Effect of Nano-sized Bioactive Glass Particles on the Antibacterial and Angiogenic Properties of Collagen Composites

G. VARGAS; J. RIVADENEIRA; L. HARO DURAND; M. ROMERO; R. VERA MESONES; V. CADENA; P. ZAGO; C. AUDISIO; V. MOURIÑO,; A. R. BOCCACCINI; A. GORUSTOVICH

Jena, Alemania

Simposio; European Symposium on Biomaterials and related areas; 2011

This work investigated the effect of adding nanoscale silicate bioactive glass particles (n-BG) on the antibacterial and angiogenic properties of bovine type I collagen/n-BG composites. 10 wt% of nano-sized (20-30 nm) bioactive glass particles of 45S5 Bioglass® composition were used to prepare composite films. The antibacterial activity was studied using Staphylococcus aureus (ATCC 29213). Neither collagen nor collagen/n-BG films were seen to affect significantly the viability of the bacterial strain under investigation. The angiogenic response was evaluated using the quail chorioallantoic membrane (CAM) as an in-vivo model of angiogenesis. Fertilized eggs of Japanese quail, were incubated in-ovo at 37°C, cracked at embryonic day 3 into 6-well plates, and cultured further ex-ovo. Collagen and collagen/n-BG films (5 mm diameter, 110-120 µm thick) were placed at day 7 on the CAMs. The embryos were incubated further at 37ºC for 24 h. CAMs were fixed with 4% paraformaldehyde/2% glutaraldehyde in PBS. Quantification of angiogenesis was accomplished by counting the number of blood vessel branch points on the delimited surface beneath the implant. Therefore, the CAMs were processed for light microscopy examination. The number of blood vessels branch points was increased to 41% on CAMs implanted with collagen/n-BG films in comparison to those treated with collagen alone. Microscopically, both films were adherent to the chorion without invading the mesenchyme. At some points, epithelial cells from the chorion invaded the collagen/n-BG films. Moreover, no significant increase of the mononuclear cell infiltrate was observed in the CAMs treated with the collagen/n-BG films with respect to collagen-treated samples, ruling out the possibility that the angiogenic activity exerted by the collagen/n-BG films was the consequence of the triggering of an inflammatory response. This experimental study provides the first evidence that collagen/n-BG films are able to induce a strong angiogenic response.