Sol-gel-based bioceramics: From materials to medicine

The progress of nanotechnology has opened the path for the development of new biomaterials. Recent developments have demonstrated that sol-gel bioceramics play an important role in the biomedical field due to their superior biological and mechanical properties. A bioactive hydroxyapatite (HA) is a common bioceramic that attaches to living tissues in vivo at body temperature. Sol-gel processes are now being used to produce bioactive coatings, powders, and substrates that can facilitate control over biological behavior of proteins and cells with broad clinical applications. It has been found that HA particles can down-regulate the expression of some cancerogenic genes in 432tumor cells. The nano-HA particles from the biodegradation of HA ceramics could penetrate the membranes of tumor cells. A rapid and economic sol-gel method has been designed to synthesize sodium silicate (Na₂SiO₃) into silica gel in large quantities. Sol-gel-based bioceramics have the potential to present unexpected excellent biological functions. Thus, the understanding and control of the interactions between bioceramics and biological entities may play one of the leading roles in the development of nanomedicine.