Fabrication of PFC core hybrid shell micro bubbles and its evaluation as ultrasound contrast agents

Abstract

Microbubbles have widely been used as ultrasound contrast agents in clinical diagnosis and hold great potential for ultrasound mediated therapy. However, instability (La place pressure and short half-life) of the MB still limit their application in imaging and therapy. To tackle this problem, stabilized Lecithin and PCL micro-bubbles consisting of Perfluorooctane core were synthesized by thin film hydration method and solvent evaporation technique, respectively. FTIR and SEM analysis indicated the formation of microbubbles .Clinical ultrasound scanner was used to scatter and induce phase transition of liquid perfluorooctane into gas by acoustic droplet vaporization for in-vitro studies using 3.5 Mhz, 8.6Mhz and 10Mhz frequency transducers at 0.4-1.4 mechanical index. An enhanced mean gray scale intensity of 44.89db was observed for Lecithin MB at 0.4 MI,10 Mhz as compared to PCL MB. Cytotoxicity of the microbubbles was assessed by MTT assay proving their good biocompatibility. The results showed improved backscatter and echogenicity. The study shows the potential use of these constructs as ultrasound contrast agents.