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Objective:To establish ion chromatography(IC) method for determination of the content of sodium glycerophosphate and phosphate salts in concentrated divitamins and sodium phosphate syrup. Methods:An AG19 -HC (50 mm× 4 mm) guard col-umn and an IonPac AS18 -HC (250 mm × 4 mm) ion analysis column were used, potassium hydroxide solution was applied as the mobile phase with gradient elution,and a conductance detector was used with suppression conductometric detection. Results:Sodium glycerophosphate and phosphate could be separated well under the chromatographic conditions. The linear range was 1.054-84.35 μg ·ml-1(r=0.999 4)for sodium glycerophosphate and 0.316 8-25.35 μg·ml-1(r=0.999 8)for phosphate. The average recovery was 99.35% (RSD=1.16%,n=9) and 98.96%(RSD=2.61%,n=9), respectively.Conclusion: The method is simple, rapid and accurate,and can be used for the quality control of concentrated divitamins and sodium phosphate syrup.
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OBJECTIVE: To prepare lappaconitine (LA)-loaded chitosan/sodium β-glycerophosphate (CS/β-GP) thermosensitive hydrogels and investigate its phase transition mechanism of gel formation process and release properties in vitro. METHODS: The injectable CS/β-GP thermosensitive hydrogels were prepared with biodegradable CS as carrier material and β-GP as coagulation accelerator.The release behavior in vitro was studied by dynamic dialysis, and the phase transition mechanism of gel formation process was further investigated by rheologieal method. RESULTS: The optimized process condition was as follows;the concentration of β-GP and CS was 560 and 22 mg·mL-1, respectively, CS was dissolved by 0.1 mol·L-1 HOAc, and the valume ratio of CS to β-GP was 8.75:1.25 (V/V), the gelation time of CS/β-GP thermosensitive hydrogels with volume ratio of 8.75:1.25 (V/V) at 37℃ was 5 min 38 s.The in vitro release study showed that these injectable CS/β-GP thermosensitive hydrogels had sustained release effect for LA, and the release behavior could be well described by the Higuchi model and Korsmeyer-Peppas model.The mechanism of LA releasing from CS/β-GP thermosensitive hydrogels was attributed to drug dissolution and diffusion.Rheologieal studies showed that the CS/β-GP thermosensitive hydrogels belonged to thixotropic system and exhibited non-Newtonian and shear-thinning fluid behavior as well as "solid-like" gelatin behavior. CONCLUSION: LA-Loaded CS/β-GP injectable thermosensitive hydrogels with good elasticity and gel strength properties are prepared successfully, and they show sustained release effect of LA in vitro.
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By developing a rapid gelation chitosan (CS) /β-glycerophosphate (β-GP) thermosensitive hydrogel containing Kuijiean, to decrease the loss of drug and confirm the capabilities of the drug delivery. Thermosensitive hydrogel was a carrier, gel time was chosen in this study as the index to investigate the effect of β-GP concentration, pH value, and temperature on the thermosensitive hydrogel by single factor experiments. The properties of the hydrogel were characterized regarding shape and surface morphology by using scaning electron microscopy (SEM); The chemical structure diversification of hydrogels upon gelation was charactered by FTIR spectrometer. By the experiments of the drug loaded thermosensitive hydrogel to deliver drug in vitro, the diversification of the capabilities of the drug delivery was evaluated. The temperature of Kuijiean thermosensitive hydrogel was (37.0 ± 4.5) ℃, by which the sol gel could transform into semi-solid gel at (6.00 ± 0.82) min, the drug release rate slowed down obviously, and the cumulative release rate was only (67.78 ± 0.35)% (n = 3) by 24 h, while the cumulative release rate of the equal quantity of raw material drug was (90.43 ± 0.62)% (n = 3) by 24 h. The release behavior was close to the Weibull model, the drug release mechanism was a double mechanism combining drug diffusion and gel erosion. It is true that achieves the transformation of Kuijiean from sol to semi-solid gel at 37.0 ℃. The CS/β-GP gel system allows the sustained release of the Kuijiean.
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Objective To explore the effect of vitamin K2 on β-glycerophosphate(β-GP)-induced rat vascular smooth muscle cells (VSMCs) calcification and and the mechanism.Methods VSMCs were obtained from rat aortic,and identified by immunocytochemistry,then randomly divided into control group,high phosphorus group,vitamin K2 group (the group was settled three subgroups according to the concentration of vitamin K2 based on the high phosphorus medium,namely 10 μmol/L,25 μmol/L,50 μmol/L) and noggin (bone morphogenetic protein pathway inhibitor) group.Calcification was visualized by Alizarin red staining,calcium load in cells was quantified by o-cresolphthalein complexone method and alkaline phosphatase (ALP) activity was measured after stimulating 14 days,gene expressions of bone morphogenetic protein-2 (BMP-2),SMAD1,SMAD7 and Runx2 mRNA were detected by RT-PCR,Runx2 protein levels was detected by Western blotting after stimulating 3 days.Results Compared with the cells in control group,high phosphorus induced cell calcification,increased ALP activity,up-regulated the expression of BMP-2,SMAD1,Runx2 mRNA (P ＜ 0.05) and down-regulated the expression of SMAD7 (P ＜ 0.01),while compared with high phosphorus group,the calcium deposition,ALP activity and the expression of BMP-2,SMAD1,Runx2 mRNA were remarkably reduced in a dose-dependent manner by treatment with vitamin K2 (P ＜ 0.05) and the expression of SMAD7 was increased (P ＜ 0.01).Compared with high phosphorus group,SMAD1 and Runx2 expression in noggin group were remarkably reduced(P ＜ 0.01).Conclusion Vitamin K2 inhibits β-glycerophosphate-induced VSMCs calcification which correlates with the suppression of the expression of osteoblast markers through the down-regulation of bone morphogenetic protein pathway.
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Objective To explore the effect and mechanism of magnesium on calcification induced by hyperphosphate.Methods Vascular smooth muscle cells (VSMCs) were primarily cultured in vitro and induced calcification by β-glycerophosphate (β-GP).VSMCs were randomly divided into control group,high phosphorus group (10 mmol/L β-GP),magnesium intervèntion group(10 mmol/L β-GP + 3 mmol/L MgSO4) and 2-aminoethoxy-diphenylborate (2-APB,an inhibitor of magnesium transporter) intervention group(10 mmol/L β-GP+3 mmol/L MgSO4+ 10-4 mol/L 2-APB).Calcium deposition and alkaline phosphatase (ALP) activity were measured by alizarin red staining,quantification of calcium and euzyme linked immunosorbent assay.RT-PCR and Western blotting were used to observe the expression of core binding factor α-1 (Cbfα-1) mRNA and protein,respectively.In vivo,male Sprague-Dawley rats (n=24) were randomly divided into control group (methylcellulose+high phosphorous diet),vascular calcification group (adenine suspension + high phosphorous diet),high magnesium intervention group(adenine suspension+high phosphorous and magnesium diet).The aortic pulse wave velocity (PWV) was measured,and vascular calcification was determined by von Kossa stain and quantification of calcium.Cbfα-1 in aortic was measured by immunohistochemistry.Results In vitro,compared with high phosphorus group,calcification,ALP activity (P ＜ 0.05) and Cbfα-1expression in VSMCs were significantly decreased in magnesium intervention group after incubation for 14 days,but the addition of 2-APB might inhibit the protective effect of magnesium on VSMCs.Dynamic observation of Cbfα-1 showed that magnesium significantly inhibited the expression of Cbfα-1 (P ＜ 0.05) on the third day and the inhibitory role was obviously increased in a time-dependent manner.Consistent with the findings in vitro,the aortic PWV,calcification were all significantly reduced (P ＜ 0.05) in high magnesium intervention group with high serum magnesium level,when compared with vascular calcification group.Immunohistochemistry showed that hypermagnesemia downregulated obviously the expression of Cbfα-1 induced by hyperphosphatemia(P ＜ 0.05).Conclusion Magnesium protects against vascular calcification by inhibiting osteogenic differentiation of VSMCs.
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Objective To explore the effects of the different concentrations of magnesium ions on vascular smooth muscle cell (VSMC) calcification in rats. Methods VSMCs were obtained from rat aortic, and were identified by immunocy-tochemistry. VSMCs were then randomly divided into control group, high phosphorus group and magnesium intervention group. VSMCs were cultured with 10%fetal bovine serum in control group. VSMCs were cultured with high phosphorus in high phosphorus group. VSMCs were cultured with different concentrations of magnesium chloride based on the high phos-phorus medium in magnesium intervention group (final concentrations of magnesium ions were 1, 2 and 3 mmol/L). The calci-um content and alkaline phosphatase(ALP)activity were measured after the stimulation for 7 days. The expression of Cbfα1 mRNA was detected by RT-PCR. Results Compared with control group, calcium deposits were found significantly higher in high phosphorus group and magnesium intervention group. The calcified nodules gradually reduced with the increased magnesium ion concentration in the intervention group. The calcium contents were significantly lower in the intervention groups (2 and 3 mmol/L) compared with those of high phosphorus group (P<0.05), but no difference was found between 1 mmol/L magnesium intervention group and high phosphorus group. There were no significant differences in the ALP activity and Cbfα1 mRNA expression between intervention groups (2 and 3 mmol/L) and control group (P<0.05). The ALP activity and the expression of Cbfα1 mRNA were gradually decreased with the increased magnesium ion concentration in the inter-vention group, and which were lower than those of high phosphorus group (P<0.05). Conclusion Magnesium can reduce calcification and osteoblastic transdifferentiation, which may be achieved by reducing the expression of Cbfα1 in VSMCs.
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OBJECTIVE: To synthesis chitosan/β-glycerophosphate (CS/β-GP) thermosensitive hydrogel containing multi-walled carbon nanotubes-polyethyleneimine (MWCNTs-PEI) complexes and to lay a foundation for further research of dual slow-release delivery system. METHODS: Chitosan thermosensitive hydrogel containing MWCNTs-PEI was prepared by MWCNTs-PEI dispersed to the chitosan thermosensitive hydrogel. As the indicator of the gelling time, the experiment studied the effect of β-GP concentration, pH, temperature and MWCNTs-PEI composite quality on the thermosensitive chitosan hydrogel, and then it was charactered by using transmission electron microscopy (SEM), infrared spectrometer(IR), and initially investigated in vivo compatibility. RESULTS: The dynamic rheology method investigated the gelling temperature were about 37.0°C. Within a certain range, the gelling time of thermosensitive chitosan hydrogel was shortened with the increase of concentration of β-GP, pH, temperature, and the quality of MWCNTs-PEI complexes, and they could be transformed into the hydrogel in vivo. The addition of MWCNTs-PEI complex didn't react chemically with the thermosensitive chitosan hydrogel and significantly make the holes of the chitosan thermosensitive hydrogel smaller by SEM and FT-IR, eventually leading to the swelling rate and the corrosional ratio decrease. CONCLUSION: Chitosan/β-glycerophosphate thermosensitive hydrogel containing amino-carbon nanotubes has a rapid gelation and good temperature-sensitivity, which can serve as a good double sustained-release carrier.
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OBJECTIVE: This in vitro study evaluated the effect of calcium glycerophosphate (CaGP) supplemented to soft drinks on bovine enamel erosion. MATERIAL AND METHODS: Four pH-cycles were performed, alternating demineralization by the beverage and remineralization in artificial saliva. RESULTS: Mean wear (±SD, µm) was 7.91±1.13, 7.39±1.01, 7.50±0.91 and 5.21±1.08 for Coca-Cola® without CaGP or containing CaGP at 0.1, 1.0 or 2.0 mM, respectively, while no wear was detected for CaGP at 5.0 and 10.0 mM. Corresponding figures for Sprite Zero® without CaGP or containing CaGP at 0.1, 1.0, 2.0, 5.0 or 10.0 mM were 8.04±1.30, 7.84±0.71, 7.47±0.80, 4.96±0.81, 3.99±0.10 and 1.87±0.12, respectively. CONCLUSION: Supplementation of both beverages with CaGP seems to be an alternative to reduce their erosive potential.
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Animals , Cattle , Carbonated Beverages/adverse effects , Dental Enamel/drug effects , Glycerophosphates/pharmacology , Tooth Erosion/prevention & control , Dental Enamel/chemistry , Hardness , Materials Testing , Random Allocation , Saliva, Artificial , Surface Properties , Tooth Erosion/chemically induced , Tooth Wear/prevention & controlABSTRACT
The purpose of this study is to investigate the response of human pulp cell on Portland cement mixed with beta-glycerophosphate. To investigate the effect of beta-glycerophosphate and/or dexamethasone on human pulp cell, ALP activity on various concentration of beta-glycerophosphate and dexamethasone was measured and mineral nodule of human pulp cell was stained with Alizarin red S. MTS assay and ALP activity of human pulp cell on Portland cement mixed with various concentration of beta-glycerophosphate (10 mM, 100mM, 1M) was measured and the specimens were examined under SEM. Addition of beta-glycerophosphate or dexamethasone alone had no effect however, the addition of 5 mM beta-glycerophosphate and 100 nM dexamethasone had the largest increasement in ALP activity. There was no toxicity in all samples and the data showed that Portland cement mixed with 10 mM beta-glycerophosphate had more increase in ALP activity compared with control. In conclusion, Portland cement mixed with beta-glycerophosphate has no toxicity and promotes differentiation and mineralization of pulp cell compared with additive-free Portland cement. This implicated that application of Portland cement mixed with beta-glycerophosphate might form more reparative dentin and in turn it would bring direct pulp capping to success.
Subject(s)
Humans , Anthraquinones , Dental Pulp Capping , Dentin , Dexamethasone , GlycerophosphatesABSTRACT
Objective To establish an in vitro vascular calcification model of bovine aortic smooth muscle cell(BASMC) induced by ?-glycerophosphate.Methods: Primary BASMCs were obtained by the explant method.The cells after 4～8 passages were incubated in the medium containing(10 mmol/L) ?-glycerophosphate for 10 days to induce calcification.Calcification were observed in cultures by Alizarin Red S and Von Kossa stain and transmission electron microscopy.Meanwhile,calcium deposition,alkaline phosphatase(ALP) activity of cell layer and osteocalcin(OC) in culture supernatant were measured.Results After 10 days,extensive calcium deposition was detected by Von Kossa and alizarin red S stain and transmission electron microscopy.?-glycerophosphate increased calcium deposition in a time-dependent manner,ALP activity and OC concentration were higher than that of uncalcified controls at various time points(P
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Objective To observe the biological behavior of chondrocytes in chitosan based hydrogel in vitro and to evaluate the possibility of chitosan and glycerophosphate mixed gel using as injectable scaffolds in tissue engineering.Methods A novel injectable thermosetting gel was made of chitosan and glycerophosphate mixture.Chondrocytes isolated by enzymic digestion from the articular cartilage of the young rabbits aged 3-4 weeks were cultured in monolayer system.After primary culture and subculturing,the cells were seeded in chitosan based gel in concentration of 5?10~7/ml in vitro.Characteristics of chondrocytes during 4-week culture were observed with invert microscope.MTT was used to detect the seed growth after one-week culture.In 4th week,after haematoxylin eosine and toluidine blue staining,the artifical cartilage was performed type Ⅱ collagen immunohistochemistry and observed by scanning electron microscope.Results Chondrocytes retained their round morphology,multiplied,and produced matrix in chitosan and glycerophosphate mixture gels.The results of immunohistochemistry were strongly positive.Conclusion That most chondrocytes appeared to occupy large areas of rough chitosan based gels,guarantees a suitable environment where chondrocytes secrete matrix macromolecules and preserve their round morphology in vitro.Chitosan and glycerophosphate mixture gel may be a vehicle for injectable tissue-engineered cartilage.
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OBJECTIVE:To prepare temperature sensitive hydrogel which is of strength.METHODS:The hygrogel was prepared using CS,PVA and GP as matrix with concentration of CS(A),weight ratio of CS to PVA(B) and pH value(C) as factors and with initial gelatination temperature,strength and dehydration as indexes.The formula was optimized by orthogonal experiment and verified.RESULTS:The optimal formula was as follows:A 20 mg?mL-1,B 1 :1,C 7.2.The prepared hydrogel was fluid at 4 ℃ or room temperature while gelatinized at 37 ℃ within 10 min with strength of about 1.4 kPa.Gelatination time reduced along with the increase of temperature.The pH value had hardly changed during degradation in vitro within 28 d.CONCLUSION:The CS/PVA/GP hydrogel is simple and practical in preparation technique and is temperature sensitive and of strength.
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Neurospora crassa Em 5297a can utilize sodium β-glycerophosphate as a sole phosphorous source (in the place of KH2PO4). Under these conditions a repressible alkaline phosphatase is elaborated which has different pH optimum towards β-glycerophosphate (10.2) and pyrophosphate (9.0) as substrates. This enzyme does not require any metal ion for its activity and could be assayed in the presence of EDTA. However, under conditions of cobalt toxicity, the activity of this enzyme is high and is decreased in copper and nickel toxicities.