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

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

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

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

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

Cíl: Zhodnotit možnosti kontrastní ultrasonografie (CEUS) při klasifikaci cystických ložisek ledvin a srovnat výsledky s výpočetní tomografií (CT). Metodika: Soubor tvoří 112 ložisek u 94 pacientů, kteří měli proveden CEUS a CT ledvin s nálezem cystického ložiska alespoň na jedné z metod. Ložiska byla hodnocena podle Bosniakovy klasifikace a byla buď ověřena histologicky nebo sledována alespoň 2 roky. Hodnocena byla korelace mezi metodami, citlivost metod k detekci jednotlivých znaků používaných v Bosniakově klasifikaci, dále senzitivita a specificita při odlišení maligního a benigního ložiska jednak z pohledu Bosniakovy klasifikace, jednak z pohledu jednotlivých znaků. Data byla zpracována pomocí ROC analýzy. Pro hodnocení statistické významnosti rozdílů v citlivosti sledovaných metod byl použit Fisherův exaktní test. Výsledky: Celková shoda mezi metodami byla 61 %, při rozdělení na nechirurgické (I, II, IIF) a chirurgické (III, IV, solidní) leze byla shoda 90 %. Senzitivita CEUS při tomto rozdělení byla 92,3 %, senzitivita CT 69,2 %, specificita CEUS 90,9 %, CT 94,9 %. CEUS byl statisticky významně citlivější v detekci sept než CT (53 % vs. 25 % ložisek, p < 0,001) a také v detekci sycení sept (22% vs. 10 % ložisek; p = 0, 006). V detekci sycení solidní složky nebyl prokázán statisticky významný rozdíl mezi metodami, na CEUS však byl tento znak významnější pro detekci malignity (zvýšení pravděpodobnosti malignity 384krát na CEUS, 78krát na CT; p< 0,001). Závěr: Výsledky CEUS korelují s výsledky CT. Senzitivita CEUS k detekci maligních ložisek je vyšší než u CT, specificita je mírně nižší.

Aim: To evaluate the classification of cystic renal lesions with CEUS and compare the results with CT. Method: The set consists of 112 lesions in 94 patients who had renal lesion on CEUS and CT with cystic appearance on at least one of the methods. Lesions were evaluated by Bosniak classification and either histologically verified or followed-up for at least two years. We assessed correlation between methods, sensitivity and specificity for detection of features used in Bosniak classification, sensitivity and specificity for malignancy from the viewpoint of Bosniak classification and that of individual features. Data were processed by ROC analysis. Statistical significance was assessed by Fishers exact test. Results: Overall agreement between methods was 61%, with division to non-surgical (category I, II, IIF) and surgical (III, IV, solid) lesions agreement was 90%. With this division sensitivity was 92.3% for CEUS, 69.2% for CT, specificity 90.9% for CEUS and 94.9% for CT. CEUS was more sensitive than CT in detecting septa (53% vs. 25% of lesions; p < 0.001) and in detecting enhancement of septa (22% vs. 10% of lesions; p = 0, 006). Detection of enhancement of solid component was not significantly different, but on CEUS it was more important factor for malignancy detection (increased likelihood of malignancy 384 times on CEUS, 78 times on CT, p < 0.001). Conclusion: Results of CEUS correlate with CT. Sensitivity of CEUS for the detection of malignancy is higher than that of CT, specificity is slightly lower.

• MeSH
• cystická onemocnění ledvin * klasifikace   patologie   radiografie   ultrasonografie   MeSH
• fosfolipidy diagnostické užití   MeSH
• lidé MeSH
• mikrobubliny MeSH
• nádory ledvin * klasifikace   patologie   radiografie   ultrasonografie   MeSH
• počítačová rentgenová tomografie metody   MeSH
• ROC křivka MeSH
• senzitivita a specificita MeSH
• ultrasonografie metody   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• práce podpořená grantem MeSH

The Enhanced Permeability and Retention (EPR) effect is extensively used in drug delivery research. Taking into account that EPR is a highly variable phenomenon, we have here set out to evaluate if contrast-enhanced functional ultrasound (ceUS) imaging can be employed to characterize EPR-mediated passive drug targeting to tumors. Using standard fluorescence molecular tomography (FMT) and two different protocols for hybrid computed tomography-fluorescence molecular tomography (CT-FMT), the tumor accumulation of a ~10 nm-sized near-infrared-fluorophore-labeled polymeric drug carrier (pHPMA-Dy750) was evaluated in CT26 tumor-bearing mice. In the same set of animals, two different ceUS techniques (2D MIOT and 3D B-mode imaging) were employed to assess tumor vascularization. Subsequently, the degree of tumor vascularization was correlated with the degree of EPR-mediated drug targeting. Depending on the optical imaging protocol used, the tumor accumulation of the polymeric drug carrier ranged from 5 to 12% of the injected dose. The degree of tumor vascularization, determined using ceUS, varied from 4 to 11%. For both hybrid CT-FMT protocols, a good correlation between the degree of tumor vascularization and the degree of tumor accumulation was observed, within the case of reconstructed CT-FMT, correlation coefficients of ~0.8 and p-values of <0.02. These findings indicate that ceUS can be used to characterize and predict EPR, and potentially also to pre-select patients likely to respond to passively tumor-targeted nanomedicine treatments.

• MeSH
• akrylamidy aplikace a dávkování   MeSH
• enbukrylát MeSH
• kontrastní látky aplikace a dávkování   MeSH
• krevní objem MeSH
• lékové transportní systémy * MeSH
• mikrobubliny MeSH
• myši nahé MeSH
• nádorové buněčné linie MeSH
• nádory krevní zásobení   metabolismus   patofyziologie   ultrasonografie   MeSH
• permeabilita MeSH
• regionální krevní průtok MeSH
• tomografie metody   MeSH
• zvířata MeSH
• Check Tag
• 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

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

• MeSH
• gadolinium kontraindikace   škodlivé účinky   MeSH
• jod MeSH
• kojení MeSH
• kontrastní látky * aplikace a dávkování   škodlivé účinky   MeSH
• lidé MeSH
• magnetická rezonanční tomografie kontraindikace   škodlivé účinky   MeSH
• mikrobubliny kontraindikace   škodlivé účinky   využití   MeSH
• radiografie kontraindikace   škodlivé účinky   MeSH
• radiologie trendy   MeSH
• síran barnatý MeSH
• těhotenství MeSH
• ultrasonografie kontraindikace   škodlivé účinky   MeSH
• Check Tag
• lidé MeSH
• těhotenství MeSH
• ženské pohlaví MeSH