New Span-PEG-composited FeO-CNT as a multifunctional ultrasound contrast agent for inflammation and thrombotic niduses.

By attaching ferroferric oxide (FeO) to drug-carrying carbon nanotubes (CNTs), we generated a new Span-PEG composite with FeO-CNT multifunctional microbubbles for inflammation and thrombus niduses. The FeO-CNT magnetic targeting complex was prepared by synthesis, and then acetylsalicylic acid (ASA) and gentamicin (GM) were loaded onto the FeO-CNT complex by physical methods to produce FeO-CNT-ASA and FeO-CNT-GM complexes, respectively. Span-PEG-composited FeO-CNT-ASA or FeO-CNT-GM microbubbles were synthesized with Span and PEG as the membrane materials by the acoustic cavitation method. The obtained composite microbubbles were smooth, hollow spheres with an average particle size of 425 nm. The ASA and GM loading rates in Span-PEG-composited FeO-CNT-ASA and FeO-CNT-GM microbubbles were 1.12% and 19.05%, respectively. Span-PEG-composited FeO-CNT-ASA microbubbles inhibited thrombosis and demonstrated an anticoagulation effect . Additionally, Span-PEG-composited FeO-CNT-ASA microbubbles showed significantly enhanced ultrasound imaging of rabbit abdominal aorta and extended the signal time under the action of an external magnetic field. Thus, Span-PEG-composited FeO-CNT-GM microbubbles inhibited and , enhanced the ultrasound imaging of rabbit abdominal uterus and had better stability and fluidity.