Effect of porous titanium coating thickness on in vitro osteoblast phenotype expression (original) (raw)
Related papers
Osteoblast response to porous titanium and biomimetic surface: In vitro analysis
Materials Science and Engineering: C, 2015
This study analyzed the behavior of human osteoblasts cultured on porous titanium specimens, with and without biomimetic treatment, compared to dense titanium. Design: The experiment had seven groups: Group 1: cells cultured on polystyrene of culture plate wells; Group 2: cells cultured on dense titanium specimen; Group 3: specimen with 33.79% of pores; Group 4: 41.79% of pores; Groups 5, 6 and 7: specimens similar to groups 2, 3 and 4, yet with biomimetic treatment. Real time-polymerase chain reaction with reverse transcription of the following genes was performed: prostaglandin E2 synthase, integrin β1, osterix, Runx2, Interleukin 6, macrophage colony stimulating factor, apolipoprotein E and others. The study achieved data on cell adhesion, growth and viability, total protein content, alkaline phosphatase activity and quantity of mineralized nodule formations. Data were statistically evaluated. Results: Adherent cells and alkaline phosphatase activity were similar in titanium specimens, regardless of the groups. Biomimetic treatment reduced the total protein activity and the viability of tested cells. Most tested genes had statistically similar expression in all groups. Conclusion: The tested porosities did not cause alterations in osteoblast behavior and the biomimetic treatment impaired the biocompatibility of titanium causing cytotoxicity.
Porous Titanium Associated with CaP Coating: In Vivo and In Vitro Osteogenic Performance
Materials Research, 2017
This in vitro and in vivo study compared different topographies of Ti samples (dense, porosity of 30% and 40%) with or not CaP coating, prepared by powder metallurgy. Osteogenic cells from newborn rat calvaria were plated onto the samples and cell adhesion (24 hours), alkaline phosphatase activity (7 and 10 days) and mineralization nodules (14 days) were assessed. Sixteen rabbits were used for in vivo study. Each animal received three non-treated and three treated implants in the right or left tibia, respectively. Histometric evaluation of bone-implant contact (BIC) were assessed at 1, 2, 4 and 8 weeks. Metallographic analysis revealed porosities of 30% and 40%, with pore size ranging from 250 to 350 µm. Cell adhesion test and ALP revealed similar cell behavior, independently of topography and CaP coating (P > 0.05%). However, CaP coating combined with porosity of 40% influenced positively the mineralized matrix formation (P < 0.05%). CaP-coated implants showed higher BIC than non-CaP implants and BIC was different between the short (1 and 2 weeks) and long (4 and 8 weeks) healing periods (P < 0.05%). The results suggest that CaP coating combined with 40% porosity implants allowed greater osteogenesis in vitro and increased BIC in vivo.
Journal of Materials Science: Materials in Medicine, 2015
Tests on titanium alloys that possess low elastic modulus, corrosion resistance and minimal potential toxicity are ongoing. This study aimed to evaluate the behavior of human osteoblastic cells cultured on dense and porous Titanium (Ti) samples comparing to dense and porous Ti-35 Niobium (Ti-35Nb) samples, using gene expression analysis. Scanning electronic microscopy confirmed surface porosity and pore interconnectivity and X-ray diffraction showed titanium beta-phase stabilization in Ti-35Nb alloy. There were no differences in expression of transforming growth factor-b, integrin-b1, alkaline phosphatase, osteopontin, macrophage colony stimulating factor, prostaglandin E synthase, and apolipoprotein E regarding the type of alloy, porosity and experimental period. The experimental period was a significant factor for the markers: bone sialoprotein II and interleukin 6, with expression increasing over time. Porosity diminished Runtrelated transcription factor-2 (Runx-2) expression. Cells adhering to the Ti-35Nb alloy showed statistically similar expression to those adhering to commercially pure Ti grade II, for all the markers tested. In conclusion, the molecular mechanisms of interaction between human osteoblasts and the Ti-35Nb alloy follow the principal routes of osseointegration of commercially pure Ti grade II. Porosity impaired the route of transcription factor Runx-2.
The Effects of Different Titanium Surfaces on the Behaviour of Osteoblast-Like Cells
This study investigated the influence of different titanium surfaces on the differentiation of rat osteoblast-like cells (osteo-1). Osteo-1 cells were cultured on the following titanium surfaces: 1) pretreated, smooth surface (PT); 2) sandblasted and acid etched surface (SLA); and 3) sandblasted and acid-etched surface rinsed under nitrogen protection to prevent exposure to air and preserved in isotonic saline solution (modSLA). Cell metabolism, total protein content, collagen content and alkaline phosphatase (AP) activity and the formation of calcified nodules were analyzed. The titanium surface did not influence cell metabolism, total protein content and collagen content. The SLA surface influenced cell differentiation, with the observation of a significant reduction of AP activity and formation of calcified nodules after 21 days compared to the PT surface. No difference was observed between the PT and modSLA surfaces. All titanium surfaces tested permitted the full expression of the osteoblast phenotype by osteo-1 cells, including matrix mineralization.
Osteoblast response to biomimetically altered titanium surfaces
Acta Biomaterialia, 2008
Bioinert titanium (Ti) materials are generally encapsulated by fibrous tissue after implantation into the living body. To improve the bone-bonding ability of Ti implants, we activated commercially pure titanium (cpTi) by a simple chemical pre-treatment in HCl and NaOH. Subsequently, we exposed the treated samples to simulated body fluid (SBF) for 2 (TiCT) and 14 days (TiHCA), respectively, to mimic the early stages of bone bonding and to investigate the in vitro response of osteoblasts on thus altered biomimetic surfaces. Sample surfaces were characterized by scanning electron microscopy, energy-dispersive X-ray analysis, cross-sectional transmission electron microscopy analyses, Fourier transform infrared and Raman spectroscopy. It was shown that the efflorescence consisting of sodium titanate that is present on pre-treated cpTi surfaces transformed to calcium titanate after 2 days in SBF. After 14 days in SBF a homogeneous biomimetic apatite layer precipitated. Human osteoblasts (MG-63) revealed a well spread morphology on both functionalized Ti surfaces. On TiCT, the gene expression of the differentiation proteins alkaline phosphatase (ALP) and bone sialo protein was increased after 2 days. On both TiCT and TiHCA, the collagen I and ALP expression on the protein level was enhanced at 7 and 14 days. The TiCT and the TiHCA surfaces reveal the tendency to increase the differentiated cell function of MG-63 osteoblasts. Thus, chemical pre-treatment of titanium seems to be a promising method to generate osteoconductive surfaces.
Clinical Oral Implants Research, 2009
The aim of this study was to evaluate the development of the osteoblastic phenotype in human alveolar bone-derived cells grown on collagen type I-coated titanium (Ti) surface (Col-Ti) obtained by plasma deposition acrylic acid grafting compared with machined Ti (M-Ti). Material and methods: Osteoblastic cells were cultured until subconfluence and subcultured on Col-Ti and M-Ti for periods of up to 21 days. Results: Cultures grown on Col-Ti and M-Ti exhibited similar cell morphology. Cell adhesion, total protein content, and alkaline phosphatase (ALP) activity were not affected by Ti surface modification in all evaluated periods. Growth analyses indicated that there were significantly more cells in cultures grown on Col-Ti at day 3. Runt-related transcription factor 2 (Runx2), osteopontin (OPN), and osteoprotegerin (OPG) mRNA expression of cells subcultured on Col-Ti was higher, whereas collagen type I (COL) was lower compared with M-Ti. Ti surface modification neither affected the osteocalcin (OC), ALP and receptor activator of NF-kB ligand (RANKL) mRNA expression nor the calcium content extracted from mineralized matrix. Conclusions: These results demonstrated that Col-Ti favours cell growth during the proliferative phase (day 3) and osteoblastic differentiation, as demonstrated by changes in mRNA expression profile during the matrix mineralization phase (day 14), suggesting that this Ti surface modification may affect the processes of bone healing and remodelling.
Clinical Oral Implants Research, 2008
Purpose: To evaluate the effect of polyphosphoric acid (PPA) pre-treatment of titanium (Ti) on the initial attachment, proliferation, and differentiation of mouse osteoblast-like cells (MC3T3-E1). Materials and methods: Adsorption of PPA to Ti was achieved by immersing Ti disks (15 mm in diameter) into 0, 1, and 10 wt% PPA and 10 wt% orthophosphoric acid (OPA) for 24 h. On each pre-treated Ti disk, 5.0 Â 10 4 MC3T3-E1 cells were seeded, and 1, 3, and 5 h later cell attachment was evaluated. Cell proliferation was also determined 1, 3, and 5 days after cell seed. Cell differentiation was evaluated 5, 10, and 15 days after cell seed using osteoblast marker gene expression. Total RNA was purified from each culture and Type-I collagen, alkaline phosphatase, and osteocalcin mRNA expression levels were measured by real-time reverse transcription polymerase chain reaction. Results: Adsorption of PPA or OPA to Ti significantly accelerated initial cell attachment at every time point (Po0.0001). As with cell attachment, cell proliferation was also accelerated on the PPA-treated Ti disks in a dose-dependent manner at every time point (Po0.0001). However, OPA-treated Ti disks did not enhance the cell proliferation. Regarding osteoblastic differentiation, PPA-treated Ti significantly accelerated the Type-I collagen gene expression at 5 and 10 days after cell seed. Regarding alkaline phosphatase and osteocalcin gene expression, no significant difference was found among the different Ti surface conditions. Conclusion: The accelerated cell behavior following Ti pre-treatment with PPA is a promising new strategy to fabricate bioactive Ti implants.
Biomedicines
Osseointegration of a titanium implant is still an issue in dental/orthopedic implants durable over time. The good integration of these implants is mainly due to their surface and topography. We obtained an innovative titanium surface by shooting different-in-size particles of Al 2 O 3 against the titanium scaffolds which seems to be ideal for bone integration. To corroborate that, we used two different cell lines: MLO-Y4 (murine osteocytes) and 293 (human fibroblasts) and tested the titanium scaffolds untreated and treated (i.e., Al 2 O 3 shot-peened titanium surfaces). Distribution, density, and expression of adhesion molecules (fibronectin and vitronectin) were evaluated under scanning electron microscope (SEM) and confocal microscope (CM). DAPI and fluorochrome-conjugated antibodies were used to highlight nuclei, fibronectin, and vitronectin, under CM; cell distribution was analyzed after gold-palladium sputtering of samples by SEM. The engineered biomaterial surfaces showed under SEM irregular morphology displaying variously-shaped spicules. Both SEM and CM observations showed better outcome in terms of cell adhesion and distribution in treated titanium surfaces with respect to the untreated ones. The results obtained clearly showed that this kind of surface-treated titanium, used to manufacture devices for dental implantology: (i) is very suitable for cell colonization, essential prerequisite for the best osseointegration, and (ii) represents an excellent solution for the development of further engineered implants with the target to obtain recovery of stable dental function over time.