Preparation of polymer microbubbles encapsulated iron oxide nanopraticles and doxorubicin and characterization in vitro

Abstract

Objective To prepare a kind of superparamagnetic iron oxide (SPIO) and doxorubicin loaded multifunctional polymer microbubbles (MPMBs),and to explore its potential application as an ultrasound(US)/magnetic resonance (MR) imaging contrast agent in vitro.Methods The MPMBs and normal polymer microbubbles (PMBs) were made by double emulsion and freeze-drying methods.The physical property,drug encapsulation efficiency and the drug-loading efficiency of MPMBs were determined,and the release property and US/MR imaging enhancement of MPMBs were observed.Results The MPMBs had a regular shape and narrow size distribution.The drug encapsulation efficiency was (60.20±2.69) ％,and the drug-loading efficiency was (6.02 ± 0.27) ％.The in vitro release experiment showed that ultrasound can promote the release of doxorubicin in MPMBs.US imaging in vitro showed that the enhancement of MPMBs was better than PMBs,and MR imaging in vitro conformed that MPMBs could well enhance MR imaging.Conclusions The MPMBs is a multifunctional contrast agent with the treatment function as well as US/MR dual-mode imaging enhancement effect. Key words: Microbubbles ; Iron oxide ; Doxorubicin ; Polymer