The Influence of Hydroxyapatite Particles on In Vitro Degradation Behavior of Poly ε-Caprolactone-Based Composite Scaffolds
The Influence of Hydroxyapatite Particles on In Vitro Degradation Behavior of Poly ε-Caprolactone-Based Composite Scaffolds
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DOI：
10.1089/ten.tea.2008.0543
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发表时间：
2009-11-01
影响因子：
4.1
通讯作者：
Ambrosio, Luigi
中科院分区：
文献类型：
--
作者：
Guarino, Vincenzo;Taddei, Paola;Ambrosio, Luigi
具有缓慢降解动力学的复合支架的设计要求评估降解的时间过程以预测长期的体外行为。研究了羟基磷灰石（HA）颗粒对聚ε-己内酯复合支架材料水解降解的影响。通过研究碱性介质中的加速降解机制，可以分析不同时间的可比降解情况。通过扫描电子显微镜图像分析支持的形态学的准确定性和定量研究表明，只有一个可以忽略不计的结构孔隙率的影响，归因于添加微米HA作为填料。此外，通过比较的拉曼光谱与热分析（热重分析和差示扫描量热法）的HA的复合材料的降解机制的作用被定义，通过分别量化的HA颗粒在本体和表面上的贡献，对骨形成作为一个功能的孔形态，以及物理和化学性质的聚合物基质中诱导的修改。事实上，HA颗粒改变了聚ε-己内酯结晶度，引起了聚合物基质的“屏蔽”效应。同时，随着HA含量的增加，支架材料的孔径略有减小，支架材料的有效亲水性得到改善，这也影响了支架材料的降解速度。最后，已经证明HA的存在增强了支架的生物活性和人成骨细胞的反应，说明生物活性信号对促进表面矿化以及因此对细胞-材料相互作用的积极作用。
The design of composite scaffolds with slow degradation kinetics imposes the assessment of the time-course of degradation to predict the long-term in vitro behavior. In this work, the effect of hydroxyapatite ( HA) particles on the hydrolytic degradation of poly epsilon-caprolactone composite scaffold was investigated. The study of accelerated degradation mechanisms in alkaline medium enabled analysing comparable degradation profiles at different times. The accurate qualitative and quantitative study of morphology by scanning electron microscopy supported by image analysis demonstrated only a negligible effect on the structural porosity, to be ascribed to the addition of micrometric HA as a filler. Moreover, by comparing the Raman spectra with thermal analysis (thermogravimetry and differential scanning calorimetry) the role of HA on the composite degradation mechanism was defined, by separately quantifying the contribution of HA particles in the bulk and on the surface, on the bone formation as a function of modifications induced in the pore morphology, as well as physical and chemical properties of the polymer matrix. Indeed, HA particles alter the poly epsilon-caprolactone crystallinity inducing a "shielding'' effect of the polymer matrix. Meanwhile, the slight reduction of pore size as a function of the increasing HA content and the improvement of the effective hydrophilicity of the scaffolds also influence the degradation by faster mechanisms. Finally, it has been proven that the presence of HA enhances the scaffold bioactivity and human osteoblast cell response, remarking the active role of bioactive signals on the promotion of the surface mineralization and, as a consequence, on the cell-material interaction.