Bioactive glass as precursor of designed‐architecture scaffolds for tissue engineering

Abstract

In this work, the conditions to obtain concentrated and fluid suspensions from a bioactive glass (55-SiO(2); 41-CaO; 4-P(2)O(5); mol %) were investigated. The influence of the heat treatment of the glass on the specific surface area, solubility, bioactivity, and finally on their dispersion characteristics was studied. Zeta potential and viscosity measurements were carried out, and based on the obtained results, the best dispersant was selected. The optimum concentration of dispersant, maximum content of solid and time of mixing were also investigated. Slurries containing 50 vol % could be obtained calcining the glass at 1100 degrees C and using Darvan 811 (sodium polyacrylate) as dispersant. Scaffolds with designed architecture were prepared from these suspensions combining the gelcasting method and the stereolithography technique. A polymeric negative (replica of the desired structure) was previously obtained by stereolithography. The slurry was cast into the molds and then polymerized (gelcasting method). The negative was eliminated by heat treatment. After sintering at 1300 degrees C, scaffolds with interconnected porosity and three-dimensional channels of 400-470 microm and macropores of 1.4 microm were obtained.

Preventing bacterial adhesion on scaffolds for bone tissue engineering

“…There are many manufacturing methods ranging from the more conventional ones, which lead to randomly interconnected porous scaffolds and that which are principally based on the incorporation of porogen particles [66] , use of foam replica technique [67] , gel-casting of foams [68] , cold isostatic pressing [69] , deproteinization of bovine bone [70] , particulate leaching [71] , freeze-drying [72] , gas foaming [73] , and a combination of the methods [74] ; to more sophisticated technologies based on solid free form (SFF) fabrication such as rapid prototyping (RP). RP techniques allowed accurate control in the macro-microporosity scales and fabricating custom-made implants, which allowed the fabrication of scaffolds both of bioceramic and metallic nature [75] .…”

“…Thus, the scaffold architecture can be adjusted and optimized to attain the adequate mechanical response, accelerate bone regeneration process, and guide bone formation with the anatomic cortical-trabecular structure [78] . Several RP techniques have been used for scaffolds preparation, such as robocasting (RC), selective laser sintering (SLS), selective laser melting (SLM), stereolithography (SLA) [79][80][81][82] , 3D printing (3DP) [83][84][85] and fused deposition modeling (FDM) [86,87] . Herein we reviewed the two main RP techniques, namely robocasting (RC) and selective laser based techniques as SLS and SLM, used for the manufacture of bioceramic and metallic scaffolds by itself or in combination with polymers.…”

Fabrication Of Scaffolds From Ti6Al4V Powders Using The Computer Aided Laser Method

“…Its task is to ensure access, for cells, to nutrients and to ensure their growth on its surface. It is important that a small diameter of pores needs to be taken into accounting when designing this type of materials [5][6][7][8][9][10][11][12].…”

Design of new hybrid nanomaterials with molecular gates as nanodevices for therapeutic applications.

“…38 This modification of the inorganic matrix by the incorporation of organic components, either on the silica surface, as part of the silicate walls, or trapped within the channels, permits a precise control over the surface properties and pore sizes of the mesoporous sieves for specific applications and usually stabilize the materials towards hydrolysis. 45 A wide range of properties can also be affected by this mixing of inorganic and organic moieties in the mesostructures. provide mechanical, thermal, or structural stability, whereas organic groups can introduce flexibility into the framework, or change, for example, the optical properties of the solid.…”

“…42,43 In this context many processes have been developed to prepare macroporous supports, such as replicas of porous sponges and coral exoskeletons, production of gas bubbles via gas evaporation, chemical reactions, and introduction of porogens (such as organic volatile particles) in a ceramic slip and gel-casting, either alone or in combination with a multiple tape-casting method. [44][45][46] However, pore size, shape and its interconnectivity, cannot be fully controlled in these approaches. In contrast, rapid prototyping (RP) is a good alternative to fulfil requirements for manufacturing suitable scaffolds for different clinical applications and individuals.…”