Poly (l-lactide acid) improves complete nano-hydroxyapatite bone scaffolds through the microstructure rearrangement



Document title: Poly (l-lactide acid) improves complete nano-hydroxyapatite bone scaffolds through the microstructure rearrangement
Journal: Electronic journal of biotechnology
Database: PERIÓDICA
System number: 000357873
ISSN: 0717-3458
Authors: 1
1
1
1
1
2
3
Institutions: 1Central South University, State Key Laboratory of High Performance Complex Manufacturing, Changsha. China
2Medical University of South Carolina, Department of Regenerative Medicine & Cell Biology, Charleston, Carolina del Sur. Estados Unidos de América
3Central South University, Cancer Research Institute, Changsha. China
Year:
Volumen: 15
Number: 6
Country: Chile
Language: Inglés
Document type: Artículo
Approach: Experimental, aplicado
English abstract Cracks often occur when nano-hydroxyapatite bone scaffolds are fabricated with selective laser sintering, which affect the performance of scaffolds. In this study, a small amount of poly (l-lactide acid) (PLLA) was added into nano-hydroxyapatite (nano-HAP) powder by mechanical blending in order to improve the sintering properties. The nano-HAP powder combined with 1wt % PLLA was sintered under different laser power (5W, 7.5W, 10W, 12.5W, 15W and 20W). The fabricated scaffolds were characterized using Scanning Electron Microscope (SEM), X-ray Diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and Micro Hardness Tester. The results showed that nano-HAP particles grew up quickly with the laser power increasing, and there were many strip-like cracks on the surface of sintering zone. The cracks gradually reduced until disappeared when the laser power increased to 15W, together with a great improvement of density. Large pores were observed on the specimen when the laser power further increases, accompanied with the decomposition of HAP into β-tricalcium phosphate (β-TCP) and tetracalcium phosphate (TTCP). And the optimum parameters were eventually obtained with laser power of 15W, scanning speed of 1000 mm/min, powder bed temperature of 150ºC, laser spot diameter of 2 mm and layer thickness of 0.2 mm. We summarized that the molten PLLA enhanced the particle rearrangement of nano-HAP by capillary force and may absorb thermal stress in laser sintering process, while PLLA would be oxidized gradually until completely excluded from the sintered nano-HAP scaffolds, which was confirmed by FTIR analysis. This study provides a novel method to improve the sintering properties of nano-HAP with no adverse effects which would be used in the application of bone tissue engineering potentially
Disciplines: Biología
Keyword: Biotecnología,
Biomateriales,
Hidroxiapatita,
Microestructuras,
Dureza,
Propiedades térmicas
Keyword: Biology,
Biotechnology,
Biomaterials,
Hydroxyapatite,
Microstructures,
Hardness,
Thermal properties
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