Bioactive xerogel

Compared with the melt process, the sol-gel route for bioactive glass synthesis is a bottom-up process. This means versatility bioactive glasses can be made as nanoporous (mesoporous) powders/monoliths, submicron/nanoparticles [23], or scaffolds [24]. Figure 43.2 shows a nanoporous surface of a bioactive xerogel and monodispersed bioactive glass particles with diameters of 220 nm. 

Jun S-H et al (2010) A bioactive coating of a silica xerogel/chitosan hybrid on titanium by a room temperature sol-gel process. Acta Biomater 6 302-307... 

The sol-gel-derived silica (xerogel) has been found to be bioactive, or to possess the ability to form calcium phosphates on the surface in the simulated body fluid (SBF) (Kokubo, 1994 Cho, 1995). This fact suggested that the sol-gel-silica can be used as temporary implants, fillers or drug-delivery devices in bone-repair. From this sense, a research group in Finland has been studying the applicability of the sol-gel-derived silica fibers in the medical field. 

Heinemann, S., Heinemann, C., Wenisch, S., Alt, V., Worch, H., Hanke, T, 2013. Calcium phosphate phases integrated in silica/collagen nanocomposite xerogels enhance the bioactivity and ultimately manipulate the osteoblast/osteoclast ratio in a human co-culture model. Acta Biomaterialia 9,4878-4888. 

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