Loading of antibiotic molecules into organically modified layered calcium silicate

Abstract

Calcium silicate is the basic component of bioactive materials that directly bond to living bone (bone-bonding property) in the body environment because calcium silicate can easily form a hydroxyapatite layer on its surface after exposure to body fluids. The organic modification of calcium silicate ceramics is expected to improve their physicochemical properties. Organic modifications of layered inorganic substances have been studied to allow drug loading and sustained release through structural changes. However, few studies have investigated the effect of organic modifications on drug-release carriers. In this study, layered calcium silicate hydrate (C-S-H) prepared via a hydrothermal process was chemically modified with alkyl groups using alkoxysilane. In addition, the loading behavior of the antibiotic levofloxacin was quantitatively analyzed. Structural analysis of the synthesized samples indicated that the interlayer distance and amount of organic content in C-S-H increased with increasing carbon chain length and concentration of alkoxysilane. Levofloxacin was successfully incorporated into the modified C-S-H. It has been suggested that drug incorporation occurs mainly via surface adsorption rather than intercalation into the interlayer.

Keywords

• Layered calcium silicate hydrate (C-S-H)
• drug loading
• interlayer distance
• alkoxysilane
• organic modification