Primary Study of an Injectable In Situ Composite of Collagen/Calcium Phosphate Porous Scaffold for Bone Substitute

2006 ◽  
Vol 309-311 ◽  
pp. 857-860 ◽  
Author(s):  
Q. Yao ◽  
Dong Xiao Li ◽  
K.W. Liu ◽  
Bo Zhang ◽  
H. Li ◽  
...  

This study was to develop an injectable biocompatible and porous calcium phosphate collagen composite cement scaffold by in situ setting. TTCP was prepared as main material of the CPC powder, and the collagen solution was added into the phosphoric acid directly to form the liquid phase. The injectable time (tI), setting time (tS) and setting temperature (TS), along with the PH value were recorded during the setting process. The compressive strength, morphology and porosity were tested. With the increase of collagen, this novel CPC get a tI of 5mins to 8mins, tS of 20mins to 30mins, compressive strength from 1.5MPa to 4MPa, and the porosity from 40% to 60%. This study gave a possibility to form a porous scaffold of collagen/CPC composite with the nature of injectability and setting in situ.

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.


2020 ◽  
Author(s):  
Changtian Gong ◽  
Shuo Fang ◽  
Kezhou Xia ◽  
Jingteng Chen ◽  
Liangyu Guo ◽  
...  

Abstract Incorporating bioactive substances into synthetic bioceramic scaffolds is challenging. In this work, oxygen-carboxymethyl chitosan (O-CMC), a natural biopolymer that is nontoxic, biodegradable and biocompatible, was introduced into magnesium potassium phosphate cement (K-struvite) to enhance its mechanical properties and cytocompatibility. This study aimed to develop O-CMC/magnesium potassium phosphate composite bone cement (OMPC), thereby combining the optimum bioactivity of O-CMC with the extraordinary self-setting properties and mechanical intensity of the K-struvite. Our results indicated that O-CMC incorporation increased the compressive strength and setting time of K-struvite and decreased its porosity and pH value. Furthermore, OMPC scaffolds remarkably improved the proliferation, adhesion and osteogenesis related differentiation of MC3T3-E1 cells. Therefore, O-CMC introduced suitable physicochemical properties to K-struvite and enhanced its cytocompatibility for use in bone regeneration.


Author(s):  
Nuan La Ong Srakaew ◽  
Sirirat Tubsungnoen Rattanachan

Self-setting calcium phosphate cement (CPC) has been used in bone repair and substitution due to their excellent biocompatibility, bioactive as well as simplicity of preparation and use. The inherent brittleness and slow degradation are the major disadvantages for the use of calcium phosphate cements. To improve the degradation for the traditional CPC, the apatite cement formula incorporated with β-tricalcium phosphate (β-TCP) with varying concentration were studied and the effect of the pH value of liquid phase on the properties of this new calcium phosphate cement formula was evaluated. The apatite cements containing β-TCP for 10 and 40 wt.% were mixed into the aqueous solution with different pH values and then aging in absolute humidity at 37°C for 7 days. The setting time and phase analysis of the biphasic calcium phosphate were determined as compared to the apatite cement. For proper medical application, the compressive strength, the phase analysis and the degradation of the CPC samples at pH 7.0 and 7.4 were evaluated after soaking in the simulated body fluid (SBF) at 37°C for 7 days. The results indicated that the properties of the samples such as the setting time, the compressive strength related to the phase analysis of the set cements. The high degradation of the CPC was found in the cement with increasing β-TCP addition due to the phase after setting. Apatite formation with oriented plate-like morphology was also found to be denser on the surface of the biphasic bone cements after soaking in SBF for 7 days. The obtained results indicated that the cement containing β-TCP mixed with the liquid phase at pH 7.4 could be considered as a highly biodegradable and bioactive bone cement, as compared to the traditional CPC.


2006 ◽  
Vol 309-311 ◽  
pp. 861-864 ◽  
Author(s):  
Byung Hyun Lee ◽  
Min Chul Kim ◽  
Kyoung Nam Kim ◽  
Kwang Mahn Kim ◽  
Seong Ho Choi ◽  
...  

In preliminary ageing test, the cement using only calcium phosphate glass as power phase cracked with 1 day in simulated body fluid because of high dissolution rate of the cement. We added 30 wt% of either β-TCP or HA to 70 wt% calcium phosphate glass as powder phase to control the dissolution rate of the cement and performed in vitro ageing test in simulated body fluid by dynamic protocol as well as static protocol to confirm the possibility of controlling. Adding either β-TCP or HA to the cement increases the setting time and decreases the compressive strength. In dynamic assay, the pH of extract is maintained over 7. However, pH decreased to around 5 in static assay. Therefore, weight loss by static protocol continuously increased for 14 days, while weight loss by dynamic protocol almost saturated. In XRD patterns of ageing cements, CaO peaks appeared. CaO peak was maximized most lately in dynamic assay of the cement adding HA and within 7 days, the cement adding HA showed higher weight loss. It is indicated that CaO formed in surface of the cement hinder the dissolution of the cement. In addition, compressive strength increased when the CaO peak was maximized.


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.


2005 ◽  
Vol 284-286 ◽  
pp. 109-112 ◽  
Author(s):  
Byung Hyun Lee ◽  
Min Chul Kim ◽  
Kyoung Nam Kim ◽  
Kwang Mahn Kim ◽  
Seong Ho Choi ◽  
...  

The mixed pastes of binary calcium phosphate glass with Ca/P ratio of 0.6 and distilled water were set after about 4 hr, while never set when calcium phosphate glass with Ca/P lower than 0.5. Their compressive strength was ranged from 16.0 to 23.3 MPa. When Na2HPO4 solution was used instead of distilled water as liquid phase, the setting time became drastically much shorter. As the mole concentration of Na2HPO4 solution increased from 0.25 M to 2 M, setting time was shortened to 35 min from almost 3 hr, but compressive strength decreased from 28.8 MPa to 13.2 MPa. At constant mole concentration, as the mass ratio of a powder to liquid ratio increased, setting time was shortened and maximum compressive strength was measured when a powder/liquid ratio was 2.5. However, no crystallized phases were detected either during setting or after complete setting. The XRD , FT-IR and SEM examinations indicated that calcium phosphate glass dissolved and then glass phase precipitated again. We concluded, therefore, that Na2HPO4 just affected the kinetics of dissolution and precipitation of CPG. The mechanism of hardening has yet to be studied.


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.


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