Preparation and ultrasonic imaging of PFOB-Ioaded polymeric nanomicelle and nanovesicle

Abstract

Objective To formed ranoscale ultrasound contrast agents loading PFOB by selfassembly of amphiphilic block copolymer for ultrasonic imaging in vivo and in vitro.Methods The biodegradable copolymer-poly(ethylene glycol)-b-poly (D, L-lactic acid) (PEG-PDLLA) self-assembled to form PFOB-loaded nanomicelle and nanovesicle with different PFOB concentration by solvent volatilization.The configuration and particle-sizing of resulting nanoparticles was determined,and their ultrasonic imaging in vitro and contrast-enhanced ultrasonography on subcutaneous tissue by focal injection in vivo were observed.Results In transmission electron microscope images, these micelles and vesicles appeared uniformly spherical with smooth surface.All the size distributions were narrow and mean diameters were from 404.3 to 475.8 nm using laser particle-sizing analyzer.In vitro and in vivo experiment showed that,the higher PFOB concentration, the more remarkable effect of ultrasound imaging.Especially, nanovesilces'ultrasonography effect was much better than nanomicelles' under same conditions.Conclusions PFOB-loaded nano-micelles and nano-vesicles prepared by solvent volatilization and self-assembly of PEG-PDLLA can obviously enhance ultrasound contrast and nanovesicle behaves better than nano-micelle. Key words: Ultrasonography; Microbubbles ; Nanotechnology