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

• Cijun Shuai ^[1] ; Yi Nie ^[1] ; Chengde Gao ^[1] ; Haibo Lu ^[1] ; Huanlong Hu ^[1] ; Xuejun Wen ^[2] ; Shuping Peng ^[3]
  1. [1] Central South University

     Central South University

     China

     
  2. [2] Medical University of South Carolina

     Medical University of South Carolina

     Estados Unidos

     
  3. [3] Central South University Cancer Research Institute

  Mostrar afiliaciones +
• Localización: Electronic Journal of Biotechnology, ISSN-e 0717-3458, Vol. 15, Nº. 6, 2012, págs. 4-4
• Idioma: inglés
• Enlaces
  • Texto completo
• Resumen

  • 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.