PREPARATION AND MORPHOLOGY OF POROUS NANOCALCIUM PHOSPHATE/POLY(L-LACTIC ACID) COMPOSITES

2005 ◽  
Vol 04 (04) ◽  
pp. 517-523
Author(s):  
WENJIAN WENG ◽  
YANBO GAO ◽  
LILI PAN ◽  
YANBAO LI ◽  
PIYI DU ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Lactic Acid ◽  
Calcium Phosphate ◽  
Tricalcium Phosphate ◽  
Materials Science ◽  
Calcium Phosphates ◽  
Point Of View ◽  
Thermally Induced Phase Separation ◽  
Thermally Induced ◽  
Highly Porous

Biodegradable porous materials can serve as a scaffold in tissue engineering. In this work, highly porous nano-calcium phosphate (NCP)/poly(L-lactic acid)(PLLA) composites were prepared by a thermally induced phase separation technique. Five calcium phosphates with different biodegradation rate were selected, i.e. amorphous calcium phosphate, α-tricalcium phosphate, β-tricalcium phosphate and biphasic α/β-tricalcium phosphate. The results showed that the NCP particles could be homogenously incorporated into pore walls; the composites had a porosity of ~90%, and a pore size of ~200 μm. From the point of view of materials science, the obtained porous NCP/PLLA composites demonstrate to have a capability of applying in bone tissue engineering.

Preparation of PLLA/HAP/β-TCP Composite Scaffold for Bone Tissue Engineering

2014 ◽  
Vol 513-517 ◽  
pp. 143-146 ◽  
Author(s):  
Xue Jun Wang ◽  
Tao Lou ◽  
Jing Yang ◽  
Zhen Yang ◽  
Kun Peng He
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Lactic Acid ◽  
Phase Separation ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Composite Scaffold ◽  
Thermally Induced Phase Separation ◽  
Composite Scaffolds ◽  
Thermally Induced

In this study, a nanofibrous poly (L-lactic acid) (PLLA) scaffold reinforced by Hydroxyapatite (HAP) and β-tricalcium phosphate (β-TCP) was fabricated using the thermally induced phase separation method. The composite scaffold morphology showed a nanofibrous PLLA matrix and evenly distributed β-TCP/HAP particles. The composite scaffold had interconnective micropores and the pore size ranged 2-10 μm. Introducing β-TCP/HAP particles into PLLA matrix significantly improved the mechanical properties of the composite scaffold. In summary, the new composite scaffolds show a great deal promise for use in bone tissue engineering.

Structure–property relation of porous poly (l-lactic acid) scaffolds fabricated using organic solvent mixtures and controlled cooling rates and its bio-compatibility with human adipose stem cells

2018 ◽  
Vol 33 (4) ◽  
pp. 397-415 ◽  
Author(s):  
Harish Chinnasami ◽  
Jeff Gimble ◽  
Ram V Devireddy
Keyword(s):  
Stem Cells ◽  
Cell Proliferation ◽  
Lactic Acid ◽  
Phase Separation ◽  
Mechanical Strength ◽  
Separation Method ◽  
Thermally Induced Phase Separation ◽  
Cooling Rates ◽  
Thermally Induced ◽  
Pore Sizes

Thermally induced phase separation method was used to make porous three-dimensional poly (l-lactic acid) scaffolds. The effect of imposed thermal profile during freezing of the poly (l-lactic acid) in dioxane solution on the scaffold was characterized by their micro-structure, porosity (%), pore sizes’ distribution, and mechanical strength. The porosity (%) decreased considerably with increasing concentrations of poly (l-lactic acid) in the solution, while a decreasing trend was observed with increasing cooling rates. The mechanical strength increases with increase in poly (l-lactic acid) concentration and also with increase in the cooling rate for both types of solvents. Therefore, mechanical strength was increased by higher cooling rates while the porosity (%) remained relatively consistent. Scaffolds made using higher concentrations of poly (l-lactic acid; 7% and 10% w/v) in solvent showed better mechanical strength which improved relatively with increasing cooling rates (1°C–40°C/min). This phenomenon of enhanced structural integrity with increasing cooling rates was more prominent in scaffolds made from higher initial poly (l-lactic acid) concentrations. Human adipose–derived stem cells were cultured on these scaffold (7% and 10% w/v) prepared by thermally induced phase separation at all cooling rates to measure the cell proliferation efficiency as a function of their micro-structural properties. Mean pore sizes played a crucial role in cell proliferation than percent porosity since all scaffolds were >88% porous. The viability percent of human adipose tissue–derived adult stem cells increased consistently with longer periods of culture. Thus, poly (l-lactic acid) scaffolds prepared by thermally controlled thermally induced phase separation method could be a prime candidate for making ex vivo tissue-engineered grafts for surgical implantation.

scholarly journals Water Uptake in PHBV/Wollastonite Scaffolds: A Kinetics Study

2019 ◽  
Vol 3 (3) ◽  
pp. 74 ◽  
Author(s):  
Ribas ◽  
Montanheiro ◽  
Montagna ◽  
Prado ◽  
Campos ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Phase Separation ◽  
Cell Growth ◽  
Cell Viability ◽  
Water Uptake ◽  
Kinetic Mechanism ◽  
Kinetics Study ◽  
Biological Applications ◽  
Thermally Induced Phase Separation ◽  
Thermally Induced

Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) is a widely studied polymer and it has been found that porous PHBV materials are suitable for substrates for cell cultures. A crucial factor for scaffolds designed for tissue engineering is the water uptake. This property influences the transport of water and nutrients into the scaffold, which promotes cell growth. PHBV has significant hydrophobicity, which can harm the production of cells. Thus, the addition of α-wollastonite (WOL) can modify the PHBV scaffold’s water uptake. To our knowledge, a kinetics study of water uptake of α-wollastonite phase powder and the PHBV matrix has not been reported. In this work, PHBV and WOL, (PHBV/WOL) films were produced with 0, 5, 10, and 20 wt % of WOL. Films were characterized, and the best concentrations were chosen to produce PHBV/WOL scaffolds. The addition of WOL in concentrations up to 10 wt % increased the cell viability of the films. MTT analysis showed that PHBV/5%WOL and PHBV/10%WOL obtained cell viability of 80% and 98%, respectively. Therefore, scaffolds with 0, 5 and 10 wt % of WOL were fabricated by thermally induced phase separation (TIPS). Scaffolds were characterized with respect to morphology and water uptake in assay for 65 days. The scaffold with 10 wt % of WOL absorbed 44.1% more water than neat PHBV scaffold, and also presented a different kinetic mechanism when compared to other samples. Accordingly, PHBV/WOL scaffolds were shown to be potential candidates for biological applications.

scholarly journals Poly(d,l-Lactic acid) Composite Foams Containing Phosphate Glass Particles Produced via Solid-State Foaming Using CO2 for Bone Tissue Engineering Applications

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 231 ◽  
Author(s):  
Maziar Shah Mohammadi ◽  
Ehsan Rezabeigi ◽  
Jason Bertram ◽  
Benedetto Marelli ◽  
Richard Gendron ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Lactic Acid ◽  
Solid State ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Melt Compounding ◽  
Composite Foams ◽  
Biodegradable Poly ◽  
Gaseous Carbon Dioxide ◽  
Highly Porous

This study reports on the production and characterization of highly porous (up to 91%) composite foams for potential bone tissue engineering (BTE) applications. A calcium phosphate-based glass particulate (PGP) filler of the formulation 50P2O5-40CaO-10TiO2 mol.%, was incorporated into biodegradable poly(d,l-lactic acid) (PDLLA) at 5, 10, 20, and 30 vol.%. The composites were fabricated by melt compounding (extrusion) and compression molding, and converted into porous structures through solid-state foaming (SSF) using high-pressure gaseous carbon dioxide. The morphological and mechanical properties of neat PDLLA and composites in both nonporous and porous states were examined. Scanning electron microscopy micrographs showed that the PGPs were well dispersed throughout the matrices. The highly porous composite systems exhibited improved compressive strength and Young’s modulus (up to >2-fold) and well-interconnected macropores (up to ~78% open pores at 30 vol.% PGP) compared to those of the neat PDLLA foam. The pore size of the composite foams decreased with increasing PGPs content from an average of 920 µm for neat PDLLA foam to 190 µm for PDLLA-30PGP. Furthermore, the experimental data was in line with the Gibson and Ashby model, and effective microstructural changes were confirmed to occur upon 30 vol.% PGP incorporation. Interestingly, the SSF technique allowed for a high incorporation of bioactive particles (up to 30 vol.%—equivalent to ~46 wt.%) while maintaining the morphological and mechanical criteria required for BTE scaffolds. Based on the results, the SSF technique can offer more advantages and flexibility for designing composite foams with tunable characteristics compared to other methods used for the fabrication of BTE scaffolds.

scholarly journals Calcium phosphate materials in bone tissue engineering

2014 ◽  
Vol 61 (2) ◽  
pp. 93-101 ◽  
Author(s):  
Vukoman Jokanovic ◽  
Bozana Colovic ◽  
Marija Zivkovic-Sandic ◽  
Violeta Petrovic ◽  
Slavoljub Zivkovic
Keyword(s):  
Tissue Engineering ◽  
Calcium Phosphate ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
21St Century ◽  
Bone Disease ◽  
Calcium Phosphates ◽  
Current Paper ◽  
National Book ◽  
Young Researchers

Calcium phosphates, together with polymers, are most commonly used materials in bone engineering since their composition is similar to bone. They are used to fulfill various defects caused by injury or bone disease, as well as for the preparation of endodontic mixtures. Because of their great importance in dentistry, these materials are given special attention in the current paper. This paper is a part of the monograph entitled ?Nanomedicine, the Greatest Challenge of the 21st Century?, which attracted great interest of technical and professional communities in different areas of medicine. Also for the last two years this book is promoted by the Student Cultural Centre as the only national book chosen in the narrowest election. That fact is very important for young researchers who study tissue engineering, endodontics and implantology.

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