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Find video protocols related to scientific articles indexed in Pubmed.
Injectable Smart Phase-Transformation Implants for Highly Efficient In Vivo Magnetic-Hyperthermia Regression of Tumors.
Adv. Mater. Weinheim
PUBLISHED: 08-28-2014
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A minimally invasive, highly efficient and versatile strategy is proposed for localized tumor regression by developing a smart injectable liquid-solid phase-transformation organic-inorganic hybrid composite material, i.e., magnetic Fe powder-dispersed PLGA (Fe/PLGA) implants formagnetic-hyperthermiatherapy of cancer.
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India ink incorporated multifunctional phase-transition nanodroplets for photoacoustic/ultrasound dual-modality imaging and photoacoustic effect based tumor therapy.
Theranostics
PUBLISHED: 08-01-2014
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The in vivo applications of gas-core microbubbles have been limited by gas diffusion, rapid body clearance, and poor vascular permeability. To overcome these limitations, using a modified three-step emulsion process, we have developed a first-of-its-kind India ink incorporated optically-triggerable phase-transition perfluorocarbon nanodroplets (INDs) that can provide not only three types of contrast mechanisms-conventional/thermoelastic photoacoustic, phase-transition/nonlinear photoacoustic, and ultrasound imaging contrasts, but also a new avenue for photoacoustic effect mediated tumor therapy. Upon pulsed laser illumination above a relatively low energy threshold, liquid-gas phase transition of the INDs has been demonstrated both in vitro and in vivo, offering excellent contrasts for photoacoustic and ultrasound dual-modality imaging. With further increased laser energy, the nanodroplets have been shown to be capable of destructing cancer cells in vivo, presumably due to the photoacoustic effect induced shock-wave generation from the carbon particles of the incorporated India ink. The demonstrated results suggest that the developed multifunctional phase-transition nanodroplets have a great potential for many theranostic biomedical applications, including photoacoustic/ultrasound dual-modality molecular imaging and targeted, localized cancer therapy.
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Evaluation of superparamagnetic iron oxide-polymer composite microcapsules for magnetic resonance-guided high-intensity focused ultrasound cancer surgery.
BMC Cancer
PUBLISHED: 04-11-2014
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Superparamagnetic poly (lactic-co-glycolic acid) (PLGA)-coated Fe3O4 microcapsules are receiving increased attention as potential diagnostic and therapeutic modalities in the field of oncology. In this study, PLGA-coated Fe3O4 microcapsules were combined with a magnetic resonance imaging-guided high-intensity focused ultrasound (MR-guided HIFU) platform, with the objective of investigating the effects of these composite microcapsules regarding MR-guided HIFU liver cancer surgery in vivo.
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Methotrexate-loaded PLGA nanobubbles for ultrasound imaging and Synergistic Targeted therapy of residual tumor during HIFU ablation.
Biomaterials
PUBLISHED: 01-29-2014
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High intensity focused ultrasound (HIFU) has attracted the great attention in tumor ablation due to its non-invasive, efficient and economic features. However, HIFU ablation has its intrinsic limitations for removing the residual tumor cells, thus the tumor recurrence and metastasis cannot be avoided in this case. Herein, we developed a multifunctional targeted poly(lactic-co-glycolic acid) (PLGA) nanobubbles (NBs), which not only function as an efficient ultrasound contrast agent for tumor imaging, but also a targeted anticancer drug carrier and excellent synergistic agent for enhancing the therapeutic efficiency of HIFU ablation. Methotrexate (MTX)-loaded NBs were synthesized and filled with perfluorocarbon gas subsequently using a facile but general double emulsion evaporation method. The active tumor-targeting monoclonal anti-HLA-G antibodies (mAbHLA-G) were further conjugated onto the surface of nanobubbles. The mAbHLA-G/MTX/PLGA NBs could enhance the ultrasound imaging both in vitro and in vivo, and the targeting efficiency to HLA-G overexpressing JEG-3 cells has been demonstrated. The elaborately designed mAbHLA-G/MTX/PLGA NBs can specifically target to the tumor cells both in vitro and in vivo, and their blood circulation time in vivo was much longer than non-targeted MTX/PLGA NBs. Further therapeutic evaluations showed that the targeted NBs as a synergistic agent can significantly improve the efficiency of HIFU ablation by changing the acoustic environment, and the focused ultrasound can promote the on-demand MTX release both in vitro and in vivo. The in vivo histopathology test and immunohistochemical analysis showed that the mAbHLA-G/MTX/PLGA NBs plus HIFU group presented most serious coagulative necrosis, the lowest proliferation index and the highest apoptotic index. Therefore, the successful introduction of targeted mAbHLA-G/MTX/PLGA NBs provides an excellent platform for the highly efficient, imaging-guided and non-invasive HIFU synergistic therapy of cancer with the supplementary functions of killing residual tumor cells and preventing tumor recurrence/metastasis.
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A simple route to prepare monodisperse Au NP-decorated, dye-doped, superparamagnetic nanocomposites for optical, MR, and CT trimodal imaging.
Small
PUBLISHED: 03-20-2013
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Monodisperse and uniform AuNP-decorated, dye-doped, superparamagnetic nanocomposites (Fe3 O4 @dye-hybrid@Au) are fabricated by using a simple method in which the Au NP formation and their attachment onto the core surface via S-Au covalent bonds proceeds almost simultaneously in a one-pot synthesis. The as-synthesized nanocomposites can simultaneously enhance the contrast effects for MR, CT, and cellular-sensitive optical imaging.
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Synergistic effects of ultrasound-targeted microbubble destruction and TAT peptide on gene transfection: an experimental study in vitro and in vivo.
J Control Release
PUBLISHED: 03-13-2013
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Cell-permeable peptides (CPPs) and ultrasound-targeted microbubble destruction (UTMD) have tremendous potential for gene delivery. However, their applications are limited due to nonspecificity of CPPs and low transfection efficiency of UTMD. Here, we developed a smart gene delivery system by encapsulating TAT peptide (TATp) and hepatocyte growth factor (HGF) gene within lipid microbubbles, in which TATp was protected from being enzymatically cleaved and HGF gene was protected from degradation. This new strategy had synergistic effects of UTMD and TATp on gene transfection. We investigated the efficacy and safety of HGF gene transfection mediated by the combination of UTMD and TATp in vitro and in vivo. The results from MTT assay and flow cytometry analyses indicated that the combination of UTMD and TATp could enhance HGF gene expression in HUVECs without any significant side effect on cell viability. In rat myocardial infarction models, we demonstrated that the protein and mRNA expressions of HGF in myocardium caused by the combination of UTMD and TATp were the highest. Histopathological findings demonstrated that the combination of UTMD and TATp enhanced myocardial microvasculature and ameliorated myocardial fibrosis. In conclusion, the combination of UTMD and TATp might be a safe and efficient technique for gene delivery.
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Facile synthesis of magnetite/perfluorocarbon co-loaded organic/inorganic hybrid vesicles for dual-modality ultrasound/magnetic resonance imaging and imaging-guided high-intensity focused ultrasound ablation.
Adv. Mater. Weinheim
PUBLISHED: 02-28-2013
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Multifunctional organic/inorganic hybrid nanovesicles, fabricated by a facile self-assembly/sol-gel approach, display a unique morphology (figure) and satisfactory stability under physiological conditions. By co-encapsulation of superparamagnetic magnetite nanoparticles and a liquid perfluorocarbon, the nanovesicles can be used not only as a dual-modality ultrasound/magnetic resonance contrast agent for accurate cancer diagnosis and monitoring, but also as a therapeutic enhancement agent for effective high-intensity focused ultrasound (HIFU) ablation.
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Microbubbles from gas-generating perfluorohexane nanoemulsions for targeted temperature-sensitive ultrasonography and synergistic HIFU ablation of tumors.
Adv. Mater. Weinheim
PUBLISHED: 02-03-2013
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A special "small to big" temperature-responsive phase-transformation strategy based on the "acoustic droplet vaporization (ADV)" mechanism is developed for efficient targeted ultrasonography and synergistic high intensity focused ultrasound (HIFU) cancer surgery by engineering targeted nanoemulsions, which is systematically evaluated and successfully demonstrated in vitro, ex vivo, and in vivo.
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Superparamagnetic perfluorooctylbromide nanoparticles as a multimodal contrast agent for US, MR, and CT imaging.
Acta Radiol
PUBLISHED: 01-14-2013
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Multimodal contrast agents usually containing two or more signal components can be used for several imaging modalities. Thus, complimentary information can be obtained by using just one kind of contrast agents.
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Diagnosis of digital clubbing by high-frequency ultrasound imaging.
Int. J. Dermatol.
PUBLISHED: 01-03-2013
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Current methods to diagnose clubbing have drawbacks. This study was done to test a novel and convenient method for the diagnosis of digital clubbing using high-frequency ultrasound.
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Preparation and characterization of gadolinium-loaded PLGA particles surface modified with RGDS for the detection of thrombus.
Int J Nanomedicine
PUBLISHED: 01-01-2013
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Thrombotic disease is a leading cause of death and disability worldwide. The development of magnetic resonance molecular imaging provides potential promise for early disease diagnosis. In this study, we explore the preparation and characterization of gadolinium (Gd)-loaded poly (lactic-co-glycolic acid) (PLGA) particles surface modified with the Arg-Gly-Asp-Ser (RGDS) peptide for the detection of thrombus. PLGA was employed as the carrier-delivery system, and a double emulsion solvent-evaporation method (water in oil in water) was used to prepare PLGA particles encapsulating the magnetic resonance contrast agent Gd diethylenetriaminepentaacetic acid (DTPA). To synthesize the Gd-PLGA/chitosan (CS)-RGDS particles, carbodiimide-mediated amide bond formation was used to graft the RGDS peptide to CS to form a CS-RGDS film that coated the surface of the PLGA particles. Blank PLGA, Gd-PLGA, and Gd-PLGA/CS particles were fabricated using the same water in oil in water method. Our results indicated that the RGDS peptide successfully coated the surface of the Gd-PLGA/CS-RGDS particles. The particles had a regular shape, smooth surface, relatively uniform size, and did not aggregate. The high electron density of the Gd-loaded particles and a translucent film around the particles coated with the CS and CS-RGDS films could be observed by transmission electron microscopy. In vitro experiments demonstrated that the Gd-PLGA/CS-RGDS particles could target thrombi and could be imaged using a clinical magnetic resonance scanner. Compared with the Gd-DTPA solution, the longitudinal relaxation time of the Gd-loaded particles was slightly longer, and as the Gd-load concentration increased, the longitudinal relaxation time values decreased. These results suggest the potential of the Gd-PLGA/CS-RGDS particles for the sensitive and specific detection of thrombus at the molecular level.
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Multifunctional mesoporous composite nanocapsules for highly efficient MRI-guided high-intensity focused ultrasound cancer surgery.
Angew. Chem. Int. Ed. Engl.
PUBLISHED: 09-01-2011
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Bloodless surgical knife: Nano-biotechnology has been introduced into imaging-guided high-intensity focused ultrasound (HIFU) cancer surgery by adopting engineered multifunctional manganese-based mesoporous composite nanocapsules as the contrast agents for T(1)-weighted magnetic resonance imaging (MRI) and simultaneously as synergistic agents for MRI-guided HIFU cancer surgery.
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Enhanced homing of mesenchymal stem cells to the ischemic myocardium by ultrasound-targeted microbubble destruction.
Ultrasonics
PUBLISHED: 06-06-2011
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In recent years, ultrasound-targeted microbubble destruction (UTMD) has been utilised for the targeted delivery of stem cells. We tested the effects of the myocardial micro-environment changes induced by UTMD on promoting the homing of mesenchymal stem cells (MSCs) to the ischemic myocardium. Dogs were randomly divided into two groups and treated with or without UTMD after the establishment of myocardial infarction models. 4,6-diamino-2-phenyl indole (DAPI) labelled MSCs were transplanted via coronary injections 2 weeks after myocardial infarction in both groups. The results from real-time PCR and western blot analyses indicated that the expression of various cytokines in UTMD-treated dogs was much higher than that observed in non-treated dogs. Histopathological findings demonstrate that ultrasound at a frequency of 1MHz and an intensity of 1.0W/cm(2) provoked inflammatory reactions with mild myocardial damage. Myocardial microenvironment changes caused by UTMD may promote the homing of MSCs to the ischemic myocardium. This non-invasive technique may be a promising method for cardiac cell transplantation therapy.
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Targeting an ultrasound contrast agent to folate receptors on ovarian cancer cells: feasibility research for ultrasonic molecular imaging of tumor cells.
J Ultrasound Med
PUBLISHED: 04-09-2010
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The purpose of the study was to synthesize and characterize folate-targeted microbubbles (MB(F)) as an ultrasound contrast agent and to evaluate their affinity to the folate receptor (FR) in vitro.
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Gd-DTPA-loaded PLGA microbubbles as both ultrasound contrast agent and MRI contrast agent--a feasibility research.
J. Biomed. Mater. Res. Part B Appl. Biomater.
PUBLISHED: 03-13-2010
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To prepare the Gd-DTPA-loaded poly (lactic-co-glycolic acid) (PLGA) microbubbles for both ultrasound imaging and MRI imaging.
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Ultrasound microbubbles enhance recombinant adeno-associated virus vector delivery to retinal ganglion cells in vivo.
Acad Radiol
PUBLISHED: 02-05-2010
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The aim of this study was to investigate whether ultrasound-mediated microbubble destruction enhances the transduction efficiency of recombinant adeno-associated virus (rAAV)-mediated enhanced green fluorescent protein (EGFP) gene into retinal ganglion cells (RGCs) of rats and whether it causes relevant adverse effects.
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A novel ultrasound microbubble carrying gene and Tat peptide: preparation and characterization.
Acad Radiol
PUBLISHED: 03-26-2009
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Ultrasound-targeted microbubble destruction is a promising technology for the targeted gene delivery. The purpose of the present study is to prepare a novel lipid ultrasound microbubble-carrying gene and transactivating transcriptional activator (Tat) peptide and to investigate its transfection effect in vivo.
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Doxorubicin loaded superparamagnetic PLGA-iron oxide multifunctional microbubbles for dual-mode US/MR imaging and therapy of metastasis in lymph nodes.
Biomaterials
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Current strategies for tumor-induced sentinel lymph node detection and metastasis therapy have limitations. In this work, we co-encapsulated iron oxide nanoparticles and chemotherapeutic drug into poly(lactic-co-glycolic acid) (PLGA) microbubbles to form multifunctional polymer microbubbles (MPMBs) for both tumor lymph node imaging and therapy. Fe(3)O(4) nanoparticles and doxorubicin (DOX) co-encapsulated PLGA microbubbles were prepared and filled with perfluorocarbon gas. Enhancement of ultrasound (US)/magnetic resonance (MR) imaging and US triggered drug delivery were evaluated both in vitro and in vivo. The MPMBs exhibited characters like narrow size distribution and smooth surface with a mean diameter of 868.0 ± 68.73 nm. In addition, varying the concentration of Fe(3)O(4) nanoparticles in the bubbles did not significantly influence the DOX encapsulation efficiency or drug loading efficiency. Our in vitro results demonstrated that these MPMBs could enhance both US and MR imaging which was further validated in vivo showing that these MPMBs enhanced tumor lymph nodes signals. The anti-tumor effect of MPMBs mediated chemotherapy was assessed in vivo using end markers like tumor proliferation index, micro blood vessel density and micro lymphatic vessel density, which were shown consistently the lowest after the MPMBs plus sonication treatment compared to controls. In line with these findings, the tumor cell apoptotic index was found the largest after the MPMBs plus sonication treatment. In conclusion, we have successfully developed a doxorubicin loaded superparamagnetic PLGA-Iron Oxide multifunctional theranostic agent for dual-mode US/MR Imaging of lymph node, and for low frequency US triggered therapy of metastasis in lymph nodes, which might provide a strategy for the imaging and chemotherapy of primary tumor and their metastases.
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Au-nanoparticle coated mesoporous silica nanocapsule-based multifunctional platform for ultrasound mediated imaging, cytoclasis and tumor ablation.
Biomaterials
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Au nanoparticles-coated, perfluorohexane-encapsulated and PEGylated mesoporous silica nanocapsule-based enhancement agents (MSNC@Au-PFH-PEG, abb. as MAPP) have been synthesized, for the ultrasound-induced cytoclasis, contrast-intensified ultrasound (US) imaging and US-guided high intensity focused ultrasound (HIFU) surgical therapy. Both the US-induced thermal effect and US triggered release of loaded model drug with MAPP under US exposure indicated the excellent US sensitivity of MAPP and its applicability for the combined chemo-/thermal therapy and future potential for HIFU ablation; US imaging under different modes verify the attractive US contrast intensification by using MAPP; US-guided HIFU therapy ex vivo and in vivo with MAPP is found to be highly efficient on rabbit VX2 xenograft tumor ablation due to the high thermal energy accumulation and increased mechanical/thermal effects from US-induced PFH bubble cavitations. MAPP can be promisingly used as an inorganic theranostic platform for contrast-intensified US imaging, combined chemotherapy and efficient HIFU tumor ablation under the guidance by the intensified US.
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The feasibility of using high frequency ultrasound to assess nerve ending neuropathy in patients with diabetic foot.
Eur J Radiol
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The nerve ending problem is one of the major causes for diabetic feet. In this work, we explored the feasibilities of using high frequency ultrasound (US) in nerve ending problem evaluation for patients with diabetic foot.
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Direct and Doppler angle-independent measurement of blood flow velocity in small-diameter vessels using ultrasound microbubbles.
Clin Imaging
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This article represents an initial attempt to demonstrate the feasibility of a novel method for measuring flow velocity in small vessels, which is a direct, noninvasive, ultrasound-guided, and Doppler angle-independent method. In vitro, experiments were designed to mimic blood flow inside tubes. Harmonic ultrasound imaging was used to track the movement of microbubbles, and the mean flow velocity was calculated. In vivo, the flow velocities were measured in the central arteries of rabbit ears. This method can be used whenever the Doppler ultrasound cannot measure the velocity in small vessels because of either low sensitivity or Doppler angle limitation.
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Ultrasound triggered drug release from 10-hydroxycamptothecin-loaded phospholipid microbubbles for targeted tumor therapy in mice.
J Control Release
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Ultrasound targeted microbubble destruction (UTMD) was one of the most promising strategies to enhance drug delivery in cancer therapy. Microbubbles (MBs) serve as a vehicle to carry anti-tumor drugs and locally release them when exposed to therapeutic ultrasound, resulting in drug accumulation in tumor tissues and enhanced anti-tumor effect. However the ultrasound triggered drug delivery system has been seriously limited due to the poor loading capacity of MBs. Here we present a new strategy to overcome the low drug payload of MBs for ultrasound guided drug delivery. In this study, we developed a novel microbubble carrying 10-HCPT which only needs a particularly low single dose of injection (4-6 mg) for tumor therapy in clinical application, therefore, the required high dosing of drug loaded MBs for ultrasound mediated drug delivery is not necessary. We subsequently investigated the combination of ultrasound application with HLMs to achieve therapeutic effect on tumor at a feasible dose of MBs. HLMs were manufactured with a high drug encapsulation and loading content and simultaneously maintained the acoustic properties as an ultrasound contrast agent. After that, tumor-bearing mice were routinely and non-invasively administered with HLMs through the tail vein and were then exposed to ultrasound, resulting in a remarkable drug accumulation in tumor tissues and a significant increase in tumor inhibition rate (70.6%) compared with HLMs alone (47.8%) as well as commercial HCPT injection (49.4). In conclusion, HLMs are expected to improve the therapeutic efficacy of MBs and are worthy of further study for UTMD mediated drug delivery.
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Manganese oxide-based multifunctionalized mesoporous silica nanoparticles for pH-responsive MRI, ultrasonography and circumvention of MDR in cancer cells.
Biomaterials
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Nano-biotechnology has been introduced into cancer theranostics by engineering a new generation of highly versatile hybrid mesoporous composite nanocapsules (HMCNs) for manganese-based pH-responsive dynamic T(1)-weighted magnetic resonance imaging (MRI) to efficiently respond and detect the tumor acidic microenvironment, which was further integrated with ultrasonographic function based on the intrinsic unique hollow nanostructures of HMCNs for potentially in vitro and in vivo dual-modality cancer imaging. The manganese oxide-based multifunctionalization of hollow mesoporous silica nanoparticles was achieved by an in situ redox reaction using mesopores as the nanoreactors. Due to the dissolution nature of manganese oxide nanoparticles under weak acidic conditions, the relaxation rate r(1) of manganese-based mesoporous MRI-T(1) contrast agents (CAs) could reach 8.81 mM(-1)s(-1), which is a 11-fold magnitude increase compared to the neutral condition, and is almost two times higher than commercial Gd(III)-based complex agents. This is also the highest r(1) value ever reported for manganese oxide nanoparticles-based MRI-T(1) CAs. In addition, the hollow interiors and thin mesoporous silica shells endow HMCNs with the functions of CAs for efficient in vitro and in vivo ultrasonography under both harmonic- and B-modes. Importantly, the well-defined mesopores and large hollow interiors of HMCNs could encapsulate and deliver anticancer agents (doxorubicin) intracellularly to circumvent the multidrug resistance (MDR) of cancer cells and restore the anti-proliferative effect of drugs by nanoparticle-mediated endocytosis process, intracellular drug release and P-gp inhibition/ATP depletion in cancer cells.
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Superparamagnetic PLGA-iron oxide microcapsules for dual-modality US/MR imaging and high intensity focused US breast cancer ablation.
Biomaterials
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Organic/inorganic, hybrid, multifunctional, material-based platforms combine the merits of diverse functionalities of inorganic nanoparticles and the excellent biocompatibility of organic systems. In this work, superparamagnetic poly(lactic-co-glycolic acid) (PLGA) microcapsules (Fe(3)O(4)/PLGA) have been developed, as a proof-of-concept, for the application in ultrasound/magnetic resonance dual-modality biological imaging and enhancing the therapeutic efficiency of high intensity focused ultrasound (HIFU) breast cancer surgery in vitro and in vivo. Hydrophobic Fe(3)O(4) nanoparticles were successfully integrated into PLGA microcapsules by a typical double emulsion evaporation process. In this process, highly dispersed superparamagnetic Fe(3)O(4)/PLGA composite microcapsules with well-defined spherical morphology were obtained with an average diameter of 885.6 nm. The potential of these microcapsules as dual contrast agents for ultrasonography and magnetic resonance imaging were demonstrated in vitro and, also, preliminarily in vivo. Meanwhile, the prepared superparamagnetic composite microcapsules were administrated into rabbits bearing breast cancer model for the evaluation of the in vivo HIFU synergistic ablation efficiency caused by the introduction of such microcapsules. Our results showed that the employment of the composite microcapsules could efficiently enhance ultrasound imaging of cancer, and greatly enhance the HIFU ablation of breast cancer in rabbits. In addition, pathological examination was systematically performed to detect the structural changes of the target tissue caused by HIFU ablation. This finding demonstrated that successful introduction of these superparamagnetic microcapsules into HIFU cancer surgery provided an alternative strategy for the highly efficient imaging-guided non-invasive HIFU synergistic therapy of cancer.
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Poly(Lactide-co-glycolide) ultrasonographic microbubbles carrying Sudan black for preoperative and intraoperative localization of lymph nodes.
Clin. Breast Cancer
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Lymph node (LN) examination plays a critical role in the staging and treatment of several kinds of cancer such as lesions of the breast. However current strategies have limitations. This study aimed to develop a novel imaging agent, a polymeric ultrasonographic contrast agent carrying Sudan black (SB), for ultrasonographic imaging of the regional LNs before surgery and to directly localize the LNs during surgery. The poly(lactide-co-glycolide) (PLGA) ultrasonographic microbubbles carrying Sudan black B (SB) (SB-PLGA microbubbles) were prepared by the double emulsion method. The SB-PLGA microbubbles had a diameter of 1.5 ± 0.5 ?m and the SB encapsulation efficiency was (86.2 ± 1.56%). Results from MTT assays suggested that these bubbles have little cytotoxicity to mouse macrophages after incubation. Confocal laser scanning microscopy showed that the PLGA microbubbles carrying the fluorescent dye rhodamine 6G were taken up by macrophages after 2-hour incubation. In addition, these SB-PLGA microbubbles were able to enhance ultrasonographic contrast of 12 popliteal LNs of 6 rabbits. Furthermore, the LNs were easily identifiable by the naked eye during surgery because of the blue color of the SB-PLGA microbubbles inside the LNs. By cryosectioning and hematoxylin and eosin (H&E) staining of LN tissue, our results showed that these SB-PLGA microbubbles were internalized inside the macrophages of the LNs. To conclude, the SB-PLGA microbubbles could be a suitable imaging agent for preoperative and intraoperative localization of LNs as well as for a preoperative ultrasonographically guided core needle biopsy of suspicious sentinel lymph nodes (SLNs) in cancer patients, hence enhancing treatment outcome.
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Hematoporphyrin encapsulated PLGA microbubble for contrast enhanced ultrasound imaging and sonodynamic therapy.
J Microencapsul
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The purpose of this study was to develop a sonosensitizer-loaded multi-functional ultrasound (US) contrast agent for both tumour therapy and imaging. The hematoporphyrin (HP)-encapsulated poly(lactic-co-glycolic acid) microbubbles (HP-PLGA-MBs) were prepared and filled with perfluorocarbon gases. The enhancement of US imaging and its sonodynamically induced anti-tumour effect were evaluated by both in vitro and in vivo experiments. The HP-PLGA-MBs have a narrow size distribution and smooth surface with a mean diameter of 702.6?±?56.8?nm and HP encapsulation efficiency of 63.50?±?1.26% and drug-loading efficiency of 2.15?±?0.13%. The HP-PLGA-MBs could well enhance the ultrasound imaging both in vitro and in vivo. A significant anti-tumour effect was obtained by HP-PLGA-MBs mediated sonodynamic therapy. The tumour growth rate and the tumour proliferation index were the lowest in the HP-PLGA-MBs plus sonication group. And the tumour cell apoptotic index was the biggest in the HP-PLGA-MBs plus sonication group. In conclusion, a sonosensitizer-loaded multi-functional contrast agent was constructed and the feasibility was demonstrated, which might provide a novel strategy for tumour imaging and therapy.
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Differentiation of benign periablational enhancement from residual tumor following radio-frequency ablation using contrast-enhanced ultrasonography in a rat subcutaneous colon cancer model.
Ultrasound Med Biol
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Benign periablational enhancement (BPE) response to thermal injury is a barrier to early detection of residual tumor in contrast enhanced imaging after radio-frequency (RF) ablation. The objective of this study was to evaluate the role of quantitative of contrast-enhanced ultrasound (CEUS) in early differentiation of BPE from residual tumor in a BD-IX rat subcutaneous colon cancer model. A phantom study was first performed to test the validity of the perfusion parameters in predicting blood flow of two US contrast imaging modes-contrast harmonic imaging (CHI) and microflow imaging (MFI). To create a simple model of BPE, a peripheral portion of the tumor was ablated along with surrounding normal tissue, leaving part of the tumor untreated. First-pass dynamic enhancement (FPDE) and MFI scans of CEUS were performed before ablation and immediately, 1, 4 and 7 days after ablation. Time-intensity-curves in regions of BPE and residual tumor were fitted to the function y = A(1-exp[-?{t-t0}])+C, in which A, ?, t0 and C represent blood volume, flow speed, time to start and baseline intensity, respectively. In the phantom study, positive linear correlations were noted between A, ?, A? and contrast concentration, speed and flow rate, respectively, in both CHI and MFI. On CEUS images of the in vivo study, the unenhanced ablated zone was surrounded by BPE and irregular peripheral enhancement consistent with residual tumor. On days 0, 4 and 7, blood volume (A) in BPE was significantly higher than that in residual tumor in both FPDE imaging and MFI. Significantly greater blood flow (A?) was seen in BPE compared with residual tumor tissue in FPDE on day 7 and in MFI on day 4. The results of this study demonstrate that qualitative CEUS can be potentially used for early detection of viable tumor in post-ablation assessment.
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What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.