Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.3.1 (alkaline phosphatase)
 47,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The behavior of cultured rat bone cells growing on modified polyethylene terephthalate (mPET), glass, and machinable ceramic substrates containing enstatite (MgO, SiO2) and glass (CaO-P2O5-Al2O3) was studied. Cell attachment was measured directly on the substrates using an image analysis system. Electron microscopy observations and the MTT test revealed that cells are able to spread and proliferate on the material surface, keeping a healthy ultrastructure on all materials tested in the present study. After having colonized the surface of the materials, as shown by immunocytochemistry, the cells synthesize an osteoid-like matrix composed of osteocalcin, type I collagen, and fibronectin fibrils. The titration of alkaline phosphatase activity showed that the cells grown on the ceramic exhibit a greater osteogenic activity than those grown on controls (glass and mPET). This osteogenic activity results in a mineralization of the extracellular matrix in cultures on ceramic or plastic whereas only few calcium phosphate crystallite traces were revealed by Von Kossa staining on glass. Enstatite constitutes, therefore, an environment compatible with in vitro bone cell life.
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PMID:Effects of new machinable ceramic on behavior of rat bone cells cultured in vitro. 973 58

Previous studies have shown different macrophage responses to three compact pellets (with slightly different chemical composition) of gel-derived bioactive glass-ceramics of the CaO-P2O5-SiO2 system. In the present study primary bone marrow cells directed in vitro to form osteoblastic or osteoclastic cells were cultivated on glass slides coated by these three glass-ceramics. Glass slides were used as controls. In osteoblastic cultures alkaline phosphatase activity varied, depending on the type of coatings. Northern analysis showed high mRNA expressions of bone-related proteins on both the glass-ceramics and control glass. Mineralized nodules were not formed on the control glass, but coating glass slides with the glass-ceramics promoted mineralization without any substantial differences between the types of coatings. In osteoclastic cultures, the normal morphology of tartrate resistant acid phosphatase-positive multinucleated cells on standard culture plates was altered on the control glass and the glass-ceramics. The number of these cells differed, depending on the type of coatings, with no particular differences in the arrangement of F-actin by these cells. These analyses demonstrate complete biocompatibility of the glass-ceramic coatings but not the control glass, on which the cells failed to form mineralized nodules. The phenotype expression of the cells appeared to be influenced by microstructure, surface roughness, and the general character of the coatings rather than their surface reactivity.
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PMID:Behavior of bone marrow cells cultured on three different coatings of gel-derived bioactive glass-ceramics at early stages of cell differentiation. 978 7

Fresh marrow cells were obtained from femora of Fischer rats and cultured in a medium containing 15% fetal calf serum (FCS) until confluence. After trypsinization, cells were subcultured at a cell density of 100 x 10(3)/35-mm well in the presence of FCS, beta-glycerophosphate, and ascorbic acid phosphate on four different culture substrata. The period of subculture was 2 weeks; the substrata used were the culture dish, apatite-wollastonite containing glass ceramic (AW), hydroxyapatite coated AW (HA/AW), and Al2O3 doped AW (Al/AW). The HA coating was attained by the incubation of AW in simulated physiological solution. The glass matrix of AW and HA/AW contained MgO, CaO, P2O5, and SiO2; Al/AW contained Al2O3 in addition to these components. The subculture on Al/AW substratum showed many alkaline phosphatase (ALP) positive nodules and the highest ALP activity. On a Northern blot analysis the housekeeping gene of beta-actin mRNA was evenly detected from the cells cultured on all substrata; however, bone-specific osteocalcin mRNA was only detected from the cells on Al/AW. These results indicate that Al/AW provokes the osteoblastic differentiation of marrow stromal stem cells.
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PMID:Al2O3 doped apatite-wollastonite containing glass ceramic provokes osteogenic differentiation of marrow stromal stem cells. 1039 41

A new biocompatible glass, which is composed of CaO, P2O5, SiO2, and Al2O3 (abbreviated CPSA) and is characterized by higher elasticity than previous bioglass products, was molded into fibers with a diameter of 9 microm. With CPSA fibers, two geometrically different structures, balls and bundles (each 20 mg in weight), were prepared, combined with 2.2 microg of rhBMP-2 (a gift from Yamanouchi Co., Japan) and implanted subcutaneously into rats. The histology showed remarkably higher bone formation in the ball-CPSA/BMP at 2 and 4 weeks than in the bundle-CPSA/BMP. The ball-CPSA/BMP showed 10 times higher alkaline phosphatase (ALP) activity at the second week and 5 times higher osteocalcin content at the fourth week than the bundle-CSPA/BMP. Vascular development in the implants was evaluated by mRNA expression of Flt-1 and KDR, two receptors for vascular endothelial growth factor (VEGF). Both receptors showed higher expression in the case of the ball, while they were not detected in the bundle. It is concluded that the BMP-induced bone formation depends highly upon the porous vasculature-inducing geometry of the matrix, which can be constructed with the new CPSA fibers.
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PMID:Geometric effect of matrix upon cell differentiation: BMP-induced osteogenesis using a new bioglass with a feasible structure. 1113 71

The present in vitro study doped hydroxyapatite (HA) with various metal cations (Mg(2+), Zn(2+), La(3+), Y(3+), In(3+), and Bi(3+)) in an attempt to enhance properties of HA pertinent to orthopedic and dental applications. X-ray diffraction material characterization indicated that the metal cations may have substituted for calcium in the HA crystal structure and that all of the doped HA formulations were single-phase and crystalline. Scanning electron microscopy analysis revealed a variety of grain sizes, depending on the dopant utilized. Energy-dispersive spectroscopy confirmed that the dopants added during synthesis were present and that all of the HA formulations synthesized were within the defined range of HA phase in the CaO-P(2)O(5)-H(2)O system. Lastly, Bi-doped HA had a slower dissolution rate than either undoped HA or HA doped with other cations when exposed to simulated physiological conditions for 21 days. In terms of cell function, results provided the first evidence that osteoblasts, bone-forming cells, adhered and differentiated (as measured by alkaline phosphatase synthesis) in response to HA doped with trivalent cations (specifically, La(3+), Y(3+), In(3+), Bi(3+)) at earlier time points than either HA doped with divalent cations (Mg(2+), Zn(2+)) or undoped HA. Of the dopants examined, Bi(3+) most enhanced osteoblast long-term calcium-containing mineral deposition. For these reasons, this study revealed for the first time the potential benefits of doping HA with Bi(3+) according to criteria critical for bone prosthetic clinical success.
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PMID:Osteoblast response to hydroxyapatite doped with divalent and trivalent cations. 1474 26

The purpose of this study was to investigate calcium phosphate glass as a potential biomaterial for hard tissue repair. We prepared calcium phosphate glass using the system CaO-CaF(2)-P(2)O(5)-MgO-ZnO and cultured MC3T3-E1 cells onto the glass in alpha-MEM with beta-glycerophosphatase and ascorbic acid. Proliferation of the cells was determined to evaluate the biocompatibility of the prepared calcium phosphate glass. The alkaline phosphatase activity was measured to examine the osteoblast differentiation. Mineralization was evaluated by staining the calcium precipitates with Alizarin red. Culture onto the calcium phosphate glass exhibited no significant influence on cell proliferation compared to the polystyrene chosen as a control in this experiment (p > 0.05). The alkaline phosphatase activity in the experimental group, however, was enhanced by the calcium phosphate glass significantly at 10-18 days after incubation than that of the control group (p < 0.05). The promotion of bone-like tissue formation by the calcium phosphate glass was observed after 7 days and thereafter. The results of the present study indicate that the prepared calcium phosphate glass affects osteogenesis by increasing calcification of the extracellular matrix.
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PMID:Proliferation, differentiation, and calcification of preosteoblast-like MC3T3-E1 cells cultured onto noncrystalline calcium phosphate glass. 1499 67

Bioactive glass material of the type CaO--P(2)O(5)--SiO(2)--ZnO was obtained by the sol-gel processing method. This material was produced both in powder and in disks form by compression of the powder. The obtained material was characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and surface electron micrograph (SEM). The bioactivity was examined in vitro with respect to the ability of hydroxyapatite layer to form on the surface as a result of contact with simulated body fluid (SBF). The XRD and FTIR studies were conducted before and after contact of the material with SBF. The gel-derived materials were amorphous as shown by XRD, but were able to crystallize calcium phosphates on their surfaces when exposed to SBF. We also examined the alkaline phosphatase (AP) activity of osteoblasts, using human fetal osteoblastic cells (hFOB 1.19) cultured on the zinc bioglass, and compared it with the polystyrene plates. The bone cells consistently expressed higher AP activity in the zinc bioglass materials compared with the polystyrene plates, which indicates the zinc containing composition stimulates bone cells production of AP.
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PMID:Preparation and in vitro bioactivity of zinc containing sol-gel-derived bioglass materials. 1505 94

Using biodegradable bone substitutes in alveolar ridge augmentation avoids second-site surgery for autograft harvesting. Considerable efforts have been undertaken to develop rapidly resorbable bone substitute materials with a higher degree of biodegradability than tricalcium phosphate (TCP). This study examines the effect of novel biodegradable glass ceramics on the expression of bone-related genes and proteins by human bone-derived cells (HBDC) and compares this behavior with that of TCP. Test materials used were alpha-TCP, a surface-treated glass ceramic GB9N with crystalline phase Ca(2)KNa(PO(4))(2) and a small amount of amorphous silica phosphate; AP40 - a glass ceramic based on crystalline phases of apatite and wollastonite; and a glass ceramic Mg5 composed of 20.6% CaO, 58.5% P(2)O(5), 14.4% Na(2)O, 4.1% MgO and 2.4% CaF(2) (wt%). HBDC were grown on the substrata for 3, 5, 7, 14 and 21 days, counted and probed for various bone-related mRNAs and proteins (type I collagen (Col I), osteocalcin (OC), osteopontin (OP), osteonectin (ON), alkaline phosphatase (ALP) and bone sialoprotein (BSP)). The substrata supported continuous cellular growth for 21 days. By day 21, GB9N had the highest number of HBDC. GB9N induced significantly enhanced expression of Col I, ALP, OP, OC and ON mRNA at 3 days; of OP, OC and ON mRNA and protein at 7 and 14 days; and of ALP, OP and OC mRNA and Col I, ALP, BSP, ON and OP protein at 21 days. Since all novel glass ceramics supported cellular proliferation together with expression of bone-related genes and proteins at least as much as TCP, these ceramics can be regarded as potential bone substitutes. GB9N had the most effect on osteoblastic differentiation, thus suggesting that this material may possess a higher potency to enhance osteogenesis than TCP.
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PMID:The effect of bioactive glass ceramics on the expression of bone-related genes and proteins in vitro. 1564 39

Bioactive glasses dissolve upon immersion in culture medium, and release their constitutive ions into solution. There has been some evidence suggesting that these ionic-dissolution products influence osteoblast-specific processes. Here, the effect of 58S sol-gel-derived bioactive glass (60% SiO(2), 36% CaO, 4% P(2)O(5), in molar percentage) on primary osteoblasts derived from human fetal long bone explant cultures is investigated, and it is hypothesized that critical concentrations of sol-gel-dissolution products (consisting of a combination of simple inorganic ions) can enhance osteoblast phenotype in vitro by affecting the expression of a number of genes associated with the differentiation and extracellular matrix deposition processes. Cells were exposed to a range of 58S dosages continuously for a period of 4-14 days in monolayer cultures. Quantitative real-time RT-PCR analysis of a panel of osteoblast-specific markers showed a varied gene expression pattern in response to the material. The highest concentration of Ca and Si tested (96 and 50 ppm, respectively) promoted upregulation of gene expression for most markers (including alkaline phosphatase, osteocalcin, and osteopontin) at the latest time point, compared to non-58S-treated control, although this observation was not statistically significant. The same 58S concentration produced higher ALP activity levels and increased proliferation throughout the culture period, compared to lower dosages tested; however, the results generated were again not statistically significant. The data overall suggest that no significant effect can be ascribed to the ionic products of 58S bioactive gel-glass dissolution tested here and their ability to stimulate osteoblastic marker gene expression.
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PMID:Dose- and time-dependent effect of bioactive gel-glass ionic-dissolution products on human fetal osteoblast-specific gene expression. 1588 38

Two glass ceramics in the CaO--P2O5--MgO system with the incorporation of K2O or TiO2 oxides were prepared with the goal of using them as potential bone graft substitutes. The incorporation of TiO2 and K2O led to the preparation of specific crystalline phases in the structure of the glass ceramics, which show different degrees of biodegradation. In fact, the 45CaO--45P2O5--5MgO--5K2O has been previously demonstrated to be much more soluble in aqueous solutions than the 45CaO--37P2O5--5MgO--13TiO2 glass ceramic. The in vitro biological activity of the two calcium phosphate glass ceramics was studied with the use of human bone marrow osteoblast cell cultures maintained for 28 days, and seeded materials were assessed for cell proliferation and function. The Ti-containing glass ceramic showed a stable surface throughout the culture time, on macroscopic and SEM observation. Osteoblast cells proliferated gradually, especially during the third week, with a high alkaline phosphatase activity and formation of a mineralized matrix. On SEM observation, attached cells appeared with a spread-polygonal morphology typical of the osteoblast cells, with extensive cell-to-cell contact. Cell behavior on the seeded material was similar to that found on cultures performed on tissue-culture-grade polystyrene; except for the presence of lower cell numbers during the first 2 weeks. By contrast, the K-containing glass ceramic showed a highly instable surface with dissolution/precipitation processes occurring throughout the culture time. Few cells adhered to the material surface, and subsequent proliferation was also hindered, especially from the first week onwards. Cell numbers were significantly lower than those observed in the Ti-containing glass ceramic during most of the incubation time. Results suggest that the different in vitro biological behavior of these two glass ceramics is mainly due to the significant differences in the surface degradation rate, which is directly correlated to the chemical composition of the mother glass.
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PMID:In vitro studies of calcium phosphate glass ceramics with different solubility with the use of human bone marrow cells. 1598 37


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