Tailoring the Structure of Bioactive Glasses: From the Nanoscale to Macroporous Scaffolds

Abstract

Abstract:Bioactive glasses are going to play an essential role in the manufacture of 3D scaffolds for bone tissue engineering. Mimicking natural bone, synthetic scaffolds must be tailored at a hierarchy of scales. First, the glasses composition must be carefully designed at the atomic-molecular level to ensure bioactivity and beneficial effects including capabilities for enhance osteogenesis and vascularization or to exert bactericide action. Moreover, the glasses structure need to be designed at the nanometric scale. With this purpose, mesoporous bioactive glasses, exhibiting ordered arrangements of nanometric pores, are optimum candidates. The microstructure of glasses must also be designed to achieve suitable interactions with living cells. Finally, the scaffolds obtained with bioactive glasses must display interconnected pores over 100 µm to made possible bone cell ingrowths and angiogenesis. In this article, the advances in the field of bioactive glasses through the control of the chemical, nanometer scale, microstructural properties and architectural features are presented and discussed. A detailed control of these four levels of matter organization will allow optimizing the biological response of bioactive glasses when used in bone tissue regeneration. AbstractBioactive glasses are going to play an essential role in the manufacture of 3D scaffolds for bone tissue engineering. Mimicking natural bone, synthetic scaffolds must be tailored at a hierarchy of scales. First, the glasses composition must be carefully designed at the atomic-molecular level to ensure bioactivity and beneficial effects including capabilities for enhance osteogenesis and vascularization or to exert bactericide action. Moreover, the glasses structure need to be designed at the nanometric scale. With this purpose, mesoporous bioactive glasses, exhibiting ordered arrangements of nanometric pores, are optimum candidates. The microstructure of glasses must also be designed to achieve suitable interactions with living cells. Finally, the scaffolds obtained with bioactive glasses must display interconnected pores over 100 µm to made possible bone cell ingrowths and angiogenesis. In this article, the advances in the field of bioactive glasses through the control of the chemical, nanometer scale, microstructural properties and architectural features are presented and discussed.A detailed control of these four levels of matter organization will allow optimizing the biological response of bioactive glasses when used in bone tissue regeneration.

3D Printing of Hierarchical Scaffolds Based on Mesoporous Bioactive Glasses (MBGs)—Fundamentals and Applications

“…Fabrication of hierarchical MBG-based scaffolds is a challenge-in fact, mesopore size is almost three orders of magnitude lower than that of osteoblasts and, therefore, macroporosity must be somehow introduced in the final product in order to allow cell colonization and tissue in-growth [46].…”

Comparison of the effects of 45S5 and 1393 bioactive glass microparticles on hMSC behavior

“…This has opened a whole new exciting field of research of cell stimulation by synthetic materials without the need for organic growth factors . Furthermore, mesoporous silica based glasses can be produced as micron and submicron sized SiO 2 ‐CaO or SiO 2 ‐CaO‐P 2 O 5 particles for the storage of signaling molecules and their localized release at the implantation site . The design of bioactive glass structures with nano to micro scale dimensions results in an increase in the glasses' bioactivity and enables the loading of therapeutic biomolecules to further stimulate the tissue regeneration process …”

“…13 Furthermore, mesoporous silica based glasses can be produced as micron and submicron sized SiO 2 -CaO or SiO 2 -CaO-P 2 O 5 particles for the storage of signaling molecules and their localized release at the implantation site. 14 The design of bioactive glass structures with nano to micro scale dimensions results in an increase in the glasses' bioactivity and enables the loading of therapeutic biomolecules to further stimulate the tissue regeneration process. 15,16 Today, different classes of silicate BAGs are available on the market for clinical applications such as NovaBone, Biogran V R and Perioglas which are based on the 45S5 Bioglass V R composition.…”

The influence of phosphorus precursor on the structure and properties of SiO 2 –P 2 O 5 –CaO bioactive glass

“…Additionally, the sol-gel process provides a versatile method to design or tailor BG with different structure, composition and morphology 12 .…”