Materials World Network: Nano-Macro Porous Glass Bone-Scaffolds

细胞生物学和材料科学的进步已经产生了通过在生物相容性支架上向损伤部位提供健康的祖细胞来修复或再生丢失或受损组织的概念。这种最理想的治疗方法的成功取决于细胞可以附着并形成牢固结合的3D结构的发展。制造这种支架的理想材料应该在生物力学上与宿主组织相似，并且必须是生物相容的，优选地是生物活性的，以便主动控制组织生长。这种方法的最成功的结果已经获得骨替代使用的骨支架由CaO-P2 O 5-SiO2基玻璃。大孔结构对于通过快速血管化和骨向内生长获得良好的植入物结合是必要的，然而理想的支架应由模拟结缔组织发育的细胞外环境的纳米孔组成。因此，理想的骨支架必须由纳米-大孔的双峰分布组成。不存在用于在具有规定的机械和生物相容性的生物活性玻璃中制造双峰孔隙率的工艺。因此，提出了一个综合的研究计划，用于制造骨支架，并在体外和现实的体内环境下证明其有效性（利用骨髓间充质干细胞进行牙槽骨再生）。溶胶-凝胶法将是玻璃制备的主要方法，其中双峰孔隙率将通过聚合诱导的相分离与溶胶-凝胶转变同时或经由大孔模板引入已建立的生物玻璃型组合物中。为了优化玻璃成分和工艺参数，我们将研究玻璃的本体和表面、骨-支架界面和新形成的骨的物理和化学结构。我们的目标将由来自埃及、葡萄牙、塞内加尔和美国的玻璃合成化学家、物理玻璃科学家、表面科学家、具有组织工程专业知识的牙医和生物力学专家组成的五个小组共同努力实现。在广泛的影响方面，该项目将有助于开发更好的治疗老年人或创伤患者骨组织丢失的方法。我们的新型生物活性纳米大孔玻璃支架不仅可以帮助骨科患者，而且还可以引入新的药物输送和细胞包封技术。它将展示材料科学和工程在推进医学前沿方面的好处。它还将帮助建立一个跨学科材料研究人员的重点材料世界网络，并为来自三大洲的四个国家的年轻科学家提供培训。该项目将在两个发展中国家创建第一个生物活性材料综合研究计划，从而为该研究领域的未来研究树立典范。该项目的影响将通过与美国国家科学基金会在利哈伊和普林斯顿大学的两个国际材料研究所的合作来扩大。该奖项由NSF国际科学与工程办公室的非洲和近东项目共同资助。

Advances in cell biology and material science have led to the concept of repairing or regenerating lost or damaged tissue by providing healthy progenitor cells to the injured site on a biocompatible scaffold. The success of this most desirable treatment rests on the development of 3D structures to which cells can attach and form firm bonds. The ideal material to make such scaffolds should be biomechanically similar to the host tissue and must be biocompatible, preferably be bioactive so as to actively control tissue growth. The most successful results of this approach have been obtained for bone replacement using bone-scaffolds made from CaO-P2O5-SiO2 based glasses. A macro porous structure is necessary to obtain good implant incorporation through rapid vascularization and bone ingrowth, yet an ideal scaffold should consist of nanopores that simulate the extracellular environment for the development of connective tissue. Thus an ideal bone-scaffold must consist of a bimodal distribution of nano-macro pores. The process for fabricating bimodal porosity in a bioactive glass with prescribed mechanical and biocompatibility properties does not exist. Therefore, a comprehensive research program is proposed for fabricating bone-scaffolds and demonstrating their efficacy under controlled in vitro and realistic in vivo environment (alveolar bone regeneration utilizing bone marrow mesenchymal stem cells). Sol-gel method will be the primary method of glass preparation in which bimodal porosity will be introduced in established Bioglass type compositions either by polymerization-induced phase separation simultaneously with the sol-gel transition, or via macroporous templates. To optimize the glass composition and processing parameters, we will investigate the physical and chemical structure of the bulk and surface of glass, the bone-scaffold interface, and newly formed bone. The very broad scope of our goal will be pursued collaboratively by glass synthesis chemists, physical glass scientists, surface scientists, dentists with expertise in tissue engineering, and biomechanics specialists, forming a team of five groups from Egypt, Portugal, Senegal and USA.With regard to broad impact, the project will help develop a better treatment of bone tissue loss in aging population or patients suffering from a trauma. Our novel bioactive nano-macro porous glass-scaffold would not only help orthopedic patients, but may also introduce new technology for drug delivery and cell encapsulation. It will demonstrate the benefits of materials science and engineering in advancing the cutting edge of medicine. It will also help establish a focused materials world network of researchers in cross-disciplinary materials research, and train young scientists in four countries from three continents with one common goal. The project will be creating the first comprehensive research programs of bioactive materials in two developing countries, and thus setting a model for future research in this area of research. The projects impact will be amplified via its alignment with NSFs two International Materials Institutes at Lehigh and Princeton Universities. This award is co-funded by the Africa and Near East Programs of the NSF Office of International Science and Engineering.