title: Mesoporous silica/apatite nanocomposite: special synthesis route to control local drug delivery.
abstract: Synthetic hydroxyapatite is widely used in medicine and dentistry due its notable biocompatibility and bioactivity properties. The hydroxyapatite incorporation into silica has demonstrated excellent bioactivity or biodegradability, according to the content of calcium ions. Procedures to obtain ordered mesoporous silicates rely on the micelle-forming properties of a surfactant, whose chemical composition, size and concentration control the structural dimensions of the final material. This paper reports the synthesis of two types mesoporous materials: pure MCM-41 and a nanocomposite of apatite and mesoporous silica, MCM-41-HA. The samples were charged with atenolol as a model drug and in vitro release essays were carried out. The bioactivity behavior was investigated as a function of soaking time in simulated body fluid. The materials were characterized by X-ray diffraction, N2 adsorption, FTIR spectroscopy, scanning electron microscopy, dispersive energies spectroscopy, and transmission electron microscopy. The influence of the release rate of atenolol molecules from pure MCM-41 mesoporous and containing hydroxyapatite was demonstrated, since it results in a very slowly drug delivery from the nanocomposite system.
authors.affiliation: Laboratório de Biomateriais, Centro de Desenvolvimento da Tecnologia Nuclear, CDTN/CNEN, Avenida Presidente Antônio Carlos 6.627, Campus da UFMG, Pampulha CEP 31270-90, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: A
authors.initials: A
authors.lastname: Sousa
authors.forename: K C
authors.initials: KC
authors.lastname: Souza
authors.forename: E M B
authors.initials: EM
authors.lastname: Sousa
mesh_terms: D000327:Adsorption / Q000187:drug effects; D001031:Apatites / Q000138:chemical synthesis*; D001262:Atenolol / Q000494:pharmacology; D001826:Body Fluids / Q000187:drug effects; D016503:Drug Delivery Systems; D007700:Kinetics; D046529:Microscopy, Electron, Transmission; D053761:Nanocomposites / Q000737:chemistry*; D009584:Nitrogen / Q000737:chemistry; D016062:Porosity / Q000187:drug effects; D012822:Silicon Dioxide / Q000138:chemical synthesis*; D017550:Spectroscopy, Fourier Transform Infrared; D017356:Synchrotrons; D014961:X-Ray Diffraction
chemical_list: D001031:Apatites; C509968:MCM-41; D001262:Atenolol; D012822:Silicon Dioxide; D009584:Nitrogen