Solubility and Ingrowth Behaviour of Degradable and Figuline Calcium Alkaline Phosphate Cements

2011 ◽  
Vol 493-494 ◽  
pp. 387-390 ◽  
Author(s):  
F. Dombrowski ◽  
Heidi Marx ◽  
Ute Ploska ◽  
D. Nicolaides ◽  
M. Stiller ◽  
...  

The thrust of the investigations presented here is to point out the degradation behaviour in vitro and the ingrowth behaviour in vivo of four different calcium alkaline phosphate cements. Two of the figuline and mouldable composites consist of the crystalline phase Ca2KNa(PO4)2 and two of the crystalline phase Ca10[K/Na](PO4)2 each containing 2wt% medium gel strength porcine gelatin. Furthermore Α-TCP was added to both Ca10[K/Na](PO4)2 cements as a hardening supporting reactant. The testing material groups differ in small amorphous portions containing either silica phosphate (GB9), magnesium potassium phosphate (GB14) or diphosphates (401545 and 401545(70)). The respective composites show a monomodal particle size distribution (d50~7µm; span~4) and an average total porosity around 28vol%.For the solubility studies cylindrical samples (d=6mm; h=12mm) were stored in a 0.1mol TRIS buffer solution and incubated at 37°C for maximum 50 weeks. The storage solution was analysed and renewed every week. The results are plotted cumulative. For the in vivo studies critical size defects were dissected to mandibles in a sheep model in which a 1cm3 area of the bottom of the mandibles was surgically resected and replaced with the figuline cements whereas the mouldability allows the reconstruction of the original outer contour without draining off even when replacing upside down.

1987 ◽  
Vol 42 (11) ◽  
pp. 1451-1460 ◽  
Author(s):  
Peter Nielsen ◽  
Bernd Dresow ◽  
Hellmuth C. Heinrich

We synthesized a varicty of colloidal and non-colloidal mixed hexacyanoferrate(II) complexes of Fe. Cu. Co. Ni. Zn. Mn and studied ihe cesium Sorption in vitro under physiological conditions (artificial gastric juice. pH 1.2 and artificial duodenal juice. pH 6.8). All of the hexaeyanoferrates under study (except cesium iron(III) hexaeyanoferrate CsFeHCF) sorb tracer amounls of 13 Cs quantitatively. Differences in the sorption capacity become obvious by offering substantial amounts of cesium. Potassium copper hexacyanoferrate(II) (KCuHCF) and potassium zinc hexa- cyanoferrate(II) (KZnHCF) are most efficient in cesium sorption at pH 1.2 and at pH 6.8. The sorption capacities of KCuHCF and KZnHCF (2.3-3.0 mmol Cs'g HCF) are twice as high as for coiloidai Prussian blue (KFeHCF; 1.0-1.3 mmol Cs/g HCF) and insoluble Prussian blue (FeHCF: 1.0-1.6 mmol Cs/g HCF). The most promising Compounds. KCuHCF and KZnHCF. should be further investigated in in vivo studies for 137 |l4cesium decorporation. Evidence indicate that the sorption mechanism for most of the Compounds under study is a cesium/potassium ion-exehange reaction. In the case of insoluble Prussian blue (FeHCF). a cesium/proton exchange was observed. ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ On laboratory scale. 137 |V4Cs-contaminated whey dry powder. produced from South German cow milk in summer 1986 was almost completely decontaminated by dialysing a whey Suspension against buffer Solution containing FeHCF. The 117 "JCs'-ions. completely bound by FeHCF. can be isolatcd from the buffer Solution by simple filtration. The buffer Solution and the FeHCF can


Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1159
Author(s):  
Margarita A. Khimich ◽  
Konstantin A. Prosolov ◽  
Tatiana Mishurova ◽  
Sergei Evsevleev ◽  
Xavier Monforte ◽  
...  

The additive manufacturing of low elastic modulus alloys that have a certain level of porosity for biomedical needs is a growing area of research. Here, we show the results of manufacturing of porous and dense samples by a laser powder bed fusion (LPBF) of Ti-Nb alloy, using two distinctive fusion strategies. The nanostructured Ti-Nb alloy powders were produced by mechanical alloying and have a nanostructured state with nanosized grains up to 90 nm. The manufactured porous samples have pronounced open porosity and advanced roughness, contrary to dense samples with a relatively smooth surface profile. The structure of both types of samples after LPBF is formed by uniaxial grains having micro- and nanosized features. The inner structure of the porous samples is comprised of an open interconnected system of pores. The volume fraction of isolated porosity is 2 vol. % and the total porosity is 20 vol. %. Cell viability was assessed in vitro for 3 and 7 days using the MG63 cell line. With longer culture periods, cells showed an increased cell density over the entire surface of a porous Ti-Nb sample. Both types of samples are not cytotoxic and could be used for further in vivo studies.


2001 ◽  
Vol 5 (8) ◽  
pp. 645-651
Author(s):  
M. Peeva ◽  
M. Shopova ◽  
U. Michelsen ◽  
D. Wöhrle ◽  
G. Petrov ◽  
...  
Keyword(s):  

2005 ◽  
Vol 25 (1_suppl) ◽  
pp. S198-S198
Author(s):  
Joseph R Meno ◽  
Thien-son K Nguyen ◽  
Elise M Jensen ◽  
G Alexander West ◽  
Leonid Groysman ◽  
...  

1994 ◽  
Vol 72 (06) ◽  
pp. 942-946 ◽  
Author(s):  
Raffaele Landolfi ◽  
Erica De Candia ◽  
Bianca Rocca ◽  
Giovanni Ciabattoni ◽  
Armando Antinori ◽  
...  

SummarySeveral “in vitro” and “in vivo” studies indicate that heparin administration may affect platelet function. In this study we investigated the effects of prophylactic heparin on thromboxane (Tx)A2 biosynthesis “in vivo”, as assessed by the urinary excretion of major enzymatic metabolites 11-dehydro-TxB2 and 2,3-dinor-TxB2. Twenty-four patients who were candidates for cholecystectomy because of uncomplicated lithiasis were randomly assigned to receive placebo, unfractionated heparin, low molecular weight heparin or unfractionaed heparin plus 100 mg aspirin. Measurements of daily excretion of Tx metabolites were performed before and during the treatment. In the groups assigned to placebo and to low molecular weight heparin there was no statistically significant modification of Tx metabolite excretion while patients receiving unfractionated heparin had a significant increase of both metabolites (11-dehydro-TxB2: 3844 ± 1388 vs 2092 ±777, p <0.05; 2,3-dinor-TxB2: 2737 ± 808 vs 1535 ± 771 pg/mg creatinine, p <0.05). In patients randomized to receive low-dose aspirin plus unfractionated heparin the excretion of the two metabolites was largely suppressed thus suggesting that platelets are the primary source of enhanced thromboxane biosynthesis associated with heparin administration. These data indicate that unfractionated heparin causes platelet activation “in vivo” and suggest that the use of low molecular weight heparin may avoid this complication.


2020 ◽  
Vol 72 (5) ◽  
Author(s):  
Mario Fadin ◽  
Maria C. Nicoletti ◽  
Marzia Pellizzato ◽  
Manuela Accardi ◽  
Maria G. Baietti ◽  
...  
Keyword(s):  

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