Covalent TiO2/pectin microspheres with Fe3O4 nanoparticles for magnetic field-modulated drug delivery

Covalent TiO2-co-pectin microspheres containing Fe3O4 nanoparticles were developed through an ultrasound-induced crosslinking/polymerization reaction between the glycidyl methacrylate from vinyl groups in TiO2 and in pectin zeta-potentials became less negative in the nanostructured microspheres, caused by the presence of both inorganic particles in the negatively charged pectin. The nanostructured pectin microspheres showed an amoxicillin release rate slower than that of pure pectin microspheres. The proposed microspheres were found to be a sustained release system of amoxicillin in the acid medium. Furthermore, the antibiotic release may be modulated by exposition of the microspheres to a remote magnetic field. In practical terms, the nanostructured microspheres could deliver a larger proportion of their initial load to specific site of action. The cytotoxic concentrations for 50% of VERO cells (CC50), calculated as the concentration required to reduce cell viability by 50% after 72 h of incubation, for pectin-only microspheres and nanostructured pectin microspheres were 217.7 +/- 6.5 and 121.5 +/- 4.9 pg mL(-1), respectively. The obtained CC50 values indicated acceptable cytotoxic levels for an incubation period of 72 h, showing that the pectin microspheres have a great pharmacological potential for uses in biological environments, even after the introduction of both Fe3O4 and TiO2. (C) 2014 Elsevier B.V. All rights reserved.