scholarly journals Mechanical Properties of Biomaterials Based on Calcium Phosphates and Bioinert Oxides for Applications in Biomedicine

10.5772/53088 ◽  
2013 ◽  
Author(s):  
Siwar Sakka ◽  
Jamel Bouaziz ◽  
Foued Ben
Keyword(s):  
Mechanical Properties ◽  
Calcium Phosphates

scholarly journals Powder bed selective laser process (sintering/melting) applied to tailored calcium phosphate-based powders

2021 ◽  
Author(s):  
Pedro Navarrete-Segado ◽  
Christine Frances ◽  
Mallorie Tourbin ◽  
Christophe Tenailleau ◽  
Benjamin Duployer ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Calcium Phosphate ◽  
Calcium Phosphates ◽  
Process Window ◽  
X Ray Diffraction ◽  
Powder Bed ◽  
Laser Process ◽  
Whole Process ◽  
Vibrational Spectroscopies ◽  
Complex Parts

This paper focuses on the tailoring of calcium phosphate powders for their use as powder bed selective laser process feedstock. Hydroxyapatite and chlorapatite were used as starting powders for the preparation of different blends through the addition of graphite as a laser absorptance additive. A methodical study was conducted to compare the processing windows of the blends containing different amounts of graphite through the laser patterning of circular samples. It was found that the addition of graphite increases the process window of the powder blends being the powder without additive non processable. Hydroxyapatite showed a clear phase transition (decreased when using higher volumetric energy density) into other calcium phosphate phases while chlorapatite was demonstrated to be thermally stable during the whole process (examined through X-ray diffraction and vibrational spectroscopies). In parallel, the study evaluating the powder blend composed of hydroxyapatite and graphite for the production of solid and complex parts was carried out although it required long printing times. The productivity of the process was improved by modification of printing parameters. Then, a series of solid samples were produced for the analysis of the microstructure and mechanical properties. High interconnected porosity was observed in the samples which could improve the bioactivity of the bioceramic scaffolds. A post-treatment of the parts increased their proportion in the hydroxyapatite phase and their mechanical properties. These results are expected to contribute to the application of powder bed selective laser processing of calcium phosphates powders toward bone tissue engineering.

Influence of Ionic Substitution on the Mechanical Properties of Nanosized Biphasic Calcium Phosphates

InCIEC 2014 ◽  
2015 ◽  
pp. 811-819
Author(s):  
Mohamad Firdaus Abdul Wahid ◽  
Koay Mei Hyie ◽  
Mardziah Che Murad ◽  
N. R. Nik Roselina
Keyword(s):  
Mechanical Properties ◽  
Calcium Phosphates ◽  
Ionic Substitution

Strengthening of Dense Bioceramic Samples Using Bioresorbable Polymers – A Statistical Approach

2009 ◽  
Vol 4 ◽  
pp. 27-39 ◽  
Author(s):  
Sergey V. Dorozhkin ◽  
T. Ajaal
Keyword(s):  
Mechanical Properties ◽  
Experimental Design ◽  
Flexural Strength ◽  
Orthogonal Array ◽  
Calcium Phosphates ◽  
Treatment Temperature ◽  
Taguchi Methods ◽  
Minimal Amount ◽  
Statistical Experimental Design ◽  
Bioresorbable Polymers

Mechanical properties of bioceramics are poor and need to be improved for biomedical applications. In order to do this, bioceramics may be strengthened by bioresorbable polymers. In this study, the mechanical properties of poly(ε-caprolactone), PCL, coated dense bioceramic pellets made of silica-contained calcium phosphates were studied and analyzed using a statistical experimental design in conjunction with Taguchi methods for optimization. The aim of this experimental work was to maximize the pellet flexural strength and minimize the amount of deposited PCL. The most important factors affecting the strengthening of the ceramic pellets were evaluated. Four independent processing variables (a removal technique of an excess polymer solution, concentration of PCL in the solution, a heat treatment temperature and the number of dipping) with three levels of variability were tested using an L9 (34) orthogonal array. A statistical experimental design using the analysis of means and orthogonal array was applied to optimize the responses of these variables. The optimal conditions for achieving the maximal flexural strength of the coated pellets at the minimal amount of the deposited PCL were determined. A high quality dense bioceramic pellets with ~ 10.5 MPa flexural strength and ~ 80 μm thickness (~ 21 mg weight) of the deposited PCL coating were manufactured as a result.

scholarly journals Synthesis, characterization, and thermo-mechanical properties of copper-loaded apatitic calcium phosphates

2013 ◽  
Vol 20 (8) ◽  
pp. 647-660 ◽  
Author(s):  
Marta Galera Martínez ◽  
Doan Pham Minh ◽  
Elsa Weiss-Hortala ◽  
Ange Nzihou ◽  
Patrick Sharrock
Keyword(s):  
Mechanical Properties ◽  
Calcium Phosphates

Recent advances in research on magnesium alloys and magnesium–calcium phosphate composites as biodegradable implant materials

2016 ◽  
Vol 31 (6) ◽  
pp. 878-900 ◽  
Author(s):  
Katarzyna Kuśnierczyk ◽  
Michał Basista
Keyword(s):  
Mechanical Properties ◽  
Metal Matrix Composites ◽  
Magnesium Alloys ◽  
Metal Matrix ◽  
Calcium Phosphates ◽  
Second Phase ◽  
Matrix Composites ◽  
Alloy Matrix ◽  
Biodegradable Implant

Magnesium alloys are modern biocompatible materials suitable for orthopaedic implants due to their biodegradability in biological environment. Many studies indicate that there is a high demand to design magnesium alloys with controllable in vivo corrosion rates and required mechanical properties. A solution to this challenge can be sought in the development of metal matrix composites based on magnesium alloys with addition of relevant alloying elements and bioceramic particles. In this study, the corrosion mechanisms along with corrosion protection methods in magnesium alloys are discussed. The recently developed magnesium alloys for biomedical applications are reviewed. Special attention is given to the newest research results in metal matrix composites composed of magnesium alloy matrix and calcium phosphates, especially hydroxyapatite or tricalcium phosphate, as the second phase with emphasis on the biodegradation behavior, microstructure and mechanical properties in view of potential application of these materials in bone implants.

scholarly journals Bioactive Hydrogels: Design and Characterization of Cellulose-Derived Injectable Composites

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4511
Author(s):  
Andrea Fiorati ◽  
Cristina Linciano ◽  
Camilla Galante ◽  
Maria Grazia Raucci ◽  
Lina Altomare
Keyword(s):  
Mechanical Properties ◽  
Calcium Phosphates ◽  
Low Cost ◽  
Cellulose Nanofibers ◽  
Xrd Analysis ◽  
Bone Tissue Regeneration ◽  
Rheological Characterization ◽  
Inorganic Particles ◽  
Physically Crosslinked ◽  
Injection Force

Cellulose represents a low cost, abundant, and renewable polysaccharide with great versatility; it has a hierarchical structure composed of nanofibers with high aspect ratio (3–4 nm wide, hundreds of μm long). TEMPO-mediated oxidation represents one of the most diffused methods to obtain cellulose nanofibers (CNFs): It is possible to obtain physically crosslinked hydrogels by means of divalent cation addition. The presence of inorganic components, such as calcium phosphates (CaP), can improve not only their mechanical properties but also the bioactivity of the gels. The aim of this work is to design and characterize a TEMPO-oxidized cellulose nanofibers (TOCNFs) injectable hydrogel embedded with inorganic particles, CaP and CaP-GO, for bone tissue regeneration. Inorganic particles act as physical crosslinkers, as proven by rheological characterization, which reported an increase in mechanical properties. The average load value registered in injection tests was in the range of 1.5–4.4 N, far below 30 N, considered a reasonable injection force upper limit. Samples were stable for up to 28 days and both CaP and CaP-GO accelerate mineralization as suggested by SEM and XRD analysis. No cytotoxic effects were shown on SAOS-2 cells cultured with eluates. This work demonstrated that the physicochemical properties of TOCNFs-based dispersions could be enhanced and modulated through the addition of the inorganic phases, maintaining the injectability and bioactivity of the hydrogels.

scholarly journals Development, Characterization and In Vitro Biological Properties of Scaffolds Fabricated From Calcium Phosphate Nanoparticles

2019 ◽  
Vol 20 (7) ◽  
pp. 1790 ◽  
Author(s):  
Lizette Morejón ◽  
José Angel Delgado ◽  
Alexandre Antunes Ribeiro ◽  
Marize Varella de Oliveira ◽  
Eduardo Mendizábal ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mineral Composition ◽  
Cell Attachment ◽  
Sintering Temperature ◽  
Calcium Phosphates ◽  
Total Porosity ◽  
Biological Properties ◽  
Solid Content ◽  
Native Bone

Ceramic materials mimic the mineral composition of native bone and feature osteoconductive properties; they are therefore used to regenerate bone tissue. Much research focuses on increasing the porosity and pore interconnectivity of ceramic scaffolds to increase osteoconductivity, cell migration and cell-cell interaction. We aimed to fabricate biocompatible 3D-scaffolds featuring macro- and microporous calcium phosphates with high pore interconnection. Nanoparticles of hydroxyapatite (HA) and calcium deficient hydroxyapatite (CDHA) were synthesized by wet chemical precipitation. Scaffolds were produced from them by the replication polymeric foam technique. Solid content and sintering temperature were varied. Nanoparticles and scaffolds were characterized regarding morphology, chemical and mineral composition, porosity and mechanical properties. Biocompatibility, cell attachment and distribution were evaluated in vitro with human adipose mesenchymal stem cells. Scaffolds with total porosity of 71%–87%, pores in the range of 280–550 µm and connectivity density up to 43 mm−3 were obtained. Smaller pore sizes were obtained at higher sintering temperature. High solid content resulted in a decrease of total porosity but increased interconnectivity. Scaffolds 50HA/50β-TCP featured superior interconnectivity and mechanical properties. They were bioactive and biocompatible. High HA solid content (40 wt.%) in the HA pure scaffolds was negative for cell viability and proliferation, while in the 50HA/50β-TCP composite scaffolds it resulted more biocompatible.

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