Magnetic brain targeting of naproxen-loaded polymeric micelles: pharmacokinetics and biodistribution study

Abstract

The blood brain barrier is a major obstacle to the entry of the majority of CNS-active agents. In the present research, the potential of magnetic polymeric micelles (MPMs) for brain-targeting of naproxen was evaluated. The MPMs were made of methoxy poly(ethyleneglycol)-poly (caprolactone) copolymer and super paramagnetic iron oxide nanoparticles (SPIONs). To investigate the impact of particle size on the in vivo biofate of nanoparticles, MPMs with two different sizes were prepared. The prepared magnetic polymeric micelles had diameters of 137 ± 3.5 nm (MPM137) and 242 ± 6.2 nm (MPM242) and their surface charges were about −6.5 and − 4.5 mV, respectively. Pharmacokinetic and biodistribution of nanoparticles were characterized in rats using an external magnet of 0.4 Tesla field strength located on the skull of anesthetized animals. Significant differences in volumes of central as well as peripheral compartments were observed between both MPM formulations and free naproxen solution. After 8 h of administration, the brain concentration of naproxen was shown to be higher in the case of MPM137 in comparison with MPM242 and free drug. The findings revealed that the polymeric magnetic micelles with diameters smaller than 150 nm could be initially considered as a promising carrier to improve therapeutic agent accumulation in the brain for the treatment of CNS diseases.