scholarly journals Calcium Phosphate Cement Modified with Silicon Nitride/Tricalcium Phosphate Microgranules

2020 ◽  
Vol 20 (1) ◽  
pp. 56-75
Author(s):  
Lubomir Medvecky ◽  
Radoslava Stulajterova ◽  
Maria Giretova ◽  
Tibor Sopcak ◽  
Maria Faberova ◽  
...  

Abstract Tetracalcium phosphate/monetite biocement was modified with 10 and 30 wt. % addition of highly porous silicon nitride/α-tricalcium phosphate (αTCP) microgranules with various content of αTCP. A composite cement powder mixture was prepared using mechanical homogenization of basic components. The accelerated release of dexamethasone from composite cement was revealed, which indicates their possible utilization for controlled drug release. The wet compressive strength of cements (<17 MPa) was significantly reduced (more than 30%) in comparison with the unmodified cement and both compressive strength and setting time were influenced by the content of αTCP in microgranules. The addition of microgranules caused a 20% decrease in final cement density. Microgranules with a higher fraction of αTCP showed good in vitro SBF bioactivity with precipitation of hydroxyapatite particles. Microstructure analysis of fractured cements demonstrated excellent interconnection between microgranules and cement calcium phosphate matrix, but also showed lower mechanical strength of microgranule cores.

2010 ◽  
Vol 2010 ◽  
pp. 1-14 ◽  
Author(s):  
Rania M. Khashaba ◽  
Mervet M. Moussa ◽  
Donald J. Mettenburg ◽  
Frederick A. Rueggeberg ◽  
Norman B. Chutkan ◽  
...  

New polymeric calcium phosphate cement composites (CPCs) were developed. Cement powder consisting of 60 wt% tetracalcium phosphate, 30 wt% dicalcium phosphate dihydrate, and 10 wt% tricalcium phosphate was combined with either 35% w/w poly methyl vinyl ether maleic acid or polyacrylic acid to obtain CPC-1 and CPC-2. The setting time and compressive and diametral tensile strength of the CPCs were evaluated and compared with that of a commercial hydroxyapatite cement.In vitrocytotoxicity andin vivobiocompatibility of the two CPCs and hydroxyapatite cement were assessed. The setting time of the cements was 5–15 min. CPC-1 and CPC-2 showed significantly higher compressive and diametral strength values compared to hydroxyapatite cement. CPC-1 and CPC-2 were equivalent to Teflon controls after 1 week. CPC-1, CPC-2, and hydroxyapatite cement elicited a moderate to intense inflammatory reaction at 7 days which decreased over time. CPC-1 and CPC-2 show promise for orthopedic applications.


2012 ◽  
Vol 550-553 ◽  
pp. 1133-1138 ◽  
Author(s):  
Rui Juan Xie ◽  
Yang Yang Huang ◽  
Biao Wang ◽  
Meng Zhang

In this study, the high purity tetracalcium phosphate (TTCP) was prepared conveniently after studying the effect of cooling method on the purity of TTCP. The influence of liquid-to-powder (L/P) ratio on the properties of self-setting silk fibroin/calcium phosphate composites was studied. The results showed that the temperature of the furnace had a significant influence on the purity of TTCP when samples were removed from the furnace. Whether using N2 or not had no obvious effect on the purity of TTCP when the temperature declined from 1500°C to 1300°C. The setting time of composites became longer with the increase of L/P ratio in a range 0.32 - 0.39 ml/g, but all less than 15min. The injectability of the composites improved significantly as the L/P ratio increased. The compressive strength of composites reached maximum at the L/P ratio of 0.34 ml/g. The compressive strength decreased with the increase of L/P ratio greater than 0.34ml/g. The L/P ratio had no significant effect on the structure of the composites and the rod-like crystal of hydroxyapatite appeared in all the hardening-body of composites.


2020 ◽  
Vol 11 (4) ◽  
pp. 74
Author(s):  
Lubomir Medvecky ◽  
Radoslava Štulajterová ◽  
Maria Giretova ◽  
Lenka Luptakova ◽  
Tibor Sopčák

(1) Background: The preparation and characterization of novel fully injectable enzymatically hardened tetracalcium phosphate/monetite cements (CXI cements) using phytic acid/phytase (PHYT/F3P) hardening liquid with a small addition of polyacrylic acid/carboxymethyl cellulose anionic polyelectrolyte (PAA/CMC) and enhanced bioactivity. (2) Methods: Composite cements were prepared by mixing of calcium phosphate powder mixture with hardening liquid containing anionic polyelectrolyte. Phase and microstructural analysis, compressive strength, release of ions and in vitro testing were used for the evaluation of cement properties. (3) Results: The simple possibility to control the setting time of self-setting CXI cements was shown (7–28 min) by the change in P/L ratio or PHYT/F3P reaction time. The wet compressive strength of cements (up to 15 MPa) was close to cancellous bone. The increase in PAA content to 1 wt% caused refinement and change in the morphology of hydroxyapatite particles. Cement pastes had a high resistance to wash-out in a short time after cement mixing. The noncytotoxic character of CX cement extracts was verified. Moreover, PHYT supported the formation of Ca deposits, and the additional synergistic effect of PAA and CMC on enhanced ALP activity was found, along with the strong up-regulation of osteogenic gene expressions for osteopontin, osteocalcin and IGF1 growth factor evaluated by the RT-qPCR analysis in osteogenic αMEM 50% CXI extracts. (4) Conclusions: The fully injectable composite calcium phosphate bicements with anionic polyelectrolyte addition showed good mechanical and physico-chemical properties and enhanced osteogenic bioactivity which is a promising assumption for their application in bone defect regeneration.


2019 ◽  
Vol 33 (8) ◽  
pp. 1094-1104 ◽  
Author(s):  
Guowen Qian ◽  
Xingmei Li ◽  
Fupo He ◽  
Jiandong Ye

Anti-washout calcium phosphate cement (CPC) was prepared by dissolving water-soluble konjac glucomannan (KGM) and κ-carrageenan (KC) blend in the cement liquid. The anti-washout property, setting time, compressive strength and in vitro cytocompatibility of the CPC modified with KGM/KC blend were evaluated. The results indicated that the CPC pastes modified with KGM/KC blend exhibited excellent anti-washout property. The addition of KGM/KC blend shortened the setting time and increased the injectability of CPC. Although the introduction of KGM/KC blend reduced the compressive strength of CPC, the compressive strength still surpassed that of human cancellous bone. The optimal KGM/KC mass ratio was 2:8, with which the modified cement exhibited the most efficient washout resistance and the highest compressive strength. The introduction of KGM/KC blend obviously promoted the proliferation of mouse bone marrow mesenchymal stem cells. This anti-washout CPC modified by KGM/KC blend with excellent in vitro cytocompatibility will have good prospects for application in bone defect repair.


2011 ◽  
Vol 295-297 ◽  
pp. 189-192
Author(s):  
Mao Hong Li ◽  
Shu Xin Qu ◽  
Ning Yao ◽  
Yu Suo Wang ◽  
Ju Mei Zhao ◽  
...  

The long-retention of antibiotics in Calcium Phosphate Cement (CPC) may induce the development of drug resistance. Fast-releasing CPC containing antibiotics (FRCPC) was proposed as a solution to this problem and studied in this work. The FRCPC containing different proportions of soluble component were prepared and characterized. The setting time, compressive strength, degree of the conversion, in vitro antibiotic release and fracture surface morphology of FRCPC were studied. The results showed that the setting time increased, the compressive strength decreased, the in vitro antibiotic release accelerated with increasing fraction of soluble component in FRCPC. The setting time and compressive strength of FRCPC containing 20 wt% soluble components were close to the requirements of clinical applications, and the in vitro release was completed within 7 d. These results mentioned above showed that the FRCPC with suitable proportions of soluble components may prevent the development of drug resistance and may find applications in clinics.


2012 ◽  
Vol 727-728 ◽  
pp. 1187-1192 ◽  
Author(s):  
Rafaela Silveira Vieira ◽  
Wilbur Trajano Guerin Coelho ◽  
Mônica Beatriz Thürmer ◽  
Juliana Machado Fernandes ◽  
Luis Alberto Santos

The calcium phosphate cements (CPCs) based on α-tricalcium phosphate (α-TCP) are highly attractive for use in medicine and odontology, since they have similar chemical and phase composition of mineral phase of bones (calcium deficient hydroxyapatite (CDHA)). However, one of the biggest difficulties for use of this type of cement is its low mechanical strength due to the presence of undesirable phases, such as β-tricalcium phosphate. The route for obtaining α-TCP is at high temperature by solid state reaction, mixing calcium carbonate and calcium pyrophosphate. The aim of this work was to obtain calcium phosphate cements with improved strength, by studying the obtaining of α-TCP at temperatures of 1300, 1400 and 1500°C. The samples were analyzed by crystalline phases, pH, setting time, particle size, in vitro test (Simulated Body Fluid), porosity, density and compressive strength. The results show that the synthesis temperatures influence strongly the phases of powders obtained and the mechanical properties of cement, being unnecessary quenching for obtaining pure α-TCP.


2012 ◽  
Vol 529-530 ◽  
pp. 157-160 ◽  
Author(s):  
Kemal Sariibrahimoglu ◽  
Joop G.C. Wolke ◽  
Sander C.G. Leeuwenburgh ◽  
John A. Jansen

Calcium phosphate cements (CPCs) can be a suitable scaffold material for bone tissue engineering because of their osteoconductivity and perfect fit with the surrounding tissue when injected in situ. However, the main disadvantage of hydroxyapatite (HA) forming CPC is its slow degradation rate, which hinders complete bone regeneration. A new approach is to use hydraulic apatite cement with mainly α/β-tricalciumphosphate (TCP) instead of α-TCP. After hydrolysis the α/β-TCP transforms in a partially non-absorbable HA and a completely resorbable β-TCP phase. Therefore, α-TCP material was thermally treated at several temperatures and times resulting in different α/β-TCP ratios. In this experiment, we developed and evaluated injectable biphasic calcium phosphate cements (BCPC) in vitro. Biphasic α/β-TCP powder was produced by heating α-TCP ranging from 1000-11250°C. Setting time and compressive strength of the CPCs were analyzed after soaking in PBS for 6 weeks. Results demonstrated that the phase composition can be controlled by the sintering temperature. Heat treatment of α-TCP, resulted in 100%, 75% and 25% of α-to β-TCP transformation, respectively. Incorporation of these sintered BCP powder into the cement formulation increased the setting time of the CPC paste. Compressive strength decreased with increasing β-TCP content. In this study, biphasic CPCs were produced and characterized in vitro. This injectable biphasic CPC presented comparable properties to an apatitic CPC.


2017 ◽  
Vol 17 (1) ◽  
pp. 1-9
Author(s):  
L. Medvecky ◽  
R. Stulajterova ◽  
M. Giretova ◽  
M. Faberova

Abstract Prepared powder polyhydroxybutyrate – chitosan - calcium phosphate composite system with 10 wt % of biopolymer component can be utilized as biocement which is characterized by the prolonged setting time and achieves wash out resistance after 5 minutes of setting. The origin powder tetracalcium phosphate/nanomonetite agglomerates were coated with the thin layer of biopolymer which decelerates both the transformation rate of calcium phosphates and hardening process of composites. The porosity of hardened composite was around 62% and the compressive strength (8 MPa) was close to trabecular bone. No cytotoxicity of composite resulted from live/dead staining of osteoblasts cultured on substrates.


2006 ◽  
Vol 309-311 ◽  
pp. 841-844
Author(s):  
S. Chauhan ◽  
M.P. Hofmann ◽  
R.M. Shelton

This study investigated the influence of the addition of various proteins to the liquid phase (albumin, fibrinogen and foetal bovine serum (FBS)) on the mechanical strength and setting time of a brushite forming calcium phosphate cement. Additions of 1wt% protein to the liquid phase led to a deterioration in compressive strength of the set cement by up to 50%. The setting time was not affected by adding albumin and FBS but was increased by 50% with admixtures containing fibrinogen. The conversion of the reactants, β-tricalcium phosphate and monocalcium phosphate, to brushite was found to be unaffected by addition of up to 10wt% proteins.


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