Bioactive Glass 13-93 as a Subchondral Substrate for Tissue-engineered Osteochondral Constructs: A Pilot Study

Abstract

Background Replacement of diseased areas of the joint with tissue-engineered osteochondral grafts has shown potential in the treatment of osteoarthritis. Bioactive glasses are candidates for the osseous analog of these grafts. Questions/purposes (1) Does Bioactive Glass 13-93 (BG 13-93) as a subchondral substrate improve collagen and glycosaminoglycan production in a tissue-engineered cartilage layer? (2) Does BG 13-93 as a culture medium supplement increase the collagen and glycosaminoglycan production and improve the mechanical properties in a tissue-engineered cartilage layer?Methods In Study 1, bioactive glass samples (n = 4) were attached to a chondrocyte-seeded agarose layer to form an osteochondral construct, cultured for 6 weeks, and compared to controls. In Study 2, bioactive glass samples (n = 5) were cocultured with cell-seeded agarose for 6 weeks. The cell-seeded agarose layer was exposed to BG 13-93 either continuously or for the first or last 2 weeks in culture or had no exposure. Results Osteochondral constructs with a BG 13-93 base had improved glycosaminoglycan deposition but less collagen II content. Agarose scaffolds that had a temporal exposure to BG 13-93 within the culture medium had improved mechanical and biochemical properties compared to continuous or no exposure. Conclusions When used as a subchondral substrate, BG 13-93 did not improve biochemical properties compared to controls. However, as a culture medium supplement, BG 13-93 improved the biochemical and mechanical properties of a tissue-engineered cartilage layer. Clinical Relevance BG 13-93 may not be suitable in osteochondral constructs but could have potential as a medium supplement for neocartilage formation.

Effects of borate‐based bioactive glass on neuron viability and neurite extension

“…In vivo , increased angiogenesis was found around subcutaneous implants of 13–93 B3 glass, and studies reported high levels of collagen and connective tissue remodeling around the glass . This report is supported in vitro by production of collagen I and IV and glycosaminoglycans into subchondral bioactive glass implants for potential use in osteochondral defects . Further clinical investigation of borate glass (13‐93 B3) for use in long‐term, non‐healing wounds showed a significant decrease in wound size within 1–3 months of treatment and return of sensation to the scar area .…”

Bioactive glass in tissue engineering

“…When co-cultured with bovine chondrocyte-seeded agarose hydrogels, porous scaffolds of a silicate 13–93 bioactive glass served as a medium supplement for culturing tissue-engineered cartilage in vitro [155,156]. Constructs were cultured in serum-free, chemically defined medium supplemented with TGF-β 3 (10 ng ml −1 for the first 14 days of culture) [157].…”

Reprint of: Review of bioactive glass: From Hench to hybrids

“…12d), which means that mechanical properties can be lower than might be expected; for example, the 45S5 glass-ceramic foams had a compressive strength of 0.4 MPa (90% porosity). However, by choosing an optimal polymer foam and by optimizing the amount of glass particles (<10 lm) used in the slurry (35 vol.%), compressive strengths of 11 MPa were obtained with 13-93 scaffolds, with 85% porosity and pore sizes ranging from 100 to 500 lm [173].…”