In vitro bioactivity and drug release kinetics studies of mesoporous silica-biopolymer composites M. Narasimha Reddy 1 • K. K. Cheralathan 1 • S. Sasikumar 1 Published online: 23 July 2015 Ó Springer Science+Business Media New York 2015 Abstract Targeted drug delivery systems become highly significant in certain diseases where the required dosage of drug cannot be delivered due to poor blood circulation in the targeted hard tissues. The present study reports a simple method of preparing mesoporous silica (SBA-15)/ Biopolymer composite and loading an antibiotic in the silica scaffold which may find applications in bone drug delivery system. The SBA-15 was prepared under different conditions and analyzed for its texture and structural properties. The as prepared silica was characterized by low angle X-ray diffraction and BET surface area measurement which shows mesoporosity associated with hexagonally organized channels, a narrow pore size distribution and a large surface area. Chitin and Chitosan were the biopoly- mers used in the preparation of composites and bioactivity of the composites was investigated in the SBF medium. Ciprofloxacin was used as a model drug molecule in the drug delivery studies as its molecular size is suitable for inclusion within the mesopores of the SBA-15 material. The in vitro drug release was investigated in the simulated body fluid medium. The mesoporous silica’s were found to be highly bioactive and found to possess sustained drug delivery kinetics. Keywords Mesoporous silica Á Drug delivery system Á Antibiotics Á Powder X-ray diffraction 1 Introduction Mesoporous materials contain ordered arrays of uniform nanochannels with larger pore size, and high surface area which found lot of applications in separation, catalysis, sensors and devices [1, 2]. Two most common types of periodic silicas are MCM-41 and SBA-15. SBA-15 materials have been prepared in acidic conditions with poly (alkylene oxide) tri-block co-polymers. They usually have wider pores and thicker pore walls than MCM-4. Both solids have periodically ordered structures, which consist of two dimensional hexagonal arrays of uniform mesopores. SBA-15 is by far the largest pore sized mesoporous material with highly ordered hexagonally arranged mesochannels, with thick pore walls, adjustable pore size from 3 to 30 nm, and high hydrothermal and thermal stability [3]. Such features show the high potential of SBA-15 as a support for drug delivery applications [4]. Very high pore volumes of up to 1 cc/g and surface areas up to 1000 m 2 /g can be achieved in ordered meso- porous silica’s and this feature make it suitable to act as a drug carrier for drug delivery applications [5]. Ordered mesoporous silica possesses very good biocompatibility and various methodologies were adopted to deliver the drugs from ordered mesoporous silica into simulated biological fluids [6]. The release kinetics of the adsorbed drug from the carrier depends on the pore size, size of the drug molecule and the method adopted for drug loading [7, 8]. The adsorption and release of drug from the drug carrier is decided by the chemical relationship between drug molecule and pore walls of mesoporous matrices. Surface modification of the silanol groups at the surface of the mesopore walls will enhance the adsorption and confinement of drug molecules in the drug carrier and also & S. Sasikumar vitsasi@yahoo.co.in 1 Materials Chemistry Division, School of Advanced Sciences, VIT University, Vellore 632014, Tamil Nadu, India 123 J Porous Mater (2015) 22:1465–1472 DOI 10.1007/s10934-015-0027-5