Magnetic targeting effect of methotrexate-loaded Fe3O4-PLLA-PEG-PLLA microspheres prepared in supercritical CO2

Abstract： The magnetic targeting effect of methotrexate-loaded Fe3O4-poly (L-lactide)-poly (ethylene glycol)-poly (L-lactide) magnetic composite microspheres (MTX-Fe3O4-PLLA-PEG-PLLA MCMs, MMCMs) prepared by co-precipitation (C) and microencapsulation (M) in a process of suspension-enhanced dispersion by supercritical CO2 (SpEDS) was evaluated. The observations of movements and aggregations of MMCMs indicate a good magnetic response in vitro. The results of Prussian blue iron-staining in tumor and the distribution of MTX in S-180-bearing KM mice demonstrate that MMCMs with magnetic field induction could effectively target to tumors. The MTX concentration in tumors treated with free MTX, MMCMs(C) and MMCMs(M) were 8.13±0.46 ng/mL, 138.71±66.22 ng/mL and 282.11±9.36 ng/mL, respectively. This reveals that MMCMs(M) with magnetic field induction possessed a much more remarkable targeting effect than MMCMs(C) and free MTX formulations. This study demonstrates that MMCMs(M) could effectively response to the magnetic induction both in vitro and in vivo, and have potential for application in magnetic targeting therapy of solid tumors. ?????