A device for continuous infusion of microbubbles (MBs) 'Infucon' has been designed, constructed and tested on rabbits. The device prevents MBs from flotation and accumulation in the layer directly below the surface in the syringe injection during i.v. application. Homogenous i.v. application of MBs was tested on 16 male New Zealand White rabbits (average weight about 3.5 kg). Two sorts of MBs were used - a set of commercial SonoVue diagnostic microbubbles (Bracco) and pegylated DPPC microbubbles (PegMBs), which had been prepared in our laboratory. Sulphur hexafluoride was used as a filling gas. The application of MBs by continuous infusion via Infucon prolonged the ultrasound signal period in the heart of the rabbit to 12 min in comparison to about 1 min observed in bolus application. No adverse effects were observed on the tested rabbits after the MB application via Infucon. The principle employed in the prototype device Infucon could be used for development of the device intended for clinical applications.

• MeSH
• 1,2-dipalmitoylfosfatidylcholin chemie   MeSH
• časové faktory MeSH
• fluorid sírový diagnostické užití   MeSH
• fosfolipidy diagnostické užití   MeSH
• intravenózní infuze MeSH
• králíci MeSH
• mikrobubliny diagnostické užití   MeSH
• polyethylenglykoly chemie   MeSH
• ultrasonografie metody   MeSH
• zvířata MeSH
• Check Tag
• králíci MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH

Identifying intended or accidental cellular targets for drug delivery systems is highly relevant for evaluating therapeutic and toxic effects. However, limited knowledge exists on the distribution of nano- and micrometer-sized carrier systems at the cellular level in different organs. We hypothesized that clinically relevant carrier materials, differing in composition and size, are able to target distinct myeloid cell subsets that control inflammatory processes, such as macrophages, neutrophils, monocytes and dendritic cells. Therefore, we analyzed the biodistribution and in vivo cellular uptake of intravenously injected poly(N-(2-hydroxypropyl) methacrylamide) polymers, PEGylated liposomes and poly(butyl cyanoacrylate) microbubbles in mice, using whole-body imaging (computed tomography - fluorescence-mediated tomography), intra-organ imaging (intravital multi-photon microscopy) and cellular analysis (flow cytometry of blood, liver, spleen, lung and kidney). While the three carrier materials shared accumulation in tissue macrophages in liver and spleen, they notably differed in uptake by other myeloid subsets. Kupffer cells and splenic red pulp macrophages rapidly take up microbubbles. Liposomes efficiently reach dendritic cells in liver, lung and kidney. Polymers exhibit the longest circulation half-life and target endothelial cells in the liver, neutrophils and alveolar macrophages. The identification of such previously unrecognized target cell populations might open up new avenues for more efficient drug delivery.

• MeSH
• cílená molekulární terapie metody   MeSH
• liposomy chemie   MeSH
• mikrobubliny terapeutické užití   MeSH
• myeloidní buňky chemie   cytologie   MeSH
• myši nahé MeSH
• myši MeSH
• nanokapsle aplikace a dávkování   chemie   MeSH
• orgánová specificita MeSH
• polymery chemie   MeSH
• testování materiálů MeSH
• tkáňová distribuce MeSH
• tobolky aplikace a dávkování   chemie   MeSH
• vnitřnosti chemie   cytologie   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Specific contrast ultrasound is widely applied in diagnostic procedures on humans but remains underused in veterinary medicine. The objective of this study was to evaluate the use of microbubble-based contrast for rapid ultrasonographic diagnosis of thrombosis in small animals, using male New Zealand white rabbits (average weight about 3.5 kg) as a model. It was hypothesized that the use of microbubble-based contrast agents will result in a faster and more precise diagnosis in our model of thrombosis. A pro-coagulant environment had been previously established by combining endothelial denudation and external vessel wall damage. Visualization of thrombi was achieved by application of contrast microbubbles [sterically stabilized, phospholipid-based microbubbles filled with sulfur hexafluoride (SF6) gas] and ultrasonography. As a result, rapid and clear diagnosis of thrombi in aorta abdominalis was achieved within 10 to 30 s (mean: 17.3 s) by applying microbubbles as an ultrasound contrast medium. In the control group, diagnosis was not possible or took 90 to 180 s. Therefore, sterically stabilized microbubbles were found to be a suitable contrast agent for the rapid diagnosis of thrombi in an experimental model in rabbits. This contrast agent could be of practical importance in small animal practice for rapid diagnosis of thrombosis.

• MeSH
• aorta abdominalis patologie   ultrasonografie   MeSH
• fluorid sírový diagnostické užití   MeSH
• kočky MeSH
• kontrastní látky diagnostické užití   MeSH
• králíci MeSH
• mikrobubliny diagnostické užití   veterinární   MeSH
• modely nemocí na zvířatech MeSH
• nemoci koček patologie   ultrasonografie   MeSH
• neparametrická statistika MeSH
• tromboembolie patologie   ultrasonografie   veterinární   MeSH
• ultrasonografie dopplerovská metody   veterinární   MeSH
• zvířata MeSH
• Check Tag
• kočky MeSH
• králíci MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Drug delivery to central nervous pathologies is compromised by the blood-brain barrier (BBB). A clinically explored strategy to promote drug delivery across the BBB is sonopermeation, which relies on the combined use of ultrasound (US) and microbubbles (MB) to induce temporally and spatially controlled opening of the BBB. We developed an advanced in vitro BBB model to study the impact of sonopermeation on the delivery of the prototypic polymeric drug carrier pHPMA as a larger molecule and the small molecule antiviral drug ribavirin. This was done under standard and under inflammatory conditions, employing both untargeted and RGD peptide-coated MB. The BBB model is based on human cerebral capillary endothelial cells and human placental pericytes, which are co-cultivated in transwell inserts and which present with proper transendothelial electrical resistance (TEER). Sonopermeation induced a significant decrease in TEER values and facilitated the trans-BBB delivery of fluorescently labeled pHPMA (Atto488-pHPMA). To study drug delivery under inflamed endothelial conditions, which are typical for e.g. tumors, neurodegenerative diseases and CNS infections, tumor necrosis factor (TNF) was employed to induce inflammation in the BBB model. RGD-coated MB bound to and permeabilized the inflamed endothelium-pericyte co-culture model, and potently improved Atto488-pHPMA and ribavirin delivery. Taken together, our work combines in vitro BBB bioengineering with MB-mediated drug delivery enhancement, thereby providing a framework for future studies on optimization of US-mediated drug delivery to the brain.

• MeSH
• antivirové látky aplikace a dávkování   chemie   farmakologie   farmakokinetika   MeSH
• endoteliální buňky * účinky léků   metabolismus   MeSH
• hematoencefalická bariéra * metabolismus   MeSH
• kokultivační techniky * MeSH
• lékové transportní systémy metody   MeSH
• lidé MeSH
• mikrobubliny * MeSH
• oligopeptidy * chemie   aplikace a dávkování   farmakokinetika   MeSH
• pericyty * metabolismus   účinky léků   MeSH
• polymery chemie   aplikace a dávkování   MeSH
• ribavirin aplikace a dávkování   chemie   farmakokinetika   MeSH
• ultrazvukové vlny MeSH
• zánět farmakoterapie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

• MeSH
• lidé MeSH
• mikrobubliny využití   MeSH
• sérový albumin aplikace a dávkování   diagnostické užití   MeSH
• skleroterapie metody   využití   MeSH
• tetradecylsíran sodný aplikace a dávkování   terapeutické užití   MeSH
• vena saphena účinky léků   MeSH
• žilní insuficience terapie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• kongresy MeSH

Widely used classical angiography with the use of iodine contrast agents is highly problematic, particularly in patients with diabetes mellitus, cardiac and pulmonary diseases, or degree III or IV renal insufficiency. Some patients may be susceptible to allergic reaction to the iodine contrast substance. The intravenous injection of a bolus of CO2 (negative contrast) is an alternative method, which is, however, currently only used for imaging blood vessels of the lower limbs. The aim of our project was to design and test on an animal model a methodology for injecting the CO2 foam which would minimize the possibility of embolization of the brain tissue and heart infarction, leading to their damage. This is important research for the further promotion of the use of CO2, which is increasingly important for endovascular diagnosis and treatment, because carbon-dioxide-related complications are extremely rare. CO2 foam was prepared by the rapid mixing in a 2:1 ratio of CO2 and fetal bovine serum (FBS)-enriched Dulbecco's Modified Eagle Medium (DMEM). Freshly prepared CO2 foam was administered into the catheterized rat tail vein or cannulated rat abdominal aorta and inferior vena cava (IVC). CO2 foam was compared with commercially available microbubbles (lipid shell/gas core). The rat heart in its parasternal long axis was imaged in B-Mode and Non-linear Contrast Mode before/during and after the contrast administration. Samples of the brain, heart and lungs were collected and subjected to histological examination. The non-linear contrast imaging method enables the imaging of micron-sized gas microbubbles inside a rat heart. The significantly shorter lifetime of the prepared CO2 foam is a benefit for avoiding the local ischemia of tissues.

• MeSH
• angiografie MeSH
• jod * MeSH
• kontrastní látky MeSH
• krysa rodu rattus MeSH
• mikrobubliny MeSH
• oxid uhličitý * škodlivé účinky   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Myeloid immune cells promote inflammation and fibrosis in chronic liver diseases. Drug delivery systems, such as polymers, liposomes and microbubbles, efficiently target myeloid cells in healthy liver, but their targeting properties in hepatic fibrosis remain elusive. We therefore studied the biodistribution of three intravenously injected carrier material, i.e. 10 nm poly(N-(2-hydroxypropyl)methacrylamide) polymers, 100 nm PEGylated liposomes and 2000 nm poly(butyl cyanoacrylate) microbubbles, in two fibrosis models in immunocompetent mice. While whole-body imaging confirmed preferential hepatic uptake even after induction of liver fibrosis, flow cytometry and immunofluorescence analysis revealed markedly decreased carrier uptake by liver macrophage subsets in fibrosis, particularly for microbubbles and polymers. Importantly, carrier uptake co-localized with immune infiltrates in fibrotic livers, corroborating the intrinsic ability of the carriers to target myeloid cells in areas of inflammation. Of the tested carrier systems liposomes had the highest uptake efficiency among hepatic myeloid cells, but the lowest specificity for cellular subsets. Hepatic fibrosis affected carrier uptake in liver and partially in spleen, but not in other tissues (blood, bone marrow, lung, kidney). In conclusion, while drug carrier systems target distinct myeloid cell populations in diseased and healthy livers, hepatic fibrosis profoundly affects their targeting efficiency, supporting the need to adapt nanomedicine-based approaches in chronic liver disease.

• MeSH
• fluorescenční mikroskopie MeSH
• imunohistochemie MeSH
• jaterní cirhóza metabolismus   MeSH
• lékové transportní systémy MeSH
• liposomy chemie   MeSH
• lymfocyty metabolismus   MeSH
• makrofágy metabolismus   MeSH
• mikrobubliny MeSH
• myši MeSH
• nanomedicína MeSH
• polymery chemie   MeSH
• průtoková cytometrie MeSH
• rentgenová mikrotomografie MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Rationale: The blood-brain barrier (BBB) is a major obstacle for drug delivery to the brain. Sonopermeation, which relies on the combination of ultrasound and microbubbles, has emerged as a powerful tool to permeate the BBB, enabling the extravasation of drugs and drug delivery systems (DDS) to and into the central nervous system (CNS). When aiming to improve the treatment of high medical need brain disorders, it is important to systematically study nanomedicine translocation across the sonopermeated BBB. To this end, we here employed multimodal and multiscale optical imaging to investigate the impact of DDS size on brain accumulation, extravasation and penetration upon sonopermeation. Methods: Two prototypic DDS, i.e. 10 nm-sized pHPMA polymers and 100 nm-sized PEGylated liposomes, were labeled with fluorophores and intravenously injected in healthy CD-1 nude mice. Upon sonopermeation, computed tomography-fluorescence molecular tomography, fluorescence reflectance imaging, fluorescence microscopy, confocal microscopy and stimulated emission depletion nanoscopy were used to study the effect of DDS size on their translocation across the BBB. Results: Sonopermeation treatment enabled safe and efficient opening of the BBB, which was confirmed by staining extravasated endogenous IgG. No micro-hemorrhages, edema and necrosis were detected in H&E stainings. Multimodal and multiscale optical imaging showed that sonopermeation promoted the accumulation of nanocarriers in mouse brains, and that 10 nm-sized polymeric DDS accumulated more strongly and penetrated deeper into the brain than 100 nm-sized liposomes. Conclusions: BBB opening via sonopermeation enables safe and efficient delivery of nanomedicine formulations to and into the brain. When looking at accumulation and penetration (and when neglecting issues such as drug loading capacity and therapeutic efficacy) smaller-sized DDS are found to be more suitable for drug delivery across the BBB than larger-sized DDS. These findings are valuable for better understanding and further developing nanomedicine-based strategies for the treatment of CNS disorders.

• MeSH
• fluorescenční barviva aplikace a dávkování   MeSH
• hematoencefalická bariéra diagnostické zobrazování   metabolismus   MeSH
• lékové transportní systémy metody   MeSH
• liposomy aplikace a dávkování   MeSH
• mikrobubliny MeSH
• mozek diagnostické zobrazování   MeSH
• myši nahé MeSH
• myši MeSH
• nanomedicína metody   MeSH
• nemoci mozku farmakoterapie   MeSH
• optické zobrazování metody   MeSH
• ultrasonografie metody   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

• MeSH
• diagnostické techniky urologické přístrojové vybavení   využití   MeSH
• kontrastní látky chemická syntéza   MeSH
• lidé MeSH
• mikrobubliny trendy   využití   MeSH
• nádory ledvin ultrasonografie   MeSH
• Check Tag
• lidé MeSH

BACKGROUND: Oncolytic viruses are among the most powerful and selective cancer therapeutics under development and are showing robust activity in clinical trials, particularly when administered directly into tumor nodules. However, their intravenous administration to treat metastatic disease has been stymied by unfavorable pharmacokinetics and inefficient accumulation in and penetration through tumors. METHODS: Adenovirus (Ad) was "stealthed" with a new N-(2-hydroxypropyl)methacrylamide polymer, and circulation kinetics were characterized in Balb/C SCID mice (n = 8 per group) bearing human ZR-75-1 xenograft tumors. Then, to noninvasively increase extravasation of the circulating polymer-coated Ad into the tumor, it was coinjected with gas microbubbles and the tumor was exposed to 0.5 MHz focused ultrasound at peak rarefactional pressure of 1.2 MPa. These ultrasound exposure conditions were designed to trigger inertial cavitation, an acoustic phenomenon that produces shock waves and can be remotely monitored in real-time. Groups were compared with Student t test or one-way analysis of variance with Tukey correction where groups were greater than two. All statistical tests were two-sided. RESULTS: Polymer-coating of Ad reduced hepatic sequestration, infection (>8000-fold; P < .001), and toxicity and improved circulation half-life (>50-fold; P = .001). Combination of polymer-coated Ad, gas bubbles, and focused ultrasound enhanced tumor infection >30-fold; (4 × 10(6) photons/sec/cm(2); standard deviation = 3 × 10(6) with ultrasound vs 1.3 × 10(5); standard deviation = 1 × 10(5) without ultrasound; P = .03) and penetration, enabling kill of cells more than 100 microns from the nearest blood vessel. This led to substantial and statistically significant retardation of tumor growth and increased survival. CONCLUSIONS: Combining drug stealthing and ultrasound-induced cavitation may ultimately enhance the efficacy of a range of powerful therapeutics, thereby improving the treatment of metastatic cancer.

• MeSH
• Adenoviridae * MeSH
• adjuvancia farmaceutická aplikace a dávkování   MeSH
• akrylamidy aplikace a dávkování   MeSH
• analýza rozptylu MeSH
• farmaceutická vehikula aplikace a dávkování   MeSH
• kombinovaná terapie metody   MeSH
• lidé MeSH
• mikrobubliny MeSH
• myši inbrední BALB C MeSH
• myši SCID MeSH
• myši MeSH
• nádory prsu metabolismus   patologie   terapie   MeSH
• onkolytická viroterapie metody   MeSH
• onkolytické viry * MeSH
• ultrazvuková terapie * MeSH
• xenogenní modely - testy protinádorové aktivity MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH