Comparative study of two silica mesoporous materials (SBA-16 and SBA-15) modified with a hydroxyapatite layer for clindamycin controlled delivery

Mesoporous silica materials are very promising for biomedical applications due to their superficial area and bioactive behavior and have been widely investigated for control drug release. The bioactive behavior of these materials have been attributed to silanol groups and/or to textural properties. In the present work we studied the bioactive behavior of two mesoporous materials with different textural properties, the formation of an apatite coating on the mesoporous walls and their effect on the controlled delivery of clindamycin, at two different pH conditions. It was found that the textural properties are a determinant factor in the bioactive behavior of these materials; SBA-15 showed a higher bioactive response than SBA-16 after 8 d immersion in simulated body fluid. Also, SBA-15 was more effective for clindamycin drug release; however both materials are very promising as drug carriers. The formation of hydroxyapatite crystallites on the mesoporous walls resulted in new textural properties with a new framework configuration that affects the delivery properties of the mesoporous materials. Additionally, the citotoxicity and osteogenesis of SBA-15 and the modified SBA-Ha were evaluated. The mesoporous silica materials were non-toxic for the cells allowing viability for the studied period with an increase proliferation for the cells exposed to SBA-15/Ha. The results showed that SBA-15 and SBA-15/Ha are osteogenic materials, promoting the formation of mineralization nodules, associated to osteogenesis. (C) 2017 Published by Elsevier Inc.