scholarly journals Studies on Poly(propylene fumarate-co-caprolactone diol) Thermoset Composites towards the Development of Biodegradable Bone Fixation Devices

2009 ◽  
Vol 2009 ◽  
pp. 1-10 ◽  
Author(s):  
M. Jayabalan
Keyword(s):  
Compressive Strength ◽  
Setting Time ◽  
Hydrolytic Degradation ◽  
Thermoset Composites ◽  
Ringer’S Solution ◽  
Compression Properties ◽  
Reinforced Composite ◽  
Link Density ◽  
Poly Propylene

The effect of reinforcement in the cross-linked poly(propylene fumarate-co-caprolactone diol) thermoset composites based on Kevlar fibres and hydroxyapatite was studied. Cross-linked poly(propylene fumarate-co-caprolactone diol) was also studied without any reinforcement for comparison. The reinforcing fibre acts as a barrier for the curing reaction leading to longer setting time and lesser cross-link density. The fibre and HA reinforced composites have almost the same compressive strength. Nonreinforced material undergoes greater degree of swelling. Among the reinforced materials, the hydroxyapatite reinforced composite has a much higher swelling percentage than the fibre reinforced one. The studies on in vitro degradation of the cured materials reveal hydrolytic degradation in Ringer's solution and PBS medium during aging. All the three materials are found to swell initially in Ringer's solution and PBS medium during aging and then undergo gradual degradation. Compression properties of these cross-linked composites increase with aging; HA reinforced composite has the highest compressive strength and compressive modulus, whereas the aged fibre-reinforced composite has the least compressive strength and modulus.

scholarly journals Brushite cement containing gelatin: evaluation of mechanical strength and in vitro degradation

Cerâmica ◽  
2019 ◽  
Vol 65 (374) ◽  
pp. 261-266 ◽  
Author(s):  
L. P. Silva ◽  
M. D. P. Ribeiro ◽  
E. S. Trichês ◽  
M. Motisuke
Keyword(s):  
Mechanical Properties ◽  
Weight Loss ◽  
Compressive Strength ◽  
Solid Phase ◽  
Setting Time ◽  
Biological Properties ◽  
Solubility In Water ◽  
Ringer’S Solution ◽  
Weight Loss Data

Abstract Calcium phosphate cements (CPCs) are potential materials for repairing bone defects, mainly due to their excellent biocompatibility and osteoconductivity. Nevertheless, their low mechanical properties limit their usage in clinical applications. The gelatin addition may improve the mechanical and biological properties of CPCs, but their solubility in water may increase the porosity of the cement during degradation. Thus, the aim of this work was to investigate the influence of gelatin on the setting time, compressive strength and degradation rate of a brushite cement. CPCs were prepared with the addition of 0, 5, 10 and 20 wt% of gelatin powder in the solid phase of the cement. The results indicated that the setting time increased with gelatin. Furthermore, cement with 20 wt% of gelatin had an initial compressive strength of 14.1±1.8 MPa while cement without gelatin had 4.5±1.2 MPa. The weight loss, morphology and compressive strength were evaluated after degradation in Ringer’s solution. According to the weight loss data, gelatin was eliminated of samples during degradation. It was concluded that the presence of gelatin improved CPCs mechanical properties; however, as degradation in Ringer’s solution evolved, cement compressive strength decreased due to gelatin dissolution and, consequently, an increase in sample porosity.

scholarly journals Injectable Enzymatically Hardened Calcium Phosphate Biocement

2020 ◽  
Vol 11 (4) ◽  
pp. 74
Author(s):  
Lubomir Medvecky ◽  
Radoslava Štulajterová ◽  
Maria Giretova ◽  
Lenka Luptakova ◽  
Tibor Sopčák
Keyword(s):  
Compressive Strength ◽  
Calcium Phosphate ◽  
Setting Time ◽  
Microstructural Analysis ◽  
Chemical Properties ◽  
Gene Expressions ◽  
Cement Pastes ◽  
Anionic Polyelectrolyte ◽  
Simple Possibility

(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.

Improving the anti-washout property of calcium phosphate cement by introducing konjac glucomannan/κ-carrageenan blend

2019 ◽  
Vol 33 (8) ◽  
pp. 1094-1104 ◽  
Author(s):  
Guowen Qian ◽  
Xingmei Li ◽  
Fupo He ◽  
Jiandong Ye
Keyword(s):  
Compressive Strength ◽  
Calcium Phosphate ◽  
Calcium Phosphate Cement ◽  
Setting Time ◽  
Konjac Glucomannan ◽  
Water Soluble ◽  
Mouse Bone Marrow ◽  
Human Cancellous Bone ◽  
Marrow Mesenchymal Stem Cells

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.

Study on Fast-Releasing Calcium Phosphate Cement for Accelerating the Release of Antibiotic

2011 ◽  
Vol 295-297 ◽  
pp. 189-192
Author(s):  
Mao Hong Li ◽  
Shu Xin Qu ◽  
Ning Yao ◽  
Yu Suo Wang ◽  
Ju Mei Zhao ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Compressive Strength ◽  
Calcium Phosphate ◽  
Calcium Phosphate Cement ◽  
Setting Time ◽  
Clinical Applications ◽  
Soluble Component ◽  
Antibiotic Release ◽  
Soluble Components

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.

scholarly journals The comparative evaluation of various additives on setting time and compressive strength of MTA Plus: An in vitro study

Endodontology ◽  
2021 ◽  
Vol 33 (1) ◽  
pp. 36
Author(s):  
Mahima Tilakchand ◽  
Priyanka Pandey ◽  
Praveen Shetty ◽  
Balaram Naik ◽  
Shruti Shetti
Keyword(s):  
Compressive Strength ◽  
Comparative Evaluation ◽  
Setting Time ◽  
In Vitro Study ◽  
Vitro Study

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 ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Silicon Nitride ◽  
Calcium Phosphate ◽  
Tricalcium Phosphate ◽  
Setting Time ◽  
Controlled Drug Release ◽  
Tetracalcium Phosphate ◽  
Composite Cement ◽  
Highly Porous

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.

Characterization of α/β-TCP Based Injectable Calcium Phosphate Cement as a Potential Bone Substitute

2012 ◽  
Vol 529-530 ◽  
pp. 157-160 ◽  
Author(s):  
Kemal Sariibrahimoglu ◽  
Joop G.C. Wolke ◽  
Sander C.G. Leeuwenburgh ◽  
John A. Jansen
Keyword(s):  
Compressive Strength ◽  
Calcium Phosphate ◽  
Setting Time ◽  
Surrounding Tissue ◽  
Calcium Phosphate Cements ◽  
Apatite Cement ◽  
Tcp Phase

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.

scholarly journals Effect of Calcium Acetate Content on Apatite-Forming Ability and Mechanical Property of PMMA Bone Cement Modified with Quaternary Ammonium

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4998
Author(s):  
Haiyang Wang ◽  
Toshinari Maeda ◽  
Toshiki Miyazaki
Keyword(s):  
Compressive Strength ◽  
Bone Cement ◽  
Setting Time ◽  
Antibacterial Properties ◽  
Calcium Acetate ◽  
The Body ◽  
Apatite Formation ◽  
Pmma Bone Cement ◽  
Pmma Cement

Polymethyl methacrylate (PMMA)-based bone cement is a popular biomaterial used for fixation of artificial joints. A next-generation bone cement having bone-bonding ability, i.e., bioactivity and antibacterial property is desired. We previously revealed that PMMA cement added with 2-(tert-butylamino)ethyl methacrylate, γ-methacryloxypropyltrimethoxysilane and calcium acetate showed in vitro bioactivity and antibacterial activity. This cement contains calcium acetate at 20% of the powder component. Lower content of the calcium acetate is preferable, because the release of a lot of calcium salt may degrade mechanical properties in the body environment. In the present study, we investigate the effects of calcium acetate content on the setting property and mechanical strength of the cement and apatite formation in simulated body fluid (SBF). The setting time increased and the compressive strength decreased with an increase in calcium acetate content. Although the compressive strength decreased after immersion in SBF for 7 d, all the cements still satisfied the requirements of ISO5833. Apatite was formed in SBF within 7 d on the samples where the calcium acetate content was 5% or more. Therefore, it was found that PMMA cement having antibacterial properties and bioactivity can be obtained even if the amount of the calcium acetate is reduced to 5%.

DURALCAN F3S.xxS

Alloy Digest ◽  
1994 ◽  
Vol 43 (10) ◽  
Keyword(s):  
Fracture Toughness ◽  
Silicon Carbide ◽  
Compressive Strength ◽  
Aluminum Alloy ◽  
High Temperature ◽  
Base Alloy ◽  
Alloy Matrix ◽  
Reinforced Composite ◽  
Temperature Performance ◽  
Aluminum Alloy Matrix

Abstract Duralcan F3S.xxS is a heat treatable aluminum alloy-matrix gravity composite. The base alloy is similar to Aluminum 359 (Alloy Digest Al-188, July 1969); the discontinuously reinforced composite is silicon carbide. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and compressive strength as well as fracture toughness and fatigue. It also includes information on high temperature performance. Filing Code: AL-329. Producer or source: Alcan Aluminum Corporation.

scholarly journals Cobalt-doped bioceramic scaffolds fabricated by 3D printing show enhanced osteogenic and angiogenic properties for bone repair

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Jungang Li ◽  
Chaoqian Zhao ◽  
Chun Liu ◽  
Zhenyu Wang ◽  
Zeming Ling ◽  
...  
Keyword(s):  
Compressive Strength ◽  
3D Printing ◽  
Bone Regeneration ◽  
Doping Concentration ◽  
Artificial Bone ◽  
Bone Defect Repair ◽  
Co Doping ◽  
Defect Repair ◽  
Co Doped

Abstract Background The bone regeneration of artificial bone grafts is still in need of a breakthrough to improve the processes of bone defect repair. Artificial bone grafts should be modified to enable angiogenesis and thus improve osteogenesis. We have previously revealed that crystalline Ca10Li(PO4)7 (CLP) possesses higher compressive strength and better biocompatibility than that of pure beta-tricalcium phosphate (β-TCP). In this work, we explored the possibility of cobalt (Co), known for mimicking hypoxia, doped into CLP to promote osteogenesis and angiogenesis. Methods We designed and manufactured porous scaffolds by doping CLP with various concentrations of Co (0, 0.1, 0.25, 0.5, and 1 mol%) and using 3D printing techniques. The crystal phase, surface morphology, compressive strength, in vitro degradation, and mineralization properties of Co-doped and -undoped CLP scaffolds were investigated. Next, we investigated the biocompatibility and effects of Co-doped and -undoped samples on osteogenic and angiogenic properties in vitro and on bone regeneration in rat cranium defects. Results With increasing Co-doping level, the compressive strength of Co-doped CLP scaffolds decreased in comparison with that of undoped CLP scaffolds, especially when the Co-doping concentration increased to 1 mol%. Co-doped CLP scaffolds possessed excellent degradation properties compared with those of undoped CLP scaffolds. The (0.1, 0.25, 0.5 mol%) Co-doped CLP scaffolds had mineralization properties similar to those of undoped CLP scaffolds, whereas the 1 mol% Co-doped CLP scaffolds shown no mineralization changes. Furthermore, compared with undoped scaffolds, Co-doped CLP scaffolds possessed excellent biocompatibility and prominent osteogenic and angiogenic properties in vitro, notably when the doping concentration was 0.25 mol%. After 8 weeks of implantation, 0.25 mol% Co-doped scaffolds had markedly enhanced bone regeneration at the defect site compared with that of the undoped scaffold. Conclusion In summary, CLP doped with 0.25 mol% Co2+ ions is a prospective method to enhance osteogenic and angiogenic properties, thus promoting bone regeneration in bone defect repair.

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