PLA–PEG grafted hollow magnetic silica microspheres as the carrier of iodinated contrast media

In this work, hollow magnetic silica microspheres (HMS) were synthesized by the template method, polyethylene glycol (PEG) and poly(lactic acid) (PLA)-grafted hollow magnetic microspheres HMS@PLA–PEG were successfully prepared through ring-opening polymerization method. Ioversol was loaded into HMS@PLA–PEG by physical coating, and the drug loading content was up to 39.4%. It also exhibited a slower and steady release than HMS and the cumulative release was up to 55.1% at physiological pH, which implied the PLA–PEG could prolong the circulation time. Meanwhile, to improve the efficiency of contrast, we have developed composite microspheres encapsulating superparamagnetic iron oxide (Fe3O4) as magnetic target for increasing the local concentration of the contrast media and expecting to put magnetic resonance imaging (MRI) and computed tomography (CT) technology together to apply in medical applications. Furthermore, the cytotoxicity assay in vitro was also investigated. The results revealed the ioversol-loaded HMS@PLA–PEG exhibited low toxicity at a higher concentration, even it is up to 400 μg/mL. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44914.