Bioglass ®45S5 Stimulates Osteoblast Turnover and Enhances Bone Formation In Vitro: Implications and Applications for Bone Tissue Engineering

Abstract

We investigated the concept of using bioactive substrates as templates for in vitro synthesis of bone tissue for transplantation by assessing the osteogenic potential of a melt-derived bioactive glass ceramic (Bioglass 45S5) in vitro. Bioactive glass ceramic and bioinert (plastic) substrates were seeded with human primary osteoblasts and evaluated after 2, 6, and 12 days. Flow cytometric analysis of the cell cycle suggested that the bioactive glass-ceramic substrate induced osteoblast proliferation, as indicated by increased cell populations in both S (DNA synthesis) and G2/M (mitosis) phases of the cell cycle. Biochemical analysis of the osteoblast differentiation markers alkaline phosphatase (ALP) and osteocalcin indicated that the bioactive glass-ceramic substrate augmented osteoblast commitment and selection of a mature osteoblastic phenotype. Scanning electron microscopic observations of discrete bone nodules over the surface of the bioactive material, from day 6 onward, further supported this notion. A combination of fluorescence, confocal, transmission electron microscopy, and X-ray microprobe (SEM-EDAX) examinations revealed that the nodules were made of cell aggregates which produced mineralized collagenous matrix. Control substrates did not exhibit mineralized nodule formation at any point studied up to 12 days. In conclusion, this study shows that Bioglass 45S5 has the ability to stimulate the growth and osteogenic differentiation of human primary osteoblasts. These findings have potential applications for tissue engineering where this bioactive glass substrate could be used as a template for the formation of bioengineered bone tissue.

Biocompatibility and bioactivity of porous polymer-derived Ca-Mg silicate ceramics

“…5). The stimulatory and dose-dependent osteogenic effects of these 22 ionic products have been well-documented in a number of studies [10,53,54,55] shown to increase the bone mineral density in both men and premenopausal women [60,61]. formation observed in the present study.…”

Bioactive glass and glass-ceramic scaffolds for bone tissue engineering

“…During the past three decades, however, the strategy in biomaterial research began to shift from developing biomaterials with a bio-inert tissue response to producing bioactive components that could elicit a controlled action and reaction in the physiological environment [1]. Since the late 1990's and the beginning of the new millennium, great potential has been attributed to the application of bioactive glasses in tissue engineering and regenerative medicine [39][40][41][42][43]. Bone tissue engineering is one of the most exciting future clinical applications of bioactive glasses.…”

“…Key mechanisms leading to enhanced new bone growth are now known to be related to the controlled release of ionic dissolution products from the degrading bioactive glass, especially critical concentrations of biologically active, soluble silica and calcium ions [8,191]. Recent studies have shown that bioactive (partially) resorbable glasses and their ionic dissolution products enhance osteogenesis by regulating osteoblast proliferation, differentiation, and gene expression [7,41,51,[191][192][193][194][195][196][197][198].…”

Bone tissue engineering by using a combination of polymer/Bioglass composites with human adipose-derived stem cells

“…Indeed, numerous in vivo and in vitro studies have shown that 45S5 Bioglass ® can stimulate bone regeneration (Bosetti et al 2003;Gough et al 2004;Livingston et al 2002;Loty et al 2001;Tsigkou et al 2007;Xynos et al 2000). As a result, Bioglass ® is said to be both osteoproductive and osteoconductive.…”