Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:A7KAX9 (grit)
 1,275 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Surface topography plays a critical role in the interaction of dental implants with adjacent tissues. No statistical differences in oxide composition and surface contamination were observed between 600 grit and polished titanium surfaces. The expression of osteoblast phenotype was enhanced when osteoblast progenitor cells (2T9) were stimulated with bone morphogenetic protein-2 on polished and 600 grit titanium surfaces. Bone morphogenetic protein-2 stimulated phenotypic expression on 600 grit titanium surfaces was marked by prolonged alkaline phosphatase specific activity and more rapid osteocalcin production as compared with the polished titanium surfaces. Because the surface area of the 600 grit titanium surface was shown to be 8 percent greater than that of the polished titanium surface, it is possible that increased surface area played a role in the enhanced expression of the osteoblast phenotype.
 ...
PMID:Surface roughness of titanium on bone morphogenetic protein-2 treated osteoblast cells in vitro. 920 1

The goal of this study was to investigate the effect of bone cell response to titanium (Ti) surfaces in the presence of bone morphogenetic protein (BMP)-atelopeptide type I collagen mixture. The atelopeptide type I collagen was used as a potential carrier for the BMP. Sterilized 600-grit Ti samples were used as substrates for the cell culture study. X-ray photoelectron spectroscopy indicated the presence of TiO2 on the Ti surface. The in vitro cell culture study was performed using an osteoblast progenitor cell line derived from mice (2T9). At confluency, the cells cultured on Ti surfaces were divided into three groups: unstimulated culture, culture stimulated by BMP-atelopeptide type I collagen (40 ng/mL), and culture stimulated by atelopeptide type I collagen (40 ng/mL). The unstimulated and atelopeptide type I collagen cultures were controls in this study. After 4 days of incubation, protein production, alkaline phosphatase (ALP) activity, and hexosaminidase activity were observed to be the highest for cells exposed to the BMP-atelopeptide type I collagen mixture. Statistical differences in cellular protein production and ALP activity were observed between the controls and the surfaces exposed to the BMP-atelopeptide type I collagen mixture. Similarly, a statistical difference in hexosaminidase activity was observed between unstimulated Ti surfaces and surfaces exposed to BMP-atelopeptide type I collagen mixture. However, no statistical differences in protein production, ALP activity, and hexosaminidase activity were observed between cells exposed to atelopeptide type I collagen solution and the unstimulated surfaces.
 ...
PMID:Osteoblast progenitor cell responses to characterized titanium surfaces in the presence of bone morphogenetic protein-atelopeptide type I collagen in vitro. 1055 Nov 43

Osteoblast phenotypic expression in monolayer culture depends on surface microtopography. Here we tested the hypothesis that mineralized bone nodule formation in response to osteotropic agents such as bone morphogenetic protein-2 (BMP-2) and dexamethasone is also influenced by surface microtopography. Fetal rat calvarial (FRC) cells were cultured on Ti implant materials (PT [pretreated], Ra = 0.6 microm; SLA [course grit blasted and acid etched], Ra = 4.0 microm; TPS [Ti plasma sprayed], Ra = 5.2 microm) in the presence of either BMP-2 (20 ng/ml) or 10(-8) M dexamethasone (Dex). At 14 days post-confluence, a homogenous layer of cells covered the surfaces, and stacks of cells that appeared to be nodules emerging from the culture surface were present in some areas on all three Ti surfaces. Cell proliferation decreased while alkaline phosphatase specific activity (ALPase) and nodule number generally increased with increasing surface roughness in both control and treated cultures. There was no difference in cell number between the control and Dex-treated cultures for a particular surface, but BMP-2 significantly reduced cell number compared with control or Dex-treated cultures. Treatment with Dex or BMP-2 further increased ALPase on all surfaces except for PT cultures with Dex. Dex had no effect on nodule area in cultures grown on PT or SLA disks, yet increased nodule number by more than 100% in cultures on PT disks. Though the effect of BMP-2 on nodule number was the same as Dex, BMP-2 increased nodule area on all surfaces except TPS, where area was decreased. Ca and P content of the cell layers in control cultures did not vary with surface roughness. However, cultures treated with Dex had increased Ca content on all surfaces, but the greatest increase was seen on SLA and TPS. BMP-2 increased Ca content in cultures on all surfaces, with the greatest increase on the PT surface. BMP-2 treatment increased P content on all surfaces, whereas Dex only increased P on rough surfaces. Of all cultures examined, the Ca/P weight ratio was 2:1 only on rough surfaces with BMP-2, indicating the presence of bone-like apatite. This was further validated by Fourier transform infrared (FTIR) imaging showing a close association between mineral and matrix on TPS and SLA surfaces with BMP-2-treated cells, and individual spectra indicated the presence of an apatitic mineral phase comparable to bone. In contrast, mineral on the smooth surface of BMP-2-treated cultures and on all surfaces where cultures were treated with Dex was not associated with the matrix and the spectra, not typical of bone apatite, implying dystrophic mineralization. This demonstrates that interactions between growth factor or hormone and surface microtopography can modulate bone cell differentiation and mineralization.
 ...
PMID:Osteoblast-mediated mineral deposition in culture is dependent on surface microtopography. 1223 75

During the process of bone formation, titanium (Ti) surface is an important factor in the modulation of osteoblastic function. This study was conducted in order to determine the effects of different Ti surfaces on the biological responses of a human osteoblast-like cell line (MG63). MG63 cells were cultured on smooth (S), sandblasted large-grit and acid etching (SLA), hydroxyapatite (HA), hydroxyfluoride (HF), titanium nitrate (TIN), and diamond-like carbon (DLC) Ti. The morphology of these cells were assessed by SEM. The cDNAs prepared from the total RNAs of the MG63 were hybridized into a human cDNA microarray (1152 elements). The appearances of the surfaces observed by SEM were different on each of the six dental substrate types. The SLA and HA surfaces were determined to be rougher than the others. MG63 cells cultured on SLA and HA exhibited cell-matrix interactions. In the expression of genes involved in osseointegration, several genes, including bone morphogenetic protein, cadherin, integrin, and insulin-like growth factors, were upregulated on the different surfaces. Several genes, including fibroblast growth factor receptor 4, Bcl 2-related protein, and collagen, were downregulated on the different surfaces. The attachment and expression of key osteogenic regulatory genes were enhanced by the surface roughness of the dental materials used.
 ...
PMID:Effect of various implant coatings on biological responses in MG63 using cDNA microarray. 1662 96

TiO2 nanotube arrays on the surface of dental implants were fabricated by two-step anodic oxidation. Their effects on bone-implant contact were researched by a pilot in vivo study. The implants were classified into four groups. An implant group with TiO2 nanotube arrays and recombinant human bone morphogenetic protein-2 (rhBMP-2) was compared with various surface implants, including machined surface, sandblasted large-grit and acid-etched surface, and TiO2 nanotube array surface groups. The diameter of the TiO2 nanotube window and TiO2 nanotube were ~70 nm and ~110 nm, respectively. The rhBMP-2 was loaded into TiO2 nanotube arrays and elution was detected by an interferometric biosensing method. A change in optical thickness of ~75 nm was measured by flow cell testing for 9 days, indicating elution of rhBMP-2 from the TiO2 nanotube arrays. For the in vivo study, the four groups of implants were placed into the proximal tibia of New Zealand White rabbits. In the implant group with TiO2 nanotube arrays and rhBMP-2, the bone-to-implant contact ratio was 29.5% and the bone volume ratio was 77.3%. Bone remodeling was observed not only in the periosteum but also in the interface between the bone and implant threads. These values were higher than in the machined surface, sandblasted large-grit and acid-etched surface, and TiO2 nanotube array surface groups. Our results suggest that TiO2 nanotube arrays could potentially be used as a reservoir for rhBMP-2 to reinforce osseointegration on the surface of dental implants.
...
PMID:Improved osseointegration of dental titanium implants by TiO2 nanotube arrays with recombinant human bone morphogenetic protein-2: a pilot in vivo study. 2570 38

In order to explore the abilities of an integrated three-dimensional micro-nano topography in immunomodulation and promoting bone formation, present study focuses on the titanium sheets used in the micro-nano topography by treating them with the sandblasted, large-grit and acid-etched (SLA)and alkaline thermal reaction. Further, we characterized and obtained the surface morphology, roughness, and hydrophilicity of the titanium sheets. Moreover, we detected their in vitro cytocompatibility and cell proliferation as well. In addition, investigation was carried out for the immunomodulatory ability of the titanium sheets in a micro-nano topography by observing the expression of M1 (classical activated macrophage) and M2 (alternatively activated macrophage) type marker factors, inflammatory factors, and morphological changes of RAW264.7 cells cultured on the titanium sheets in different topographies. Through cell migration experiments and coculture, we observed the effects of different titanium sheet immune environments on osteoblast migration, extracellular matrix mineralization, and osteoblast gene expression. These results showed that the micro-nano topography constructed through SLA and alkaline thermal treatment improved the hydrophilicity and promoted the cell proliferation. Moreover, it promoted RAW264.7 cells to polarize as M2 phenotype, thereby leading to the anti-inflammatory effect of local microenvironments. This facilitated osteoblasts to secrete bone morphogenetic protein-2 (BMP2) and vascular endothelial growth factor. Nonetheless, these findings provided a theoretical basis for the molecular biological mechanism related to implants in a micro-nano topography which promoted the osteointegration while offering a meaningful theoretical basis for the clinical treatment of such implants.
 ...
PMID:Effect of the immune responses induced by implants in a integrated three-dimensional micro-nano topography on osseointegration. 3325 67