OBJECTIVETo prepare a lymph node-targeted ultrasound/fluorescence bi-functional imaging contrast agents, and observe its effectiveness both on contrast-enhanced ultrasound (CEUS) and vivo near infrared fluorescence (NIR) imaging through animal experiments.

METHODSThe chimeric lymph node-targeted ligand (phosphatidylserine) and near-infrared fluorescent substance were assembled to form bi-functional contrast microbubbles. The morphology and size distribution were detected by optical microscope and Malvern potential tests. Five normal New Zealand white rabbits were subcutaneously injected with the prepared contrast agent in bilateral footpads, and the imaging effectiveness of lymph nodes and lymphatic vessel were observed by CEUS and NIR technique. Then blue dye was subcutaneously injected at the same site, and the rabbits were sacrificed for lymph nodes pathological examination.

RESULTSLipid ultrasound microbubbles,with a mean size of 3-5 Μm in diameter, appeared to be uniform in distribution and regular in configuration. The images of inflow lymphatic vessel and relevant lymph node were quickly showed up after the subcutaneous injection by CEUS, which was identical to the result detected by NIR. Biopsy confirmed that all the blue-stained lymph nodes could be displayed by NIR.

CONCLUSIONSThe self-made bi-functional contrast agent has a good imaging ability in CEUS and NIR imaging. It may be a better agent as lymph node tracer.

Animals ; Contrast Media ; chemistry ; Fluoresceins ; chemistry ; Lymph Nodes ; anatomy & histology ; diagnostic imaging ; Lymphatic Metastasis ; pathology ; Male ; Rabbits ; Ultrasonography

OBJECTIVETo prepare polyelectrolyte multilayer film-coated microbubble ultrasound contrast agent (UCA) and evaluate its effects in contrast imaging on normal rabbit's liver parenchyma.

METHODSPerfluorocarbon (PFC) -containing microbubble UCA (ST68-PFC) were prepared by sonication-based on surfactants (Span 60 and Tween 80). Subsequently, the resulting ST68-PFC microbubbles were coated using oppositely charged polylysine (PLL) and alginate (Alg) by microbubble-templated layer-by-layer self-assembly technique via electrostatic interaction. The enhancement effects in contrast imaging on normal rabbit's liver parenchyma were assessed.

RESULTSThe obtained microbubble UCA exhibited a narrow size distribution. The polyelectrolytes were successfully assembled onto the surface of ST68-PFC microbubbles. In vivo experiment showed that polyelectrolyte multilayer film-coated UCA effectively enhanced the imaging of rabbit's liver parenchyma.

CONCLUSIONSThe novel microbubble UCA obtained via layer-by-layer self-assembly, when enabling more functions, has no obvious difference in enhancement effects compared with the premodified microbubbles. The polymers with chemically active groups (such as amino group and carboxyl group) can be used as the outermost layer for the attachment of targeting ligands to microbubbles, which allows the selective targeting of the microbubbles to desired sites.

Alginates ; chemistry ; Animals ; Contrast Media ; administration & dosage ; chemistry ; Fluorocarbons ; chemistry ; Glucuronic Acid ; chemistry ; Hexuronic Acids ; chemistry ; Liver ; diagnostic imaging ; Microbubbles ; Polylysine ; chemistry ; Rabbits ; Ultrasonography

OBJECTIVETo prepare and characterize polyelectrolyte multilayer film coated microbubbles for use as ultrasound contrast agent (UCA) and evaluate its effects in ultrasonic imaging on normal rabbit's liver parenchyma.

METHODSPerfluorocarbon (PFC)-containing microbubbles (ST68-PFC) were prepared by sonication based on surfactant (Span 60 and Tween 80). Subsequently, the resulting ST68-PFC microbubbles were coated using oppositely charged polyelectrolytes by microbubble-templated layer-by-layer self-assembly technique via electrostatic interaction. The enhancement effects in ultrasonic imaging on normal rabbit's liver parenchyma were assessed.

RESULTSThe obtained microbubbles exhibited a narrow size distribution. The polyelectrolytes were successfully assembled onto the surface of ST68-PFC microbubbles. In vivo experiment showed that polyelectrolyte multilayer film coated UCA effectively enhanced the imaging of rabbit's liver parenchyma.

CONCLUSIONSThe novel microbubbles UCA coated with polyelectrolyte multilayer, when enabled more function, has no obvious difference in enhancement effects compared with the pre-modified microbubbles. The polymers with chemically active groups (such as amino group and carboxyl group) can be used as the outermost layer for attachment of targeting ligands onto microbubbles, allowing selective targeting of the microbubbles to combine with desired sites.

Animals ; Contrast Media ; chemistry ; Electrolytes ; chemistry ; Fluorocarbons ; chemistry ; Liver ; diagnostic imaging ; Microbubbles ; Polymers ; chemistry ; Rabbits ; Surface Properties ; Surface-Active Agents ; chemistry ; Ultrasonics ; Ultrasonography