3B's Research Group - Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark, 4806-909, Taipas, Guimarães, Portugal.
Mater Sci Eng C Mater Biol Appl. 2013 Oct;33(7):4480-3. doi: 10.1016/j.msec.2013.06.044. Epub 2013 Jul 4.
Fundamental aspects of biomineralization may be important in order to understand and improve calcification onto the surface of biomaterials. The biomineralization process is mainly followed in vitro by assessing the evolution of the apatite layer that is formed upon immersion of the material in Simulated Body Fluid (SBF). In this work we propose an innovative methodology to monitor apatite deposition by looking at the evolution of the mechanical/viscoelastic properties of the sample while immersed in SBF, using non-conventional dynamic mechanical analysis (DMA) performed under distinct displacement amplitudes (d). The biomimetic biomineralization process in composite membranes of chitosan (CTS) with Bioglass® (BG) was followed by measuring the change of the storage modulus, E', and the loss factor, tan δ, at 37 °C and in SBF, both online (d=10 μm and d=30 μm) and offline (d=0 μm). The online experiments revealed that the E' decreased continuously up in the first hours of immersion in SBF that should be related to the dissolution of BG particles. After that, an increase of the stiffness was verified due to the apatite deposition. SEM/EDS observations upon 24h of immersion in SBF showed higher development of apatite deposition with increasing displacement amplitude.
为了理解和改善生物材料表面的钙化，生物矿化的基本方面可能很重要。生物矿化过程主要通过评估材料浸入模拟体液 (SBF) 后形成的磷灰石层的演变来体外进行。在这项工作中，我们提出了一种创新的方法，通过在 SBF 中浸入时观察样品的机械/粘弹性特性的演变来监测磷灰石的沉积，使用在不同位移幅度 (d) 下进行的非传统动态力学分析 (DMA)。通过测量在 37°C 和 SBF 下的存储模量 E'和损耗因子 tan δ 的变化，来跟踪壳聚糖 (CTS) 与 Bioglass® (BG) 的复合膜中的仿生矿化过程，在线（d=10 μm 和 d=30 μm）和离线（d=0 μm）。在线实验表明，在浸入 SBF 的最初几个小时内，E'持续下降，这应该与 BG 颗粒的溶解有关。之后，由于磷灰石的沉积，刚度增加。浸入 SBF 24 小时后的 SEM/EDS 观察显示，随着位移幅度的增加，磷灰石的沉积得到了更好的发展。
