Characterisation of ceramic bone graft environments for optimised angiogenesis

多年来，由于磷酸钙植入物与人体硬组织的矿物成分相似，因此在骨骼修复中使用磷酸钙植入物已经引起了极大的兴趣。然而，骨移植替代物的有效性受到其支持组织生长和促进血管生成的能力的强烈影响。Gariboldi等人之前在3D打印受控羟基磷灰石结构作为模型基质来研究血管生成方面所做的工作已经成功地建立了技术，不仅与这种基质的3D打印有关，而且还与培养适当的细胞组合以产生排列的微血管有关。这一结果为进一步研究领域提供了大量新的思路和可能性。表面粗糙度和孔隙结构的控制是近年来生物材料和生物陶瓷领域的一个非常热门的话题，因为它对蛋白质吸附（如等离子体）的影响。初步研究将评估蛋白质吸附的性质及其释放动力学。这项工作将继续考虑这如何影响破骨细胞重塑和成骨细胞介导的骨沉积。虽然单一培养在过去经常被使用，但生理相关细胞的共同培养的重要性越来越被认为是一种提供更好的理解骨修复的潜在机制和过程的方法。使用高度可控的模型2.5D环境，可以更详细地研究支架结构和表面粗糙度对血管生成和骨诱导骨移植替代品的影响。此外，我打算将在2.5D中所做的发现转化为更具有挑战性的受控3D环境生产方面，作为该项目的一部分。在这个项目的过程中，我试图发展我在活细胞成像方面的专业知识，以了解细胞与细胞的相互作用。此外，我将发展研究小组中现成的技能和知识，并探索如何将x射线微断层扫描（microCT）与使用适当的造影剂相结合。这些包括用于评估血管生成的抗体偶联物，更广泛地说，提供有关蛋白质吸附在骨修复中的作用的信息。研究的结果将是提高对骨移植替代品上蛋白质吸附对骨修复的影响的理解，并进一步了解支架结构和表面形貌在指导细胞行为中的作用。

There has been significant interest over a number of years in the use of calcium phosphate implants for skeletal repair due to their similarity in composition to the mineral component of the hard tissues in the body. However, the efficacy of bone graft substitutes is strongly influenced by their ability to support tissue in-growth and encourage angiogenesis. Previous work done by Gariboldi et al. on the 3D printing of controlled hydroxyapatite architectures as model substrates to study angiogenesis has resulted in the successful establishment techniques not only relating to the 3D printing of such substrates but also to culture the appropriate combination of cells to produce aligned micro-vessels. This result gives rise to a significant number of new ideas and possibilities to further the research area.The control of surface roughness and pore structure has recently become a very hot topic in the field of biomaterials and bioceramics field in terms of the effects on protein adsorption (e.g. from plasma). Preliminary studies will assess the nature of protein adsorption and their release kinetics. The work will move on to consider how this influences osteoclastic remodelling and osteoblast-mediated bone deposition. While mono-culture has often been used in the past, the importance of co-culture of the physiologically relevant cells is increasingly recognised as a way to provide improved understanding of the underlying mechanisms and processes of bone repair. The use of highly controlled, model 2.5D environments offers the potential to study in more detail the effects of scaffold architecture and surface roughness for the development of angiogenic and osteo-inductive bone graft substitutes.Furthermore, I intend to translate the findings made in 2.5D to the more challenging aspects of production of controlled 3D environments as part of this project. Over the course of the project, I seek to develop my expertise in live cell imaging to understand cell-cell interactions. Additionally, I will develop the skills and knowledge readily available in the research group, and explore how X-Ray microtomography (microCT) might be combined with the use of appropriate contrast agents. These include antibody conjugates for evaluation of angiogenesis and more broadly, to provide information about the role of the protein adsorption in bone repair.The outcome of the investigations will be an improved understanding of the influence of protein adsorption on bone graft substitutes on bone repair and further insights into the role of scaffold architecture and surface topography in directing cell behaviour.