Functionalisation of periodic cellular bioactive glass scaffolds via the tailored design of compositional gradients

三维、高度多孔和细胞生物活性玻璃支架对于原位（通过直接植入患者体内）或异位（通过组织工程）的组织再生都是令人感兴趣的。由于生物活性玻璃的显著结晶倾向（其抑制致密支架支柱的烧结），这些构建体经常遭受差的机械稳定性，例如低于IMPa的压缩强度。这使得机械增强成为必要，这通常通过与聚合物组合来实现。在这里，一个双重的方法是解决，它结合了新的支架几何形状与无机功能化通过使用不同的玻璃类型（例如硅酸盐和磷酸盐），以获得组成梯度。在玻璃层的烧结过程中的扩散过程的影响进行了分析，以调查这种梯度的形成。此外，梯度对降解和离子释放以及支架机械稳定性的影响将被表征。新的支架几何形状将通过立体光刻技术制造聚合物模板，然后通过复制方法合成支架。除了将CAD模型与支架的微型计算机断层扫描直接比较以研究模板精度外，对真实的结构模型的有限元模拟将有助于理解支架的力学行为。

Three-dimensional, highly porous and cellular bioactive glass scaffolds are of interest for tissue regeneration both in situ (by direct implantation into the patient) or ex situ (via tissue engineering). Owing to the pronounced crystallisation tendency of bioactive glasses, which inhibits the sintering of dense scaffold struts, these constructs often suffer from poor mechanical stability, e.g. compressive strengths below 1 MPa. This makes mechanical reinforcement necessary, which typically is achieved by combination with polymers. Here, a two-fold approach is addressed, which combines new scaffold geometries with inorganic functionalisation by the use of different glass types (e.g. silicate and phosphate) to obtain compositional gradients. The influence of diffusion processes during the sintering of glass layers is analysed to investigate the formation of such gradients. In addition, the influence of gradients on both degradation and ion release but also on scaffold mechanical stability will be characterised. New scaffold geometries will be obtained by additive manufacturing ofpolymer templates via stereo lithography, followed by scaffold synthesis via the replica approach. Besides the direct comparison of CAD models with scaffold micro-computer tomography scans to investigate templating precision, FEM simulations on real structuremodels will help to understand scaffold mechanical behaviour.