and SA was seen for cBIC (mean 54 ± 15 vs. 43 ± 16%) and aBIC (mean 43 ± 28 vs. 32 ± 6). However, we excluded two implants in each group due to failure of osseointegration. After 8 weeks, we observed no significant intergroup differences (cBIC: 18 ± 9 vs. 18 ± 20%; aBIC: 13 ± 8 vs. 16 ± 9%). Again, three CaP implants and two SA implants had to be excluded due to failure of osseointegration. Conclusion: Due to multiple implant losses, we cannot recommend the oral mandibular minipig in vivo model for future endosseous implant research. Considering the higher rate of osseointegration failure, CaP coatings may provide an alternative to common subtractive implant surface modifications in the early phase post-insertion.


Author(s):  
Anders Palmquist ◽  
Omar M. Omar ◽  
Marco Esposito ◽  
Jukka Lausmaa ◽  
Peter Thomsen

Bone-anchored titanium implants have revolutionized oral healthcare. Surface properties of oral titanium implants play decisive roles for molecular interactions, cellular response and bone regeneration. Nevertheless, the role of specific surface properties, such as chemical and phase composition and nanoscale features, for the biological in vivo performance remains to be established. Partly, this is due to limited transfer of state-of-the-art preparation techniques to complex three-dimensional geometries, analytical tools and access to minute, intact interfacial layers. As judged by the available results of a few randomized clinical trials, there is no evidence that any particular type of oral implant has superior long-term success. Important insights into the recruitment of mesenchymal stem cells, cell–cell communication at the interface and high-resolution imaging of the interface between the surface oxide and the biological host are prerequisites for the understanding of the mechanisms of osseointegration. Strategies for development of the next generation of material surface modifications for compromised tissue are likely to include time and functionally programmed properties, pharmacological modulation and incorporation of cellular components.


2007 ◽  
Vol 361-363 ◽  
pp. 749-752
Author(s):  
J. Strnad ◽  
Jan Macháček ◽  
Z. Strnad ◽  
C. Povýšil ◽  
Marie Strnadová

This study was carried out to assess the bone response to alkali-modified titanium implant surface (Bio surface), using histomorphometric investigation on an animal model. The mean net contribution of the Bio surface to the increase in bone implant contact (BIC) with reference to the turned, machined surface was evaluated at 7.94 % (BIC/week), within the first five weeks of healing. The contribution was expressed as the difference in the osseointegration rates ( BIC/'healing time) between the implants with alkali modified surface (Bio surface) and those with turned, machined surface. The surface characteristics that differed between the implant surfaces, i.e. surface morphology, specific surface area, contact angle, hydroxylation/hydration, may represent factors that influence the rate of osseointegration.


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 4739-4739
Author(s):  
Cristina Castilla-LLorente ◽  
Mineo Iwata ◽  
Marco Mielcarek ◽  
V. Kraig Abrams ◽  
Billanna Hwang ◽  
...  

Abstract Mesenchymal stromal cells (MSCs) expanded ex vivo from aspirated marrow, have been used clinically with variable success to facilitate repair of infarcted hearts, treat graft versus host disease, and facilitate marrow reconstitution after radiation damage. While it is now generally acknowledged that these benefits are not the result of engraftment and differentiation of MSC into the target tissues, the mechanism by which these beneficial effects are achieved is not clear. We hypothesize that MSCs mediate their effect by activating an endogenous cell population which in turn modulates the immune response and/or homes to damaged tissue and participates in repair. To begin to test this hypothesis immortalized and cloned populations of canine MSC were generated to provide a consistent product for in vivo testing. One line, designated DS-1, has been evaluated in vivo by infusion into two normal dogs. Blood samples were taken pre infusion, immediately following infusion and at 1, 6, 24, 48, 72, 96 hours, and 7, 14, 21, and 28 days post infusion. Following infusion there was no consistent change in the number of WBC, however by day 3 there was a marked decrease in the % of CD3+ cells expressing FOXP3 and TGFβ in the blood, which did not recover to pre-infusion levels during the period of observation. At autopsy there was an increased number of these cells in the lymph nodes and spleen, whereas there was an overall decrease in the number of TH1 cells in these tissues. Quantitative RT- PCR analysis of cDNA prepared from blood mononuclear cells indicated an upregulation in the expression of CD133, Tie-2, and MARCO between 1–24 hours post infusion, and an increase in LOX1/OLR1 between 2–4 days. However the % of monocytes and the expression levels of CD14, CD68, CD45, and CD105/Endoglin were constant at all time points. Samples taken at 6 hours, 4 and 7 days post infusion were also analyzed for the presence of DS-1 cells by PCR and in vitro out growth assays. Results indicated that the DS-1cells were detectable up to 6 hours post infusion, but not thereafter. Adherent cells grown from blood mononuclear cells at days 4 and 7, displayed macrophage and endothelial cell morphologies. RT-PCR analysis of these cultures detected expression of macrophage associated markers CD14+/CD68+/MARCO+/LOX1+, as well as endothelial cell associated markers CD34+/CD144/VECAD+. These data indicate that a single infusion of DS-1 cells results in activation of circulating monocytes and a shift of regulatory T cells from the periphery to lymph nodes and spleen which persists for at least 28 days. We speculate that these changes may contribute to the immunomodulatory effects reported for some preparations of MSC.


Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 2389-2389
Author(s):  
Lev Silberstein ◽  
Masatake Osawa ◽  
Charles Lin ◽  
Peter Kharchenko ◽  
Cristina Lo Celso ◽  
...  

Abstract Abstract 2389 Osteolineage cells (OLCs) have been shown to participate in a regulatory bone marrow microenvironment for the hematopoietic stem and progenitor cells (HSPCs) – the endosteal niche. Our previous experiments using live animal imaging have demonstrated that single transplanted HSPCs preferentially home in close proximity to the individual OLCs. We hypothesized that these HSPC-proximal cells represent a distinct subpopulation of OLCs, which is specifically involved in a non-cell autonomous regulation of HSPC quiescence and self-renewal. To test this hypothesis, we developed a novel experimental platform, which allows visualization of HSPC-OLC cell pairs in-vivo and retrieval of the individual OLCs for molecular analysis. We intravenously injected DiI labeled adult bone marrow-derived FACS-sorted Lin−Sca1+c-kit+CD34−Flk2− HSPCs into irradiated newborn collagen 2.3GFP mouse recipients; in this transgenic strain, the majority of the OLCs are labeled with green fluorescent protein (GFP). 48 hours later, we sacrificed the animals and obtained fresh unfixed sections of femoral trabecular bone. Using a combination of differential interference contrast fluorescent microscopy, in-situ enzymatic digestion and micromanipulation, we harvested individual GFP-positive OLCs located within 2 cell diameters (“niche” OLCs) or greater than 5 cell diameters (“control” OLCs) from single DiI-bright HSPCs. Following reverse transcription and cDNA amplification with 29 cycles of PCR, as per the single cell RNA-Seq protocol (Tang et al, Nature Protocols 2010), we performed real-time RT-PCR analysis of 31 samples – 15 niche cells and 16 controls - for the OLC signature genes (osteocalcin, osterix) and for the genes implicated in playing a functional role in the HSPC-OLC cell interaction (osteopontin, CXCL12, angiopoietin 1). Transcripts for GAPDH, collagen 1 and GFP served as positive controls for the amplification. As expected, all cells were positive for GFP and over 85% cells expressed collagen 1. Osteopontin and CXCL12 were expressed at a similar level and frequency in the niche and control OLCs. However, we found that angiopoietin 1 transcripts were detected exclusively in the niche OLCs (3/15 versus 0/16, p <0.05 by Chi-squared). Moreover, niche OLCs were enriched for the osterix-positive cells (7/15 versus 2/16, p <0.05 by Chi-squared) and expressed a lower level of osteocalcin, as normalized for GAPDH expression (1.13 vs. 0.97, p< 0.05 by t-test). Our results suggest that niche OLCs may have a distinct molecular signature and reside within a population of very immature OLCs, as evidenced by the osterix + osteocalcin low phenotype. Further unbiased transcriptome characterization of these cells using genome-wide RNA-Seq assay is therefore likely to provide more evidence in support of our hypothesis and reveal novel non-cell autonomous regulators of HSPC quiescence. To our knowledge, this approach represents the first attempt to define molecular heterogeneity in-vivo at a single cell level using the micro-anatomical relationship between two heterologous cell types. Disclosures: Scadden: Fate Therapeutics: Equity Ownership.


2007 ◽  
Vol 33 (2) ◽  
pp. 89-95 ◽  
Author(s):  
Giovanna Iezzi ◽  
Elisabetta Fiera ◽  
Antonio Scarano ◽  
Gabriele Pecora ◽  
Adriano Piattelli

Abstract Little is known about the in vivo healing processes at the interface of implants placed in different grafting materials. For optimal sinus augmentation, a bone graft substitute that can regenerate high-quality bone and enable the osseointegration of load-bearing titanium implants is needed in clinical practice. Calcium sulphate (CaS) is one of the oldest biomaterials used in medicine, but few studies have addressed its use as a sinus augmentation material in conjunction with simultaneous implant placement. The aim of the present study was to histologically evaluate an immediately loaded provisional implant retrieved 7 months after simultaneous placement in a human sinus grafted with CaS. During retrieval bone detached partially from one of the implants which precluded its use for histologic analysis. The second implant was completely surrounded by native and newly formed bone, and it underwent histologic evaluation. Lamellar bone, with small osteocyte lacunae, was present and in contact with the implant surface. No gaps, epithelial cells, or connective tissues were present at the bone–implant interface. No residual CaS was present. Bone–implant contact percentage was 55% ± 8%. Of this percentage, 40% was represented by native bone and 15% by newly formed bone. CaS showed complete resorption and new bone formation in the maxillary sinus; this bone was found to be in close contact with the implant surface after immediate loading.


2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Fu-Yuan Teng ◽  
Wen-Cheng Chen ◽  
Yin-Lai Wang ◽  
Chun-Cheng Hung ◽  
Chun-Chieh Tseng

This study designed a biomimetic implant for reducing healing time and achieving early osseointegration to create an active surface. Bone morphogenetic protein-2 (BMP-2) is a strong regulator protein in osteogenic pathways. Due to hardly maintaining BMP-2 biological function and specificity, BMP-2 efficient delivery on implant surfaces is the main challenge for the clinic application. In this study, a novel method for synthesizing functionalized silane film for superior modification with BMP-2 on titanium surfaces is proposed. Three groups were compared with and without BMP-2 on modified titanium surfaces in vitro and in vivo: mechanical grinding; electrochemical modification through potentiostatic anodization (ECH); and sandblasting, alkali heating, and etching (SMART). Cell tests indicated that the ECH and SMART groups with BMP-2 markedly promoted D1 cell activity and differentiation compared with the groups without BMP-2. Moreover, the SMART group with a BMP-2 surface markedly promoted early alkaline phosphatase expression in the D1 cells compared with the other surface groups. Compared with these groups in vivo, SMART silaning with BMP-2 showed superior bone quality and created contact areas between implant and surrounding bones. The SMART group with BMP-2 could promote cell mineralization in vitro and osseointegration in vivo, indicating potential clinical use.


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