New Span-PEG-composited Fe(3)O(4)-CNT as a multifunctional ultrasound contrast agent for inflammation and thrombotic niduses

By attaching ferroferric oxide (Fe(3)O(4)) to drug-carrying carbon nanotubes (CNTs), we generated a new Span-PEG composite with Fe(3)O(4)-CNT multifunctional microbubbles for inflammation and thrombus niduses. The Fe(3)O(4)-CNT magnetic targeting complex was prepared by in situ synthesis, and then acetylsalicylic acid (ASA) and gentamicin (GM) were loaded onto the Fe(3)O(4)-CNT complex by physical methods to produce Fe(3)O(4)-CNT-ASA and Fe(3)O(4)-CNT-GM complexes, respectively. Span-PEG-composited Fe(3)O(4)-CNT-ASA or Fe(3)O(4)-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 Fe(3)O(4)-CNT-ASA and Fe(3)O(4)-CNT-GM microbubbles were 1.12% and 19.05%, respectively. Span-PEG-composited Fe(3)O(4)-CNT-ASA microbubbles inhibited thrombosis and demonstrated an anticoagulation effect in vitro. Additionally, Span-PEG-composited Fe(3)O(4)-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 Fe(3)O(4)-CNT-GM microbubbles inhibited Escherichia coli and Staphylococcus aureus, enhanced the ultrasound imaging of rabbit abdominal uterus and had better stability and fluidity.