Encapsulation of rifampin in a polymeric layer-by-layer structure for drug delivery.

Rifampin (RIF) is a bactericidal antibiotic drug and potent inducer of hepatic and intestinal cytochrome P-450 (CYP-450) enzyme systems. Given by mouth or intravenously, it can cause numerous clinical drug interactions; thus, alternative systems of drug delivery that bypass some or all of its toxic effects are well worth investigating. In this study, a controlled layer-by-layer (LBL) process of encapsulating RIF in biocompatible alginate and chitosan polymers loaded onto Fe3 O4 nanoparticles was developed. Fe3 O4 nanoparticles were synthesized from FeCl3 ·6H2 O using a hydrothermal procedure. Fluorescent molecular beacons containing RIF molecules and Texas Red were loaded onto the surfaces of Fe3 O4 nanoparticles. The loaded nanoparticles were encapsulated in alginate and chitosan layers with alternating negative and positive surface charge using an LBL self-assembly method. Subsequently, by removing the Fe3 O4 template particles, polymeric capsules containing RIF were obtained. Ultraviolet-visible spectrophotometry employed to determine optimized conditions for loading RIF, measure the amount of RIF loaded onto the surface of the nanoparticles under optimized conditions, and study drug-release capability. Scanning electron microscopy was used to characterize the morphology of unloaded and loaded nanoparticles. X-ray diffraction and Fourier transform infrared spectroscopy were applied to demonstrate the production of nanoparticles and loading of RIF onto them. Zeta potential analysis was used to determine the size and surface potential of the loaded polymeric layers. After removal of the core template, confocal fluorescence microscopy was used to isolate polymeric capsules containing RIF. The average size of the nanoparticles obtained was 23 nm. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 905-913, 2018.