Hong Zhongkui, Reis Rui L, Mano João F
University of Minho, 3B's Research Group - Biomaterials, Biodegradables and Biomimetics, Department of Polymer Engineering, Campus de Gualtar, 4710-057 Braga, Portugal.
Acta Biomater. 2008 Sep;4(5):1297-306. doi: 10.1016/j.actbio.2008.03.007. Epub 2008 Apr 1.
Porous nanocomposite scaffolds of poly(l-lactic acid) (PLLA) containing different quantities of bioactive glass ceramic (BGC) nanoparticles (SiO(2):CaO:P(2)O(5) approximately 55:40:5 (mol)) were prepared by a thermally induced phase-separation method. Dioxane was used as the solvent for PLLA. Introduction of less than 20wt.% of BGC nanoparticles did not remarkably affect the porosity of PLLA foam. However, as the BGC content increased to 30wt.%, the porosity of the composite was observed to decrease rapidly. The compressive modulus of the scaffolds increased from 5.5 to 8.0MPa, while the compressive strength increased from 0.28 to 0.35MPa as the BGC content increased from 0 to 30wt.%. The in vitro bioactivity and biodegradability of nanocomposites were investigated by incubation in simulated body fluid (SBF) and phosphate-buffered saline, respectively. Scanning electron microscopy, energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy and X-ray diffraction were employed to monitor the surface variation of neat PLLA and PLLA/BGC porous scaffolds during incubation. PLLA/(20wt.%)BGC composite exhibited the best mineralization property in SBF, while the PLLA/(10wt.%)BGC composite showed the highest water absorption ability.
采用热致相分离法制备了含有不同含量生物活性玻璃陶瓷(BGC)纳米颗粒(SiO₂:CaO:P₂O₅ 约为55:40:5(摩尔比))的聚(L-乳酸)(PLLA)多孔纳米复合支架。二氧六环用作PLLA的溶剂。引入少于20wt.%的BGC纳米颗粒对PLLA泡沫的孔隙率没有显著影响。然而,当BGC含量增加到30wt.%时,观察到复合材料的孔隙率迅速降低。随着BGC含量从0增加到30wt.%,支架的压缩模量从5.5MPa增加到8.0MPa,而压缩强度从0.28MPa增加到0.35MPa。分别通过在模拟体液(SBF)和磷酸盐缓冲盐水中孵育来研究纳米复合材料的体外生物活性和生物降解性。采用扫描电子显微镜、能量色散X射线光谱、傅里叶变换红外光谱和X射线衍射来监测纯PLLA和PLLA/BGC多孔支架在孵育过程中的表面变化。PLLA/(20wt.%)BGC复合材料在SBF中表现出最佳的矿化性能,而PLLA/(10wt.%)BGC复合材料表现出最高的吸水能力。