Gel-cast glass-ceramic tissue scaffolds of controlled architecture produced via stereolithography of moulds

Abstract

Two glass-ceramic scaffolds with a simple cubic structure of 500 µm square ligaments and square channels of width 400 or 600 µm have been fabricated by gel-casting into moulds produced by stereolithography, followed by mould removal, polymer burnout and sintering. The scaffolds have crushing strengths of 41 ± 14 and 17 ± 5 Mpa, respectively. Using a method of assembling discrete slices of scaffold, we are able to study cell behaviour within a scaffold by disassembly. Both scaffold structures were seeded with primary human osteoblasts and these penetrate, adhere, spread and proliferate on the scaffold structure. The larger channel diameter scaffold shows a greater cell population (despite its smaller surface area) and more pronounced production of ECM components (collagen and mineralization) with increased time in culture. Studies of sectioned scaffolds show that cell density and ECM production decrease with depth and that the difference between the two scaffold architectures is maintained.

Bioactive glass-ceramic scaffolds by additive manufacturing and sinter-crystallization of fine glass powders

“…The first experiences were presented in the review paper by Gmeiner et al, 1 according to which the approaches can be roughly divided into technologies for indirect printing and technologies for direct printing. Indirect printing corresponds to the manufacturing of polymeric replicas, e.g., by means of stereolithography, for the gel-casting of glass powders, 2,3 in analogy with what was done with other bioceramic powders. 4,5 Sintering occurs after template removal and burn-out of organic additives.…”

Hierarchical structures of β-TCP/45S5 bioglass hybrid scaffolds prepared by gelcasting

“…Several methods have been developed for processing three-dimensional (3D) scaffolds (Deville et al, 2006;Lin et al, 2008;Kim et al, 2009;Chopra et al, 2012;. Evidently, each of these techniques in spite of its advantages will have inherent drawbacks, and cannot fully satisfy some characteristics required for an ideal scaffold, for example, suitable mechanical strength, controlled total porosity and pore sizes, and well-defined pore connectivity .…”

“…Among all processing routes for fabricating bioceramic scaffolds, gel-casting of foams is an interesting technique to prepare scaffolds with relatively large-sized pores, high mechanical strength (Chopra et al, 2012;, reasonable interconnected pore channels and, mainly, by its ability for mass reproduction (Wu et al, 2011).…”

Photocrosslinkable Materials for the Fabrication of Tissue-Engineered Constructs by Stereolithography

“…A similar approach was used by Kim et al [49] to produce hydroxyapatite scaffolds, using lost-moulds fabricated by microstereolithography. Recently, Chopra et al [29] produced glass-ceramic (apatite-mullite glass-ceramic, LG112) scaffolds with simple cubic structure, by gel-casting into moulds produced by stereolithography (Fig. 20a).…”

“…bone, skin, neurons), due to its accuracy, precision, resolution and ability to process a large [29] variety of polymer and ceramic materials at physiological temperatures in the presence of cells and growth factors. In spite of current advances, there is a need to produce photocurable systems exhibiting appropriate biocompatibility, biodegradability and cellular interaction to allow the fabrication of scaffolds mimicking the natural ECM constitution and organization.…”