ATP-mediated mineralization of MC3T3-E1 osteoblast cultures

While bone is hypomineralized in hypophosphatemia patients and in tissue-nonspecific alkaline phosphatase (Tnsalp)-deficient mice, the extensive mineralization that nevertheless occurs suggests involvement of other phosphatases in providing phosphate ions for mineral deposition. Although the source of phosphate liberated by these phosphatases is unknown, pyrophosphate, ATP, pyridoxal-5'-phosphate (PLP) and phoshoethanolamine (PEA) are likely candidates. In this study, we have induced mineralization of MC3T3-E1 osteoblast cultures using ATP, and have investigated potential phosphatases involved in this mineralization process. MC3T3-E1 osteoblasts were cultured for 12 days and treated either with beta-glycerophosphate (betaGP) or ATP. Matrix and mineral deposition was examined by biochemical, cytochemical, ultrastructural and X-ray microanalytical methods. ATP added at levels of 4-5 mM resulted in mineral deposition similar to that following conventional treatment with betaGP. Collagen levels were similarly normal in ATP-mineralized cultures and transmission electron microscopy and X-ray microanalysis confirmed hydroxyapatite mineral deposition along the collagen fibrils in the ECM. Phosphate release from 4 mM ATP into the medium was rapid and resulted in approximately twice the phosphate levels than after release from 10 mM betaGP. ATP treatment did not affect mineralization by altering the expression of mineral-regulating genes such as Enpp1, Ank, and Mgp, nor phosphatase genes indicating that ATP induces mineralization by serving as a phosphate source for mineral deposition. Levamisole, an inhibitor of TNSALP, completely blocked mineralization in betaGP-treated cultures, but had minor effects on ATP-mediated mineralization, indicating that other phosphatases such as plasma membrane Ca2+ transport ATPase 1 (PMCA1) and transglutaminase 2 (TG2) are contributing to ATP hydrolysis. To examine their involvement in ATP-mediated mineralization, the inhibitors cystamine (TG2 inhibitor) and ortho-vanadate (PMCA inhibitor) were added to the cultures - both inhibitors significantly reduced mineralization whereas suppression of the phosphate release by ortho-vanadate was minor comparing to other two inhibitors. The contribution of PMCA1 to mineralization may occur through pumping of calcium towards calcification sites and TG2 can likely act as an ATPase in the ECM. Unlike the GTPase activity of TG2, its ATPase function was resistant to calcium, demonstrating the potential for participation in ATP hydrolysis and mineral deposition within the ECM at elevated calcium concentrations.     

Modulation of thrombospondin gene expression during osteoblast differentiation in MC3T3-E1 cells.

The levels of expression of two related extracellular matrix protein genes, thrombospondins 1 and 2 (TSP1 and TSP2), were analyzed in the mouse osteogenic cell line, MC3T3-E1. To monitor differentiation, we also measured two potential markers of the osteoblastic phenotype, alkaline phosphatase (ALP) activity, and alpha 1(I) collagen mRNA levels. TSP1 mRNA levels increased 10- to 15-fold during the first nine days of osteoblastic conversion, and then dropped to a level still significantly above baseline values. This increase in TSP1 mRNA closely paralleled that observed in ALP activity. In contrast, TSP2 mRNA levels were unchanged throughout the 21-day time course. These findings suggest that TSP1 is a marker for osteoblast differentiation and could play a role in the cellular changes that accompany acquisition of the osteoblastic phenotype in MC3T3-E1 cells.     

Relationship between collagen synthesis and expression of the osteoblast phenotype in MC3T3-E1 cells.

The MC3T3-E1 mouse calvaria-derived cell line has been used to study the role of collagen synthesis in osteoblast differentiation. MC3T3-E1 cells, like several previously characterized osteoblast culture systems, expressed osteoblast markers and formed a mineralized extracellular matrix only after exposure to ascorbic acid. Mineralization was stimulated further by beta-glycerol phosphate. Ultrastructural observations indicated that the extracellular matrix produced by ascorbic acid-treated cells was highly organized and contained well-banded collagen fibrils. Expression of osteoblast markers followed a clear temporal sequence. The earliest effects of ascorbic acid were to stimulate type I procollagen mRNA and collagen synthesis (24 h after ascorbate addition), followed by induction of alkaline phosphatase (48-72 h) and osteocalcin (96-144 h) mRNAs. Procollagen mRNA, which was expressed constitutively in the absence of ascorbate, increased only twofold after vitamin C addition. In contrast, alkaline phosphatase and osteocalcin mRNAs were undetectable in untreated cultures. Actions of ascorbic acid on osteoblast marker gene expression are mediated by increases in collagen synthesis and/or accumulation because (1) parallel dose-response relationships were obtained for ascorbic acid stimulation of collagen accumulation and alkaline phosphatase activity, and (2) the specific collagen synthesis inhibitors, 3,4-dehydroproline and cis-4-hydroxyproline, reversibly blocked ascorbic acid-dependent collagen synthesis and osteoblast marker gene expression.     

Polyphosphates inhibit extracellular matrix mineralization in MC3T3-E1 osteoblast cultures

Studies on various compounds of inorganic phosphate, as well as on organic phosphate added by post-translational phosphorylation of proteins, all demonstrate a central role for phosphate in biomineralization processes. Inorganic polyphosphates are chains of orthophosphates linked by phosphoanhydride bonds that can be up to hundreds of orthophosphates in length. The role of polyphosphates in mammalian systems, where they are ubiquitous in cells, tissues and bodily fluids, and are at particularly high levels in osteoblasts, is not well understood. In cell-free systems, polyphosphates inhibit hydroxyapatite nucleation, crystal formation and growth, and solubility. In animal studies, polyphosphate injections inhibit induced ectopic calcification. While recent work has proposed an integrated view of polyphosphate function in bone, little experimental data for bone are available. Here we demonstrate in osteoblast cultures producing an abundant collagenous matrix that normally show robust mineralization, that two polyphosphates (PolyP5 and PolyP65, polyphosphates of 5 and 65 phosphate residues in length) are potent mineralization inhibitors. Twelve-day MC3T3-E1 osteoblast cultures with added ascorbic acid (for collagen matrix assembly) and β-glycerophosphate (a source of phosphate for mineralization) were treated with either PolyP5 or PolyP65. Von Kossa staining and calcium quantification revealed that mineralization was inhibited in a dose-dependent manner by both polyphosphates, with complete mineralization inhibition at 10 μM. Cell proliferation and collagen assembly were unaffected by polyphosphate treatment, indicating that polyphosphate inhibition of mineralization results not from cell and matrix effects but from direct inhibition of mineralization. This was confirmed by showing that PolyP5 and PolyP65 bound to synthetic hydroxyapatite in a concentration-dependent manner. Tissue-nonspecific alkaline phosphatase (TNAP, ALPL) efficiently hydrolyzed the two PolyPs as measured by P_i release. Importantly, at the concentrations of polyphosphates used in this study which inhibited bone cell culture mineralization, the polyphosphates competitively saturated TNAP, thus potentially interfering with its ability to hydrolyze mineralization-inhibiting pyrophosphate (PP_i) and mineralizing-promoting β-glycerophosphate (in cell culture). In the biological setting, polyphosphates may regulate mineralization by shielding the essential inhibitory substrate pyrophosphate from TNAP degradation, and in the same process, delay the release of phosphate from this source. In conclusion, the inhibition of mineralization by polyphosphates is shown to occur via direct binding to apatitic mineral and by mixed inhibition of TNAP.     

Microcarriers facilitate mineralization in MC3T3-E1 cells

Summary MC3T3-E1 cells showed mineral deposits after about 1 week of culture when incubated in the presence of microcarrier beads. These deposits appeared as white spots on the dish surface, and under light microscopy the cells showed multiple cell layers and mineralization around the microcarriers. The deposits stained positive with calcium-specific Von Kossa's method. Using conventional assay, alkaline phosphatase activity (ALP) and parathyroid hormone-stimulated intracellular cAMP production were lower in the microcarrier cultures than in the control, but using cytochemical methods, high alkaline phosphatase activity was found around the microcarriers. These results indicate that microcarriers facilitated the formation of multiple cell layers and provided a culture environment for mineralization.     

Extracellular matrix mineralization in murine MC3T3-E1 osteoblast cultures: An ultrastructural,compositional and comparative analysis with mouse bone

Bone cell culture systems are essential tools for the study of the molecular mechanisms regulating extracellular matrix mineralization. MC3T3-E1 osteoblast cell cultures are the most commonly used in vitro model of bone matrix mineralization. Despite the widespread use of this cell line to study biomineralization, there is as yet no systematic characterization of the mineral phase produced in these cultures. Here we provide a comprehensive, multi-technique biophysical characterization of this cell culture mineral and extracellular matrix, and compare it to mouse bone and synthetic apatite mineral standards, to determine the suitability of MC3T3-E1 cultures for biomineralization studies. Elemental compositional analysis by energy-dispersive X-ray spectroscopy (EDS) showed calcium and phosphorus, and trace amounts of sodium and magnesium, in both biological samples. X-ray diffraction (XRD) on resin-embedded intact cultures demonstrated that similar to 1-month-old mouse bone, apatite crystals grew with preferential orientations along the (100), (101) and (111) mineral planes indicative of guided biogenic growth as opposed to dystrophic calcification. XRD of crystals isolated from the cultures revealed that the mineral phase was poorly crystalline hydroxyapatite with 10 to 20 nm-sized nanocrystallites. Consistent with the XRD observations, electron diffraction patterns indicated that culture mineral had low crystallinity typical of biological apatites. Fourier-transform infrared spectroscopy (FTIR) confirmed apatitic carbonate and phosphate within the biological samples. With all techniques utilized, cell culture mineral and mouse bone mineral were remarkably similar. Scanning (SEM) and transmission (TEM) electron microscopy showed that the cultures had a dense fibrillar collagen matrix with small, 100 nm-sized, collagen fibril-associated mineralization foci which coalesced to form larger mineral aggregates, and where mineralized sites showed the accumulation of the mineral-binding protein osteopontin. Light microscopy, confocal microscopy and three-dimensional reconstructions showed that some cells had dendritic processes and became embedded within the mineral in an osteocyte-like manner. In conclusion, we have documented characteristics of the mineral and matrix phases of MC3T3-E1 osteoblast cultures, and have determined that the structural and compositional properties of the mineral are highly similar to that of mouse bone.     

The effects of low dose X-irradiation on osteoblastic MC3T3-E1 cells in vitro

Background

Recently anti-CCP testing has become popular in the diagnosis of rheumatoid arthritis (RA). However, the inadequate reporting of the relevant diagnostic studies may overestimate and bias the results, directing scientists into making false decisions. The aim of the present study was to evaluate the reporting quality of studies used anti-CCP2 for the diagnosis of RA and to explore the impact of reporting quality on pooled estimates of diagnostic measures.

Methods

PubMed was searched for clinical studies investigated the diagnostic accuracy of anti-CCP. The studies were evaluated for their reporting quality according to STARD statement. The overall reporting quality and the differences between high and low quality studies were explored. The effect of reporting quality on pooled estimates of diagnostic accuracy was also examined.

Results

The overall reporting quality was relatively good but there are some essential methodological aspects of the studies that are seldom reported making the assessment of study validity difficult. Comparing the quality of reporting in high versus low quality articles, significant differences were seen in a relatively large number of methodological items. Overall, the STARD score (high/low) has no effect on the pooled sensitivities and specificities. However, the reporting of specific STARD items (e.g. reporting sufficiently the methods used in calculating the measures of diagnostic accuracy and reporting of demographic and clinical characteristics/features of the study population) has an effect on sensitivity and specificity.

Conclusions

The reporting quality of the diagnostic studies needs further improvement since the study quality may bias the estimates of diagnostic accuracy.     

TNF-alpha and IL-1beta suppress N-cadherin expression in MC3T3-E1 cells.

Excessive production of tumor necrosis factor (TNF) and interleukin-1 (IL-1) secondary to estrogen deficiency have been implicated as the cause of osteoporosis in postmenopausal woman. These cytokines appear to stimulate osteoclast precursor proliferation and activate mature osteoclast formation directly and possibly indirectly via osteoblasts. To investigate the other possible roles that these cytokines may play in stimulating the bone resorption process, we examined the effect of TNF-alpha and IL-1beta on cell-cell adhesion molecules, cadherins, in osteoblastic MC3T3-E1 cells. In this study, we investigated cadherin expression and the effect of TNF-alpha, IL-1beta, and parathyroid hormone (PTH) on the expression of cadherins in MC3T3-E1 cells. Confluent cultures of MC3T3-E1 cells were challenged with recombinant human TNF-alpha (1-100 U/ml), recombinant human IL-1beta (1-100 ng/ml) and human PTH(1-34) (1-100 ng/ml), respectively. The results show that MC3T3-E1 cells express functional cadherin molecules, N-cadherin and OB-cadherin. TNF-alpha (10-100 U/ml) and IL-1beta (10-100 ng/ml) suppressed N-cadherin without changing OB-cadherin expression, while PTH (1-100 ng/ml) had no effect on cadherin expression. These results raise the possibility that TNF-alpha and IL-1beta may compromise the cell-cell adhesion of osteoblasts which cover the bone surface. The ensuing compromised cell-cell adhesion of osteoblasts may in turn facilitate the direct adhesion of osteoclasts on the calcified bone matrix surface. These results implicate an indirect role for osteoblasts in the promotion of bone resorption by TNF-alpha and IL-1beta.     

Lysophosphatidic acid induces chemotaxis in MC3T3-E1 osteoblastic cells

Lysophosphatidic acid (LPA) is a bioactive lipid that has pleiotropic effects on a variety of cell types and enhances the migration of endothelial and cancer cells, but it is not known if this lipid can alter osteoblast motility. We performed transwell migration assays using MC3T3-E1 osteoblastic cells and found LPA to be a potent chemotactic agent. Quantitative time-lapse video analysis of osteoblast migration after wounds were introduced into cell monolayers indicated that LPA stimulated both migration velocity and the average migration distance per cell. LPA also elicited substantial changes in cell shape and actin cytoskeletal structure; lipid-treated cells contained fewer stress fibers and displayed long membrane processes that were enriched in F-actin. Quantitative RT-PCR analysis showed that MC3T3-E1 cells express all four known LPA-specific G-protein-coupled receptors (LPA1-LPA4) with a relative mRNA abundance of LPA1>LPA4>LPA2>LPA3. LPA-induced changes in osteoblast motility and morphology were antagonized by both pertussis toxin and Ki16425, a subtype-specific blocker of LPA1 and LPA3 receptor function. Cell migration in many cell types is linked to changes in intracellular Ca2+. Ki16425 also inhibited LPA-induced Ca2+ signaling in a dose-dependent manner, suggesting a link between LPA-induced Ca2+ transients and osteoblast chemotaxis. Our data show that LPA stimulates MC3T3-E1 osteoblast motility via a mechanism that is linked primarily to the G-protein-coupled receptor LPA1.     

Transforming growth factor-beta reduces the phenotypic expression of osteoblastic MC3T3-E1 cells in monolayer culture

Transforming growth factor beta (TGF-beta) regulates cell growth and differentiation. Since it is abundant in bone, we have studied the effect of the polypeptide upon the growth and phenotypic expression of murine osteoblastic cells in monolayer culture. Its actions were compared to those of epidermal growth factor (EGF), another hormonally active polypeptide known to alter bone cell function. Picogram amounts of TGF-beta were found to inhibit the growth and phenotype (alkaline phosphatase and cAMP response to parathyroid hormone) of the clonal nontransformed MC3T3-E1 osteoblastic cell line. EGF also inhibited phenotypic expression, although at higher (nanogram) concentrations, but stimulated cell growth. The low concentration of TGF-beta required to inhibit growth and phenotype of osteoblastic cells together with its abundance in bone suggest that TGF-beta may be an important regulator of bone cell function.     

Enamel matrix derivative inhibits TNF-alpha-induced apoptosis in osteoblastic MC3T3-E1 cells.

OBJECTIVE: The purpose of this study was to examine the effect of enamel matrix derivative (EMD) on TNF-alpha-induced apoptosis in osteoblastic MC3T3-E1 cells. STUDY DESIGN: MC3T3-E1 cells were cultured at an initial density of 5000/cm 2 in Dulbecco's modified eagle medium (DMEM) with 10% fetal bovine serum (FBS) and allowed to adhere for 24 hours. Medium was then changed into DMEM with 0.5% FBS. After 16 hours, cells were treated with EMD (100 microg/mL) alone, tumor necrosis factor alpha (TNF-alpha) (20 ng/mL) alone, transforming growth factor beta 1 (TGF-beta1) (10 ng/mL) alone, TNF-alpha plus TGF-beta1, or TNF-alpha plus EMD. Cells cultured with DMEM and 0.5% FBS served as control. Following 24-hour incubation, apoptosis was assessed by terminal deoxynucleotidyl transferase nick-end labeling (TUNEL) assay, and quantified by cell death enzyme-linked immunosorbent assay (ELISA). RESULTS: Both TUNEL assay and cell death ELISA show that TNF-alpha induces apoptosis in MC3T3-E1 cells. TNF-alpha increases cell death by approximately 2-fold, which is attenuated by both EMD and TGF-beta1. CONCLUSION: Like TGF-beta1, EMD protects osteoblasts from inflammation-induced apoptosis.     

Action of prostaglandins on clonal osteoblastic MC3T3-E1 cells

Prostaglandins (PG's) are well known as an important local regulator of bone metabolism. In this study, we examined to characterize the effects of PGs on osteoblasts, using a clonal osteoblastic MC3T3-E1 cells. Among PG metabolites, PGE₂ is a main prostanoid released in bone tissues. MC3T3-E1 cells also produced predominantly PGE₂. PG E₂ at low doses (1–100 ng/ml) and PGE₁ increased activity of alkaline phosphatase (ALP), an marker enzyme of early differentiation of osteoblasts, with positive correlation of elevating intracellular cAMP content. The stimulatory effects are amplified by the addition of isobutylmethyl xanthine (IBMX) and mimicked those of forskolin, a direct activator of adenylate cyclase. those results suggest that PGE₂ at low doses and PGE₁ act predominantly on adenylate cyclase to stimulate the early differntiation of the cells. On the other hand, PGE₂ at high doses (500–2000 ng/ml) and PGF_2α stimulated DNA synthesis of the cells in a dose-related manner. In the same range of concentrations, PGE₂ and PGF_2α augmented the accumulation of inositol triphosphates. Further, the effect of these PGs on the DNA synthesis is negated by addition of H-7, a potent inhibitor of protein kinase C. These date suggest that PGE₂ at high doses and PGF_2α stimulate the proliferation of the cells via enhance of phosphatidyl inositol (PI) turnover system and following activation of protein kinase C. Since PGE₂ reveals diverse effects on the cells dependent on its concentration, it is difficult to clarify the mechanism of PGE₂ action. Thus, we chose PGF_2α to elucidate the stimulatory effect of PGs on the prolferation of the cells. At least 12h time-lag was present between PG F_2α-signal transduction and an increase in DNA synthesis, and α-amanitin and cyclohexamide counteracted the effects, suggesting that some proteins involved in DNA synthesis are produced by the addition of PGF_2α in the duration. Further, neutralizing anti IGF-I antibody blocked the stimulation of DNA synthesis by PGF_2α. However, PGF_2α didn't affect the endogenous production of IGF-I of the cells. On the other hand, PGF_2α greatly elevated level of IGF-I binding sites on the cells, and the increase appeared bout 3h earlier than did the stimulation of DNA synthesis, indicating increase in responsiveness of the cells to IGF-I. These results suggest that the proliferation of the cells is stimulated by synergistic action of PGF_2α and IGF-I produced endogenously.     

THSD4基因在小鼠间充质干细胞及MC3T3-E1细胞成骨分化中的作用

目的 探讨THSD4基因对小鼠间充质干细胞和MC3T3-E1细胞成骨分化的影响。方法 提取绝经后骨质疏松症患者的骨髓间充质干细胞进行基因测序分析,与骨关节炎患者的骨髓间充质干细胞进行比较,分析基因表达差异。通过提取不同分化阶段的小鼠骨髓间充质干细胞（M-BMSC）及MC3T3-E1细胞的mRNA来检测THSD4 基因以及成骨分化的标志性基因（ALP、Runx2、Osx）的表达水平。通过构建慢病毒表达载体来实现对M-BMSC及MC3T3-E1细胞中THSD4的敲减及过表达,并观察其对M-BMSC及MC3T3-E1细胞成骨分化能力的影响。结果 THSD4基因在绝经后骨质疏松症患者骨髓间充质干细胞中明显下调,且通过KEGG以及GO富集分析发现THSD4基因可能与PI3K-AKT信号通路及Wnt信号通路相关。随着成骨诱导分化时间的延长,THSD4 mRNA和成骨分化标志性基因（ALP、Runx2、Osx）mRNA在MC3T3-E1以及M-BMSC中表达量均逐渐增加。过表达THSD4可以增强MC3T3-E1细胞和M-BMSC的成骨分化能力,而敲减THSD4则减弱了MC3T3-E1细胞和M-BMSC的成骨分化能力。结论 THSD4基因在绝经后骨质疏松症患者骨髓间充质干细胞中明显下调,且THSD4基因可以增强MC3T3-E1细胞以及M-BMSC的成骨分化能力。     

Murine osteoblastlike cells and the osteogenic cell MC3T3-E1 release a macrophage colony-stimulating activity in culture

Summary The osteoclast may be of hematopoietic lineage and as such its development could be regulated by colony-stimulating factors. Since there is much interest as to whether osteoblasts influence bone resorption, we examined whether bone cells produce colony-stimulating activity. Both cells isolated from neonatal calvaria and the osteogenic cell MC3T3-E1 were found to constitutively release a colony-stimulating activity possessing characteristics of a macrophage colony-stimulating factor, as determined by basic biochemical purification and by identity of colonies induced in cultures of bone marrow cells. Release could be increased by the presence of the bone-resorbing agents lipopolysaccharide and 1,25 dihydroxyvitamin D₃. We conclude that the osteoblast may contribute to both the processes of osteoclast formation and of hematopoiesis through the secretion of colony-stimulating activity into the adjacent bone marrow.     

Stimulation by 1,25-dihydroxyvitamin D3 of in vitro mineralization induced by osteoblast-like MC3T3-E1 cells

Although vitamin D is essential for mineralization of bone, it is as yet unclear whether vitamin D has a direct stimulatory effect on the bone mineralization process. In the present study, the effect of 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] on in vitro mineralization mediated by osteoblast-like MC3T3-E1 cells was examined. MC3T3-E1 cells continued to grow after they reached confluency, and DNA content and alkaline phosphatase activity increased linearly until about 16 days of culture, whereas 45Ca accumulation into cell and matrix layer remained low. After this period, DNA content plateaued, and 45Ca accumulation increased sharply. Histological examination by von Kossa staining revealed that calcium was accumulated into extracellular matrix. In addition, needle-shaped mineral crystals similar to hydroxyapatite crystals could be demonstrated in between collagen fibrils by electron microscopy. Thus, MC3T3-E1 cells differentiate in vitro into cells with osteoblastic phenotype and exhibit mineralization. When MC3T3-E1 cells were treated with 1,25(OH)2D3 at this stage of culture, there was a dose-dependent stimulation of 45Ca accumulation by 1,25(OH)2D3, and a significant stimulation of 45Ca accumulation was observed with 3 x 10(-10) M 1,25(OH)2D3. Although 1,25(OH)2D3 enhanced alkaline phosphatase activity and collagen synthesis at the early phase of culture, it did not affect any of these parameters at the late phase when 1,25(OH)2D3 stimulated mineralization. Neither 24,25-dihydroxyvitamin D3 nor human PTH(1-34) affected mineralization in the presence or absence of 1,25(OH)2D3. These results demonstrate that 1,25(OH)2D3 stimulates matrix mineralization induced by osteoblastic MC3T3-E1 cells, and are consistent with the possibility that 1,25(OH)2D3 has a direct stimulatory effect on bone mineralization process.(ABSTRACT TRUNCATED AT 250 WORDS)     

镁锌合金在体外对MC3T3-E1细胞增殖、分化和矿化的影响

目的 观察镁锌合金(Mg-zn)在体外的降解及对小鼠前成骨细胞(MC313-E1)增殖、分化和矿化的影响,探讨Mg-Zn成为新型骨科内植物材料的可行性.方法 Mg-Zn和纯镁(Mg)试样置入模拟体液(SBF)中,3 d后通过电化学方法和静态浸泡失重的方法来测定其腐蚀电位及腐蚀速率;在Mg-Zn上接种MC3T3-E1细胞,采用噻唑蓝(MTT)比色法检测1、3、5、7、9 d时细胞增殖活性,采用碱性磷酸酶(ALP)检测试剂盒检测14、28 d时细胞ALP活性,并用四环素荧光染色检测14d时矿化结节.与左旋聚乳酸(PLLA)作对照研究.结果 Mg-Zn的腐蚀电位增高,腐蚀速率降低;培养第5、7、9天后,Mg-Zn成骨细胞增殖活性明显高于PLLA(P<0.01);14、28 d时,Mg-Zn ALP活性明显高于PuA(P<0.01);Mg-Zn矿化结节面积明显大于PLLA(P<0.01).结论 Mg-Zn明显改善了Mg的耐腐蚀性能,同时能促进MC333-E1细胞的增殖、分化和矿化功能,具有良好的生物相容性.     

镁锌合金在体外对MC3T3-E1细胞增殖、分化和矿化的影响

目的 观察镁锌合金(Mg-zn)在体外的降解及对小鼠前成骨细胞(MC313-E1)增殖、分化和矿化的影响,探讨Mg-Zn成为新型骨科内植物材料的可行性.方法 Mg-Zn和纯镁(Mg)试样置入模拟体液(SBF)中,3 d后通过电化学方法和静态浸泡失重的方法来测定其腐蚀电位及腐蚀速率;在Mg-Zn上接种MC3T3-E1细胞,采用噻唑蓝(MTT)比色法检测1、3、5、7、9 d时细胞增殖活性,采用碱性磷酸酶(ALP)检测试剂盒检测14、28 d时细胞ALP活性,并用四环素荧光染色检测14d时矿化结节.与左旋聚乳酸(PLLA)作对照研究.结果 Mg-Zn的腐蚀电位增高,腐蚀速率降低;培养第5、7、9天后,Mg-Zn成骨细胞增殖活性明显高于PLLA(P<0.01);14、28 d时,Mg-Zn ALP活性明显高于PuA(P<0.01);Mg-Zn矿化结节面积明显大于PLLA(P<0.01).结论 Mg-Zn明显改善了Mg的耐腐蚀性能,同时能促进MC333-E1细胞的增殖、分化和矿化功能,具有良好的生物相容性.