Bellucci Devis, Cannillo Valeria, Sola Antonella
Dipartimento di Ingegneria dei Materiali e dell'Ambiente, Università degli Studi di Modena e Reggio Emilia, Via Vignolese 905, 41125 Modena, Italy.
Materials (Basel). 2011 Jan 28;4(2):339-354. doi: 10.3390/ma4020339.
Hydroxyapatite (HA) has been widely investigated as scaffolding material for bone tissue engineering, mainly for its excellent biocompatibility. Presently, there is an increasing interest in the composites of hydroxyapatite with bioactive glasses, with the aim to obtain systems with improved bioactivity or mechanical properties. Moreover, modifying the ratio between bioactive glass and hydroxyapatite results in the possibility of controlling the reaction rate of the composite scaffold in the human body. However, high temperature treatments are usually required in order to sinter HA-based composites, causing the bioactive glass to crystallize into a glass-ceramic, with possible negative effects on its bioactivity. In the present research work, a glass composition belonging to the Na₂O-CaO-P₂O₅-SiO₂ system, with a reduced tendency to crystallize, is applied to realize HA-based composites. The novel samples can be sintered at a relative low temperature (750 °C) compared to the widely studied HA/45S5 Bioglass composites. This fact greatly helps to preserve the amorphous nature of the glass, with excellent effects in terms of bioactivity, according to in vitro tests. As a first application, the obtained composites are also tested to realize highly porous scaffolds by means of the standard burning out method.
羟基磷灰石（HA）作为骨组织工程的支架材料已被广泛研究，主要因其具有优异的生物相容性。目前，人们对羟基磷灰石与生物活性玻璃的复合材料越来越感兴趣，目的是获得具有改善的生物活性或机械性能的体系。此外，改变生物活性玻璃与羟基磷灰石之间的比例会导致控制复合支架在人体中的反应速率成为可能。然而，为了烧结基于HA的复合材料通常需要高温处理，这会使生物活性玻璃结晶成玻璃陶瓷，可能对其生物活性产生负面影响。在本研究工作中，应用了一种属于Na₂O-CaO-P₂O₅-SiO₂体系且结晶倾向降低的玻璃组合物来制备基于HA的复合材料。与广泛研究的HA/45S5生物活性玻璃复合材料相比，新型样品可以在相对较低的温度（750℃）下烧结。根据体外测试，这一事实极大地有助于保持玻璃的非晶态性质，在生物活性方面具有优异的效果。作为首次应用，还通过标准的烧失法对获得的复合材料进行测试以制备高度多孔的支架。
