To evaluate the sealing potential of self-designed root canal filling material made of calcium phosphate cement (alpha-TCP/TTCP, CPC), the apices of root canals of six adult dogs were purposely perforated and enlarged up to the No 40 instrument. Then CPC was used to fill the root canal. Mean while either calcium hydroxide (Ca(OH)2) paste or hydroxyapatite (HA) paste was used as control. The animals were killed at 4, 12, 20 weeks postoperatively. The different materials about ways of apical closure, restoration periapocal tissues and adaptability to the dentinal surface were observed by histomorphology and scanning electron microscopic. This study revealed that CPC had excellent biocompatibility and adaptability to the dentinal wall. Its osteoconduction can promote the formation of calcific barriers and healing of periapical tissue. The apex can be closed completely. Compared with the control pastes it has advantages of ease of manipulation and better sealing capability. The results showed that CPC could be used as a root canal filling material for pupless teeth with open apex and destructive periapical tissue.
Animals ; Calcium Phosphates ; pharmacology ; Dogs ; Root Canal Filling Materials ; pharmacology ; Root Canal Therapy

Tooth decay is prevalent, and secondary caries causes restoration failures, both of which are related to demineralization. There is an urgent need to develop new therapeutic materials with remineralization functions. This article represents the first review on the cutting edge research of poly(amido amine) (PAMAM) in combination with nanoparticles of amorphous calcium phosphate (NACP). PAMAM was excellent nucleation template, and could absorb calcium (Ca) and phosphate (P) ions via its functional groups to activate remineralization. NACP composite and adhesive showed acid-neutralization and Ca and P ion release capabilities. PAMAM+NACP together showed synergistic effects and produced triple benefits: excellent nucleation templates, superior acid-neutralization, and ions release. Therefore, the PAMAM+NACP strategy possessed much greater remineralization capacity than using PAMAM or NACP alone. PAMAM+NACP achieved dentin remineralization even in an acidic solution without any initial Ca and P ions. Besides, the long-term remineralization capability of PAMAM+NACP was established. After prolonged fluid challenge, the immersed PAMAM with the recharged NACP still induced effective dentin mineral regeneration. Furthermore, the hardness of pre-demineralized dentin was increased back to that of healthy dentin, indicating a complete remineralization. Therefore, the novel PAMAM+NACP approach is promising to provide long-term therapeutic effects including tooth remineralization, hardness increase, and caries-inhibition capabilities.
Amines ; pharmacology ; Calcium ; Calcium Phosphates ; chemistry ; pharmacology ; Dentin ; chemistry ; Humans ; Nanocomposites ; chemistry ; Nanoparticles ; Tooth Remineralization ; methods

OBJECTIVETo test the different contrctile responses of extracellular nucleotides, such as ATP, UTP and nucleotide uridine adenosine tetraphosphate (Up4A) in gastric longitudinal muscle (LM) and circular muscle (CM). Examined the effect of P2X and P2Y receptor antagonists (in this study, we used IP5I and suramin) and cyclooxygenase inhibitor (indomethacin) on Up4A induced contractile responses in LM and CM.

METHODSThe rats were sacrificed and the stomachs were opened to gain LM and CM. Using organ bath system to assess contrctile responses of smooth muscle.

RESULTSUp4A could induce contractile responses in both CM and LM, which were similar with ATP and UTP. IP5 did not attenuate Up4A could induce contractions in both LM and CM, but suramin and indomethacin significantly inhibited Up4A contraction in CM, but not in LM.

CONCLUSIONOur results suggest that extracellular nucleosides and their inhibitors induce different responses between LM and CM.

Adenosine Triphosphate ; pharmacology ; Animals ; Dinucleoside Phosphates ; pharmacology ; Indomethacin ; Muscle Contraction ; Muscle, Smooth ; physiology ; Nucleotides ; pharmacology ; Rats ; Suramin ; Uridine Triphosphate ; pharmacology

Poor stability existed in the anaphase of the high-cell-density fermentation of Saccharomyces crevisiae for S-adenosyl-L-methionine (SAM) production in 5 L fermentor. To improve the fermentation stability, we studied the addition of diammonium hydrogen phosphate, sodium glutamate and adenosine disodium triphosphate into glucose feeding solution. Study of four fed-batch cultures showed that, after 34 h fermentation, when dry cell weight reached 100 g/L, the addition of 50 g pre-L-methionine and glucose feeding with 10 g/L adenosine disodium triphosphate was optimal for SAM production. Under this condition, after 65.7 h fermentation, both the dry cell weight and the yield of SAM reached the maximum, 180 g/L and 17.1 g/L respectively.
Adenosine Triphosphate ; pharmacology ; Fermentation ; Phosphates ; pharmacology ; S-Adenosylmethionine ; biosynthesis ; genetics ; Saccharomyces cerevisiae ; enzymology ; genetics ; Sodium Glutamate ; pharmacology

OBJECTIVETo investigate the effect of phosphoinositide 4-phosphate (PI4P) on human glioma U87 cells and the mechanism of action of PI4P in the development of human glioma through the overexpression or silencing of PI4P in human glioma U87 cells, and to provide a new target for basic research and clinical treatment of glioma.

METHODSLV-Helper1, LV-Helper2, pWPXLd-PI4P, and pLL3.7-shPI4P were used to package pWPXLd-PI4P and pLL3.7-shPI4P lentiviruses. The U87-GFP (PI4P-overexpression control group), U87-GFP-PI4P (PI4P-overexpression experimental group), U87-Scramble (PI4P-silencing control group), and U87-shPI4P (PI4P-silencing experimental group) cell lines were established. Wound-healing assay and Transwell assay were used to evaluate cell migration and invasion, and Western blot was used to measure the expression of PI4P in each group.

RESULTSWestern blot detected the expression of exogenous PI4P in the U87-GFP-PI4P cell line, and the U87-shPI4P cell line showed reduced expression of PI4P compared with the U87-Scramble cell line in the control group. The U87-GFP-PI4P cell line with PI4P overexpression had a significantly stronger ability of migration than the U87-GFP cell line in the control group (P<0.01); the U87-shPI4P cell line with PI4P silencing had a reduced ability of migration than the U87-Scramble cell line in the control group (P<0.01). The U87 cell line with PI4P overexpression had a significantly stronger invasion ability than the control group (P<0.05); after PI4P silencing, the experimental group showed a significant reduction in invasion ability compared with the control group (P<0.05).

CONCLUSIONSIn human glioma U87 cells, PI4P can promote the invasion and migration of glioma cells and may become a new target in the basic research and clinical treatment of glioma.

Cell Line, Tumor ; Cell Movement ; drug effects ; Glioma ; pathology ; Humans ; Neoplasm Invasiveness ; Phosphatidylinositol Phosphates ; pharmacology

BACKGROUNDBiphasic calcium phosphate (BCP) ceramics has a potential advantage as an osteoconductive matrix and has an optimal resorption rate for bone formation. Using BCP ceramics as a bone graft during spinal fusion requires osteogenesis within the material and subsequent bridging between adjacent vertebrae to provide long-term support. Bisphosphonates have been reported to prolong the process of bone healing. The influence of bisphosphonate treatment on bone formation within BCP ceramics in spinal fusion remains unknown. The aim of this study was to evaluate the influence of alendronate on BCP osteogenesis in posterolateral spinal fusion.

METHODSPosterolateral spinal fusion with pedicle screw fixation was performed at the lumbar spine in twenty-two pigs. BCP ceramics were applied as a bone graft to obtain bone fusion between adjacent transverse processes. Eleven pigs in the treatment group received oral alendronate 10 mg/d for three months postoperatively. Eleven pigs in the control group did not receive treatment with alendronate. All animals underwent posterolateral spinal fusion with BCP ceramics. The fusion rate was evaluated three months after the operation.

RESULTSThe fusion rates evaluated by X-ray were 27.3% in the treatment group and 20% in the control group. The fusion rates using histological evaluation were 18.2% in the treatment group and 20% in the control group. The mean volumes of fusion mass were (3.64 +/- 0.86) cm(3) in the treatment group and (4.26 +/- 0.63) cm(3) in the control group. No significant differences were found in either trabecular bone volume or residual BCP volume between treatment and control groups using histological evaluation. The new bone formation within BCP ceramics was greater in the area adjacent to transverse process (P < 0.01).

CONCLUSIONOral alendronate with a dose of 10 mg daily do not inhibit bone formation within BCP ceramics or affect the fusion rate in posterolateral spinal fusion from porcine models.

Alendronate ; pharmacology ; Animals ; Calcium Phosphates ; chemistry ; Ceramics ; chemistry ; Female ; Osteogenesis ; drug effects ; Spinal Fusion ; Swine

The effect of inorganic phosphate on cell growth, accumulation of polysaccharides together with nutrient utilization was investigated in suspension cultures of protocorm-like bodies of Dendrobium huoshanense. Thirty-day-old cells were transferred into liquid medium with the inoculum density of 100 g/L cells. The results indicate that the optimal concentration of phosphate in medium for cell growth of protocorm-like bodies of Dendrobium huoshanense was 2.5 mmol/L and biomass was 496.5 g/L (fresh weight). Phosphate was a limited factor for cell growth and there was relationship between the levels of intracellular phosphate and cell growth. 2.5 mmol/L of medium phosphate was beneficial to the absorption of carbohydrate and nitrate source. 0.312 mmol/L of medium phosphate was better for accumulation of polysaccharides and production of polysaccharides was 2.22 g/L at 36 d.
Cell Proliferation ; drug effects ; Dendrobium ; growth & development ; metabolism ; Phosphates ; metabolism ; pharmacology ; Polysaccharides ; biosynthesis ; Suspensions

A novel unsaturated polyphosphoester (UPPE) was devised in our previous research, which is a kind of promising scaffold for improving bone regeneration. However, the polymerization process of UPPE scaffolds was unfavorable, which may adversely affect the bioactivity of osteoinductive molecules added if necessary, such as recombinant human bone morphogenetic protein-2 (rhBMP2). The purpose of this study was to build a kind of optimal scaffold named UPPE-PLGA-rhBMP2 (UPB) and to investigate the bioactivity of rhBMP2 in this scaffold. Furthermore, the cytotoxicity and biocompatibility of UPB scaffold was assessed in vitro. A W1/O/W2 method was used to fabricate PLGA-rhBMP2 microspheres, and then the microspheres were added to UPPE for synthesizing UPB scaffold. The morphological characters of PLGA-rhBMP2 microspheres and UPB scaffolds were observed under the scanning electron microscopy and laser scanning confocal microscopy. The cumulative release of UPB scaffolds was detected by using ELISA. The cytotoxicity and biocompatibility of UPB scaffolds were evaluated through examining the adsorption and apoptosis of bone marrow stromal cells (bMSCs) seeded on the surface of UPB scaffolds. The bioactivity of rhBMP2 in UPB scaffolds was assessed through measuring the alkaline phosphates (ALP) activity in bMSCs seeded. The results showed that UPB scaffolds sequentially exhibited burst and sustained release of rhBMP2. The cytotoxicity was greatly reduced when the scaffolds were immersed in buffer solution for 2 h. bMSCs attached and grew on the surface of soaked UPB scaffolds, exerting well biocompatibility. The ALP activity of bMSCs seeded was significantly enhanced, indicating that the bioactivity of rhBMP2 remained and still took effect after the unfavorable polymerization process of scaffolds. It was concluded that UPB scaffolds have low cytotoxicity, good biocompatibility and preserve bioactivity of rhBMP2. UPB scaffolds are promising in improving bone regeneration.
Bone Morphogenetic Protein 2 ; chemistry ; pharmacology ; Bone Regeneration ; drug effects ; Humans ; Lactic Acid ; chemistry ; pharmacology ; Phosphatidylinositol Phosphates ; chemistry ; pharmacology ; Polyglycolic Acid ; chemistry ; pharmacology ; Tissue Scaffolds

This study was designed to assess the feasibility of calcium phosphate cement/amifostine complex as a new material for filling the bone defect caused by tumor resection. Mixed-molding method was used, the mass ratios of 0%, 0.1%, 0.5%, 1%, 2% of amifostine/calcium phosphate cement complex being adopted. The curing time, mechanical strength, porosity, scanning electron micrograph, osteosarcoma cells' vitality and vascular endothelial cells' vitality relevant to the complex in vitro were observed. Calcium phosphate cement being loaded with 0.1% and 0.5% amifostine did not affect the curing time, strength, pore size and porosity of calcium phosphate bone cement. In addition proliferation and differentiation of osteosarcoma cells and vascular endothelial cells were not affected. These data suggest that phosphate cement containing 0.1% and 0.5% amifostine be of significance in the treatment regimen as bone defect filling materials..
Amifostine ; pharmacology ; Bone Cements ; pharmacology ; Calcium Phosphates ; pharmacology ; Cell Line, Tumor ; Cell Survival ; drug effects ; Cells, Cultured ; Chemical Phenomena ; Endothelial Cells ; cytology ; drug effects ; Humans ; Osteosarcoma ; pathology

*Absorbable Implants ; Biocompatible Materials/*pharmacology ; Bone Regeneration/*drug effects ; Bone Regeneration/physiology ; Bone Substitutes/*pharmacology ; Calcium Phosphates/*pharmacology ; Structure-Activity Relationship