Applications of sub-micron low-boiling point phase change contrast agents for ultrasound imaging and therapy

Monodisperse magnetic lecithin-PFP submicron bubbles as dual imaging contrast agents for ultrasound (US) and MRI

“…Briey, 100 mg of soy-lecithin and 20 mg of cholesterol were dissolved in 10 ml of chloroform. Six concentrations (5,10,20,30,40, 50 mg ml À1 of SPIONs in chloroform) were made and added dropwise into the above lipid solution and stirred at room temperature for 30 minutes followed by rotary evaporation at 40 C under vacuum to generate lipid lm which was then dried for 2 hours under vacuum. The thin lm was hydrated with 10 ml PBS (pH 7) and was heated above the transition temperature of phospholipid (T m ¼ 50 C) to form liposomes.…”

“…SPIONs have a unique capacity to reduce spin–spin relaxation time thus reducing signal intensity producing a darker image. 5 The effect of SPIONs on transverse relaxation times doesn't prevent its use on T1 relaxation and can be used to achieve both T1 and T2 weighted images if the sequences are chosen properly. 6 …”

“…Compared to gaseous core, the perflurocarbons (PFCs) have poor solubility in both water and blood, are inert, low surface tension and have good compatibility. 4 Among liquid PFCs, perfluoropentane (PFP) was chosen as core material which when exposed to suitable temperature and acoustic pressure undergoes phase transition 5 …”

“…SPIONs have a unique capacity to reduce spin-spin relaxation time thus reducing signal intensity producing a darker image. 5 The effect of SPIONs on transverse relaxation times doesn't prevent its use on T1 relaxation and can be used to achieve both T1 and T2 weighted images if the sequences are chosen properly. 6 Liposomes owing to properties like biocompatible nature, lessened toxicity concerns, the multifunctional surface can serve as a theranostic platform that supports multimodal imaging.…”

“…Compared to gaseous core, the perurocarbons (PFCs) have poor solubility in both water and blood, are inert, low surface tension and have good compatibility. 4 Among liquid PFCs, peruoropentane (PFP) was chosen as core material which when exposed to suitable temperature and acoustic pressure undergoes phase transition 5 The current paper is focused on the preparation of magnetic lecithin microbubbles with peruoropentane (PFP) as core and their use in bimodal US/MR imaging. The synthesis route opted for iron oxide nanoparticles was co-precipitation and SPIONs were stabilized by oleic acid and incorporated in lecithin microbubbles using thin-lm hydration.…”