Processing methods for making porous bioactive glass‐based scaffolds—A state‐of‐the‐art review

Abstract

Bioactive glasses exhibit the unique ability of bone bonding, thus creating a stable interface by stimulating bone cells toward mechanisms of regeneration and self‐repair activated by ionic dissolution products. Therefore, 3D glass‐derived scaffolds can be considered ideal porous templates to be used in bone tissue engineering strategies and regenerative medicine. This review provides a comprehensive overview of all technological aspects relevant to the fabrication of bioactive glass scaffolds, including the fundamentals of materials processing, a summary of the conventional porogen, and template‐based methods and of recent additive manufacturing technologies, which are promising for large‐scale production of highly reproducible and reliable implants suitable for a wide range of clinical applications.

Strontium- and Cobalt-Doped Multicomponent Mesoporous Bioactive Glasses (MBGs) for Potential Use in Bone Tissue Engineering Applications

“…There is a long history of successful applications of bioactive glasses (BGs) in the management of bone-related diseases and disorders, as they could improve osteogenesis both in vitro and in vivo [1][2][3][4]. The initial types of BGs were synthesized by using a simple melt-quenching method; however, the high temperatures applied to prepare such glasses (typically around 1500 • C) are considered a critical limitation when incorporation of biomolecules into BGs is a goal to achieve an improvement in biological outcomes [5,6]. On the contrary, sol-gel glasses could be synthesized at lower temperatures and provide better opportunities for drug delivery strategies [7][8][9].…”

Dolomite-Foamed Bioactive Silicate Scaffolds for Bone Tissue Repair

“…Implantation of three-dimensional (3D) porous scaffolds mimicking the trabecular architecture of cancellous bone is an excellent strategy to restore small-to mid-size defects of the osseous tissue due to fracture, bone resection surgery, or congenital diseases [1]. Using manmade biomaterials for making scaffolds is an advantageous approach that allows overcoming the limitations of transplant tissues (i.e., bone autograft, allograft, and xenograft), such as material shortage, risk of disease transmission from the donor to the patient, unpredictable resorption rate, and ethical/religious concerns [2,3].…”

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

“…The 3D printing process builds a 3D object from a CAD model, usually by adding material through a layer by layer strategy. The most popular and affordable method to produce 3D-printed BG scaffolds involves the continuous deposition of a glass-based filament onto a building platform [61]. This approach is also called robocasting or robotic deposition; a schematic representation of a 3D printer for robocasting is shown in Figure 6 The material is extruded through a nozzle by mean of pressurized air under controlled velocity and pressure.…”

“…In fact, the quality of the final scaffold is strongly dependent on the extrusion process and the characteristics of the ink used for printing. In order to ensure a good outcome of the process and reliably reproduce the given pattern, a proper setting of printing parameters is needed in accordance with the rheological properties of the ink [61]. From a qualitative point of view, it is of paramount importance to maintain the filament straight upon extrusion to avoid the distortion of the structure and to preserve the original design.…”