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1.
Brain Behav Immun ; 117: 493-509, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38307446

RESUMO

In the last years, the hypothesis that elevated levels of proinflammatory cytokines contribute to the pathogenesis of neurodevelopmental diseases has gained popularity. IL-1 is one of the main cytokines found to be elevated in Autism spectrum disorder (ASD), a complex neurodevelopmental condition characterized by defects in social communication and cognitive impairments. In this study, we demonstrate that mice lacking IL-1 signaling display autistic-like defects associated with an excessive number of synapses. We also show that microglia lacking IL-1 signaling at early neurodevelopmental stages are unable to properly perform the process of synapse engulfment and display excessive activation of mammalian target of rapamycin (mTOR) signaling. Notably, even the acute inhibition of IL-1R1 by IL-1Ra is sufficient to enhance mTOR signaling and reduce synaptosome phagocytosis in WT microglia. Finally, we demonstrate that rapamycin treatment rescues the defects in IL-1R deficient mice. These data unveil an exclusive role of microglial IL-1 in synapse refinement via mTOR signaling and indicate a novel mechanism possibly involved in neurodevelopmental disorders associated with defects in the IL-1 pathway.


Assuntos
Transtorno do Espectro Autista , Transtorno Autístico , Animais , Camundongos , Microglia , Serina-Treonina Quinases TOR , Citocinas , Sirolimo/farmacologia , Sinapses , Interleucina-1 , Mamíferos
2.
JHEP Rep ; 6(1): 100910, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38074504

RESUMO

Background & Aims: Cholangiocarcinoma (CCA) is a primary liver tumour characterised by a poor prognosis and limited therapeutic options. Available 3D human CCA models fail to faithfully recapitulate the tumour niche. We aimed to develop an innovative patient-specific CCA-on-chip platform. Methods: A CCA tumour microenvironment was recapitulated on a microfluidic three-channel chip using primary CCA cells, cancer-associated fibroblasts (CAFs), endothelial cells, and T cells isolated from CCA specimens (n = 6). CAF and CCA cells were co-cultured in the central channel, flanked by endothelial cells in one lateral channel, recreating a tubular structure. An extensive characterisation of this platform was carried out to investigate its diffusion ability, hydrogel properties, and changes in matrix composition. Cell phenotype and functional properties were assessed. Results: Primary cells seeded on the microfluidic device were shown to reproduce the architectural structure and maintain the original phenotype and functional properties. The tumour niche underwent a deep remodelling in the 3D device, with an increase in hydrogel stiffness and extracellular matrix deposition, mimicking in vivo CCA characteristics. T cells were incorporated into the device to assess its reliability for immune cell interaction studies. Higher T cell migration was observed using cells from patients with highly infiltrated tumours. Finally, the drug trial showed the ability of the device to recapitulate different drug responses based on patient characteristics. Conclusions: We presented a 3D CCA platform that integrates the major non-immune components of the tumour microenvironment and the T cell infiltrate, reflecting the CCA niche. This CCA-on-chip represents a reliable patient-specific 3D platform that will be of help to further elucidate the biological mechanisms involved in CCA and provide an efficient tool for personalised drug testing. Impact and implications: An innovative patient-specific cholangiocarcinoma (CCA)-on-chip platform was successfully developed, integrating the major components of the tumour microenvironment (tumour cells, cancer-associated fibroblasts, endothelial cells, and immune infiltrate) and faithfully mimicking the CCA niche. This CCA-on-chip represents a powerful tool for unravelling disease-associated cellular mechanisms in CCA and provides an efficient tool for personalised drug testing.

3.
Theranostics ; 13(1): 355-373, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36593955

RESUMO

Rationale: Nanobodies (Nbs) have emerged as an elegant alternative to the use of conventional monoclonal antibodies in cancer therapy, but a detailed microscopic insight into the in vivo pharmacokinetics of different Nb formats in tumor-bearers is lacking. This is especially relevant for the recognition and targeting of pro-tumoral tumor-associated macrophages (TAMs), which may be located in less penetrable tumor regions. Methods: We employed anti-Macrophage Mannose Receptor (MMR) Nbs, in a monovalent (m) or bivalent (biv) format, to assess in vivo TAM targeting. Intravital and confocal microscopy were used to analyse the blood clearance rate and targeting kinetics of anti-MMR Nbs in tumor tissue, healthy muscle tissue and liver. Fluorescence Molecular Tomography was applied to confirm anti-MMR Nb accumulation in the primary tumor and in metastatic lesions. Results: Intravital microscopy demonstrated significant differences in the blood clearance rate and macrophage targeting kinetics of (m) and (biv)anti-MMR Nbs, both in tumoral and extra-tumoral tissue. Importantly, (m)anti-MMR Nbs are superior in reaching tissue macrophages, an advantage that is especially prominent in tumor tissue. The administration of a molar excess of unlabelled (biv)anti-MMR Nbs increased the (m)anti-MMR Nb bioavailability and impacted on its macrophage targeting kinetics, preventing their accumulation in extra-tumoral tissue (especially in the liver) but only partially influencing their interaction with TAMs. Finally, anti-MMR Nb administration not only allowed the visualization of TAMs in primary tumors, but also at a distant metastatic site. Conclusions: These data describe, for the first time, a microscopic analysis of (m) and (biv)anti-MMR Nb pharmacokinetics in tumor and healthy tissues. The concepts proposed in this study provide important knowledge for the future use of Nbs as diagnostic and therapeutic agents, especially for the targeting of tumor-infiltrating immune cells.


Assuntos
Neoplasias , Anticorpos de Domínio Único , Humanos , Receptor de Manose , Lectinas Tipo C , Lectinas de Ligação a Manose , Receptores de Superfície Celular , Macrófagos Associados a Tumor , Neoplasias/tratamento farmacológico
4.
Int J Mol Sci ; 23(14)2022 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-35886970

RESUMO

Here we provide demonstration that fast fluorescence fluctuation spectroscopy is a fast and robust approach to extract information on the dynamics of molecules enclosed within subcellular nanostructures (e.g., organelles or vesicles) which are also moving in the complex cellular environment. In more detail, Raster Image Correlation Spectroscopy (RICS) performed at fast timescales (i.e., microseconds) reveals the fast motion of fluorescently labeled molecules within two exemplary dynamic subcellular nanostructures of biomedical interest, the lysosome and the insulin secretory granule (ISG). The measurement of molecular diffusion is then used to extract information on the average properties of subcellular nanostructures, such as macromolecular crowding or molecular aggregation. Concerning the lysosome, fast RICS on a fluorescent tracer allowed us to quantitatively assess the increase in organelle viscosity in the pathological condition of Krabbe disease. In the case of ISGs, fast RICS on two ISG-specific secreting peptides unveiled their differential aggregation propensity depending on intragranular concentration. Finally, a combination of fast RICS and feedback-based 3D orbital tracking was used to subtract the slow movement of subcellular nanostructures from the fast diffusion of molecules contained within them and independently validate the results. Results presented here not only demonstrate the acquired ability to address the dynamic behavior of molecules in moving, nanoscopic reference systems, but prove the relevance of this approach to advance our knowledge on cell function at the subcellular scale.


Assuntos
Nanoestruturas , Transporte Biológico , Difusão , Movimento (Física) , Espectrometria de Fluorescência/métodos
5.
J Phys Chem B ; 126(2): 480-491, 2022 01 20.
Artigo em Inglês | MEDLINE | ID: mdl-35001625

RESUMO

An integrated theoretical/experimental strategy has been applied to the study of environmental effects on the spectroscopic parameters of 4-(diphenylamino)phtalonitrile (DPAP), a fluorescent molecular rotor. The computational part starts from the development of an effective force field for the first excited electronic state of DPAP and proceeds through molecular dynamics simulations in solvents of different polarities toward the evaluation of Stokes shifts by quantum mechanics/molecular mechanics (QM/MM) approaches. The trends of the computed results closely parallel the available experimental results thus giving confidence to the interpretation of new experimental studies of the photophysics of DPAP in lipid bilayers. In this context, results show unambiguously that both flexible dihedral angles and global rotations are significantly retarded in a cholesterol/DPPC lipid matrix with respect to the DOPC matrix, thus confirming the sensitivity of DPAP to probe different environments and, therefore, its applicability as a probe for detecting different structures and levels of plasma membrane organization.


Assuntos
1,2-Dipalmitoilfosfatidilcolina , Bicamadas Lipídicas , 1,2-Dipalmitoilfosfatidilcolina/química , Colesterol/química , Bicamadas Lipídicas/química , Simulação de Dinâmica Molecular , Fosfatidilcolinas/química , Análise Espectral
6.
Nat Commun ; 13(1): 6, 2022 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-35013167

RESUMO

Myocardial infarction causes 7.3 million deaths worldwide, mostly for fibrillation that electrically originates from the damaged areas of the left ventricle. Conventional cardiac bypass graft and percutaneous coronary interventions allow reperfusion of the downstream tissue but do not counteract the bioelectrical alteration originated from the infarct area. Genetic, cellular, and tissue engineering therapies are promising avenues but require days/months for permitting proper functional tissue regeneration. Here we engineered biocompatible silicon carbide semiconductive nanowires that synthetically couple, via membrane nanobridge formations, isolated beating cardiomyocytes over distance, restoring physiological cell-cell conductance, thereby permitting the synchronization of bioelectrical activity in otherwise uncoupled cells. Local in-situ multiple injections of nanowires in the left ventricular infarcted regions allow rapid reinstatement of impulse propagation across damaged areas and recover electrogram parameters and conduction velocity. Here we propose this nanomedical intervention as a strategy for reducing ventricular arrhythmia after acute myocardial infarction.


Assuntos
Infarto do Miocárdio , Miócitos Cardíacos/fisiologia , Nanofios , Arritmias Cardíacas/terapia , Compostos Inorgânicos de Carbono , Ventrículos do Coração , Humanos , Infarto do Miocárdio/fisiopatologia , Infarto do Miocárdio/terapia , Compostos de Silício
7.
Front Immunol ; 12: 785883, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34868070

RESUMO

The ubiquitous mold Aspergillus fumigatus is the major etiologic agent of invasive aspergillosis, a life-threatening infection amongst immune compromised individuals. An increasing body of evidence indicates that effective disposal of A. fumigatus requires the coordinate action of both cellular and humoral components of the innate immune system. Early recognition of the fungal pathogen, in particular, is mediated by a set of diverse soluble pattern recognition molecules (PRMs) that act as "ancestral antibodies" inasmuch as they are endowed with opsonic, pro-phagocytic and killing properties. Pivotal is, in this respect, the contribution of the complement system, which functionally cooperates with cell-borne pattern recognition receptors (PRRs) and other soluble PRMs, including pentraxins. Indeed, complement and pentraxins form an integrated system with crosstalk, synergism, and regulation, which stands as a paradigm of the interplay between PRMs in the mounting and orchestration of antifungal immunity. Following upon our past experience with the long pentraxin PTX3, a well-established immune effector in the host response to A. fumigatus, we recently reported that this fungal pathogen is targeted in vitro and in vivo by the short pentraxin Serum Amyloid P component (SAP) too. Similar to PTX3, SAP promotes phagocytosis and disposal of the fungal pathogen via complement-dependent pathways. However, the two proteins exploit different mechanisms of complement activation and receptor-mediated phagocytosis, which further extends complexity and integration of the complement-pentraxin crosstalk in the immune response to A. fumigatus. Here we revisit this crosstalk in light of the emerging roles of SAP as a novel PRM with antifungal activity.


Assuntos
Aspergilose/imunologia , Aspergilose/metabolismo , Aspergillus fumigatus/imunologia , Proteína C-Reativa/metabolismo , Ativação do Complemento/imunologia , Proteínas do Sistema Complemento/imunologia , Componente Amiloide P Sérico/imunologia , Animais , Aspergilose/microbiologia , Biomarcadores , Suscetibilidade a Doenças/imunologia , Interações Hospedeiro-Patógeno/imunologia , Humanos , Imunidade Inata , Componente Amiloide P Sérico/metabolismo
8.
Elife ; 102021 09 24.
Artigo em Inglês | MEDLINE | ID: mdl-34558411

RESUMO

Myopalladin (MYPN) is a striated muscle-specific immunoglobulin domain-containing protein located in the sarcomeric Z-line and I-band. MYPN gene mutations are causative for dilated (DCM), hypertrophic, and restrictive cardiomyopathy. In a yeast two-hybrid screening, MYPN was found to bind to titin in the Z-line, which was confirmed by microscale thermophoresis. Cardiac analyses of MYPN knockout (MKO) mice showed the development of mild cardiac dilation and systolic dysfunction, associated with decreased myofibrillar isometric tension generation and increased resting tension at longer sarcomere lengths. MKO mice exhibited a normal hypertrophic response to transaortic constriction (TAC), but rapidly developed severe cardiac dilation and systolic dysfunction, associated with fibrosis, increased fetal gene expression, higher intercalated disc fold amplitude, decreased calsequestrin-2 protein levels, and increased desmoplakin and SORBS2 protein levels. Cardiomyocyte analyses showed delayed Ca2+ release and reuptake in unstressed MKO mice as well as reduced Ca2+ spark amplitude post-TAC, suggesting that altered Ca2+ handling may contribute to the development of DCM in MKO mice.


Assuntos
Cardiomiopatia Dilatada/genética , Proteínas Musculares/genética , Pressão/efeitos adversos , Animais , Cálcio/metabolismo , Cardiomiopatia Dilatada/patologia , Cardiomiopatia Dilatada/fisiopatologia , Conectina/metabolismo , Masculino , Camundongos Knockout , Proteínas Musculares/química , Proteínas Musculares/metabolismo , Proteínas Mutantes/química , Proteínas Mutantes/genética , Proteínas Mutantes/metabolismo , Mutação , Miocárdio , Miócitos Cardíacos/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Sarcômeros , Técnicas do Sistema de Duplo-Híbrido
9.
J Vis Exp ; (174)2021 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-34459819

RESUMO

Imaging-derived mean square displacement (iMSD) is used to address the structural and dynamic properties of subcellular nanostructures, such as vesicles involved in the endo/exocytotic trafficking of solutes and biomolecules. iMSD relies on standard time-lapse imaging, is compatible with any optical setup, and does not need to dwell on single objects to extract trajectories. From each iMSD trace, a unique triplet of average structural and dynamic parameters (i.e., size, local diffusivity, anomalous coefficient) is calculated and combined to build the "iMSD signature" of the nanostructure under study. The potency of this approach is proved here with the exemplary case of macropinosomes. These vesicles evolve in time, changing their average size, number, and dynamic properties passing from early to late stages of intracellular trafficking. As a control, insulin secretory granules (ISGs) are used as a reference for subcellular structures that live in a stationary state in which the average structural and dynamic properties of the whole population of objects are invariant in time. The iMSD analysis highlights these peculiar features quantitatively and paves the way to similar applications at the sub-cellular level, both in the physiological and pathological states.


Assuntos
Endossomos , Nanoestruturas , Processamento de Imagem Assistida por Computador , Vesículas Secretórias , Análise Espectral
10.
Biomolecules ; 10(12)2020 12 18.
Artigo em Inglês | MEDLINE | ID: mdl-33353213

RESUMO

Molecular imaging is constantly growing in different areas of preclinical biomedical research. Several imaging methods have been developed and are continuously updated for both in vivo and in vitro applications, in order to increase the information about the structure, localization and function of molecules involved in physiology and disease. Along with these progresses, there is a continuous need for improving labeling strategies. In the last decades, the single domain antigen-binding fragments nanobodies (Nbs) emerged as important molecular imaging probes. Indeed, their small size (~15 kDa), high stability, affinity and modularity represent desirable features for imaging applications, providing higher tissue penetration, rapid targeting, increased spatial resolution and fast clearance. Accordingly, several Nb-based probes have been generated and applied to a variety of imaging modalities, ranging from in vivo and in vitro preclinical imaging to super-resolution microscopy. In this review, we will provide an overview of the state-of-the-art regarding the use of Nbs in several imaging modalities, underlining their extreme versatility and their enormous potential in targeting molecules and cells of interest in both preclinical and clinical studies.


Assuntos
Antineoplásicos/química , Imagem Molecular/métodos , Neoplasias/terapia , Medicina de Precisão/métodos , Anticorpos de Domínio Único/química , Animais , Sistema Nervoso Central , Progressão da Doença , Corantes Fluorescentes , Humanos , Inflamação , Camundongos , Neoplasias/metabolismo , Pesquisa Translacional Biomédica
11.
Sci Rep ; 9(1): 1508, 2019 02 06.
Artigo em Inglês | MEDLINE | ID: mdl-30728410

RESUMO

Lipid lateral diffusion in membrane bilayers is a fundamental process exploited by cells to enable complex protein structural and dynamic reorganizations. For its importance, lipid mobility in both cellular and model bilayers has been extensively investigated in recent years, especially through the application of time-resolved, fluorescence-based, optical microscopy techniques. However, one caveat of fluorescence techniques is the need to use dye-labeled variants of the lipid of interest, thus potentially perturbing the structural and dynamic properties of the native species. Generally, the effect of the dye/tracer molecule is implicitly assumed to be negligible. Nevertheless, in view of the widespread use of optically modified lipids for studying lipid bilayer dynamics, it is highly desirable to well assess this point. Here, fluorescence correlation spectroscopy (FCS) and molecular dynamics (MD) simulations have been combined together to uncover subtle structural and dynamic effects in DOPC planar membranes enriched with a standard Rhodamine-labeled lipid. Our findings support a non-neutral role of the dye-labeled lipids in diffusion experiments, quantitatively estimating a decrease in lipid mobility of up to 20% with respect to the unlabeled species. Moreover, results highlight the existing interplay between dye concentration, lipid lateral diffusion and membrane permeability, thus suggesting possible implications for future optical microscopy studies of biophysical processes occurring at the membrane level.


Assuntos
Permeabilidade da Membrana Celular , Membrana Celular/química , Corantes Fluorescentes/química , Bicamadas Lipídicas/química , Lipídeos de Membrana/química , Modelos Biológicos , Simulação de Dinâmica Molecular , Membrana Celular/metabolismo , Biologia Computacional , Difusão , Fluorescência , Corantes Fluorescentes/metabolismo , Humanos , Bicamadas Lipídicas/metabolismo , Lipídeos de Membrana/metabolismo , Microscopia Confocal , Espectrometria de Fluorescência
12.
ACS Nano ; 13(2): 1670-1682, 2019 02 26.
Artigo em Inglês | MEDLINE | ID: mdl-30649861

RESUMO

The eukaryotic cell compartmentalizes into spatially confined, membrane-enclosed, intracellular structures ( e. g., organelles, endosomes, and vesicles). Here, peculiar physicochemical properties of the local environment occur and participate in the regulation of ongoing molecular processes. In spite of the huge amount of available environmental probes, experiments on subcellular structures are severely challenged by their three-dimensional (3D) movement. This bottleneck is tackled here by focusing an excitation light beam in a periodic orbit around the structure of interest. The recorded signal is used as feedback to localize the structure position at high temporal resolution: microseconds along the orbit, milliseconds between orbits. The lysosome is selected as the intracellular target, together with 6-acetyl-2-dimethylaminonaphthalene (ACDAN) as probe of the physicochemical properties of the intralysosomal environment. Generalized polarization (GP) analysis of ACDAN emission is used to get a quantitative view on intralysosomal solvent dipolar relaxation. Thus, raster image correlation spectroscopy (RICS) analysis reveals that the ACDAN GP signal is fluctuating in the micro-to-millisecond time range during natural organelle 3D trafficking. We show that ACDAN GP fluctuations are characteristic of lysosomes in living cells, are selectively abolished by lysosomal basification, and depend on metabolic energy in the form of ATP. We argue that intralysosomal ACDAN GP fluctuates according to the ongoing organelle metabolism. Indeed, we report alterations in amplitude and timing of GP fluctuations in a cellular model of lysosomal storage disorder (LSD). The strategy proposed provides insight into the elusive local environment of a trafficking lysosome and supports similar molecular investigations at the subcellular level.


Assuntos
Lisossomos/química , Lisossomos/metabolismo , Animais , Movimento Celular/fisiologia , Endossomos/química , Humanos , Solventes/química
13.
Sci Data ; 5: 180191, 2018 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-30226484

RESUMO

Time-lapse optical microscopy datasets from living cells can potentially afford an enormous amount of quantitative information on the relevant structural and dynamic properties of sub-cellular organelles/structures, provided that both the spatial and temporal dimensions are properly sampled during the experiment. Here we provide exemplary live-cell, time-lapse confocal imaging datasets corresponding to three sub-cellular structures of the endo-lysosomal pathway, i.e. early endosomes, late endosomes and lysosomes, along with detailed guidelines to produce analogous experiments. Validation of the datasets is conducted by means of established analytical tools to extract the structural and dynamic properties at the sub-cellular scale, such as Single Particle Tracking (SPT) and imaging derived Mean Square Displacement (iMSD) analyses. In our aim, the present work would help other researchers in the field to reuse the provided datasets for their own scopes, and to combine their creative approaches/analyses to similar acquisitions.


Assuntos
Endossomos , Lisossomos , Imagem com Lapso de Tempo , Endossomos/química , Endossomos/ultraestrutura , Células HeLa , Humanos , Processamento de Imagem Assistida por Computador , Lisossomos/química , Lisossomos/ultraestrutura , Microscopia Confocal
14.
Biochem Biophys Res Commun ; 503(4): 2704-2709, 2018 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-30100062

RESUMO

Lysosomes are not merely degradative organelles but play a central role in nutrient sensing, metabolism and cell-growth regulation. Our ability to study their function in living cells strictly relies on the use of lysosome-specific fluorescent probes tailored to optical microscopy applications. Still, no report thus far quantitatively analyzed the effect of labeling strategies/procedures on lysosome properties in live cells. We tackle this issue by a recently developed spatiotemporal fluctuation spectroscopy strategy that extracts structural (size) and dynamic (diffusion) properties directly from imaging, with no a-priori knowledge of the system. We highlight hitherto neglected alterations of lysosome properties upon labeling. In particular, we demonstrate that Lipofectamine reagents, used to transiently express lysosome markers fused to fluorescent proteins (FPs) (e.g. LAMP1-FP or CD63-FP), irreversibly alter the organelle structural identity, inducing a ∼2-fold increase of lysosome average size. The organelle structural identity is preserved, instead, if electroporation or Effectene are used as transfection strategies, provided that the expression levels of the recombinant protein marker are kept low. This latter condition can be achieved also by generating cell lines stably expressing the desired FP-tagged marker. Reported results call into question the interpretation of a massive amount of data collected so far using fluorescent protein markers and suggest useful guidelines for future studies.


Assuntos
Proteínas de Membrana Lisossomal/genética , Lisossomos/metabolismo , Imagem Óptica/estatística & dados numéricos , Proteínas Recombinantes de Fusão/genética , Coloração e Rotulagem/métodos , Tetraspanina 30/genética , Eletroporação/métodos , Corantes Fluorescentes/química , Corantes Fluorescentes/metabolismo , Genes Reporter , Células HeLa , Humanos , Lipídeos/farmacologia , Proteínas de Membrana Lisossomal/metabolismo , Lisossomos/efeitos dos fármacos , Lisossomos/ultraestrutura , Imagem Óptica/métodos , Plasmídeos/química , Plasmídeos/metabolismo , Proteínas Recombinantes de Fusão/metabolismo , Espectrometria de Fluorescência/métodos , Coloração e Rotulagem/normas , Tetraspanina 30/metabolismo , Transfecção
15.
ACS Omega ; 3(6): 6143-6150, 2018 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-30023942

RESUMO

Drug delivery monitoring and tracking in the human body are two of the biggest challenges in targeted therapy to be addressed by nanomedicine. The ability of imaging drugs and micro-/nanoengineered drug carriers and of visualizing their interactions at the cellular interface in a label-free manner is crucial in providing the ability of tracking their cellular pathways and will help understand their biological impact, allowing thus to improve the therapeutic efficacy. We present a fast, label-free technique to achieve high-resolution imaging at the mid-infrared (MIR) spectrum that provides chemical information. Using our custom-made benchtop infrared microscope using a high-repetition-rate pulsed laser (80 MHz, 40 ps), we were able to acquire images with subwavelength resolution (0.8 × λ) at very high speeds. As a proof-of-concept, we embarked on the investigation of nanoengineered polyelectrolyte capsules (NPCs) containing the anticancer drug, docetaxel. These NPCs were synthesized using a layer-by-layer approach built upon a calcium carbonate (CaCO3) core, which was then removed away with ethylenediaminetetraacetic acid. The obtained MIR images show that NPCs are attached to the cell membrane, which is a good step toward an efficient drug delivery. This has been confirmed by both three-dimensional confocal fluorescence and stimulated emission depletion microscopy. Coupled with additional instrumentation and data processing advancements, this setup is capable of video-rate imaging speeds and will be significantly complementing current super-resolution microscopy techniques while providing an unperturbed view into living cells.

16.
Sci Rep ; 7(1): 14836, 2017 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-29093485

RESUMO

Here we provide demonstration that image mean square displacement (iMSD) analysis is a fast and robust platform to address living matter dynamic organization at the level of sub-cellular nanostructures (e.g. endocytic vesicles, early/late endosomes, lysosomes), with no a-priori knowledge of the system, and no need to extract single trajectories. From each iMSD, a unique triplet of average parameters (namely: diffusivity, anomalous coefficient, size) are extracted and represented in a 3D parametric space, where clustering of single-cell points readily defines the structure "dynamic fingerprint", at the whole-cell-population level. We demonstrate that different sub-cellular structures segregate into separate regions of the parametric space. The potency of this approach is further proved through application to two exemplary, still controversial, cases: i) the intracellular trafficking of lysosomes, comprising both free diffusion and directed motion along cytoskeletal components, and ii) the evolving dynamic properties of macropinosomes, passing from early to late stages of intracellular trafficking. We strongly believe this strategy may represent a flexible, multiplexed platform to address the dynamic properties of living matter at the sub-cellular level, both in the physiological and pathological state.


Assuntos
Endocitose , Endossomos/metabolismo , Lisossomos/metabolismo , Difusão , Células HeLa , Humanos , Processamento de Imagem Assistida por Computador/métodos , Cinética , Microscopia Confocal/métodos , Microscopia de Fluorescência/métodos
17.
Phys Chem Chem Phys ; 19(35): 23910-23914, 2017 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-28836633

RESUMO

By a combination of UV-Vis analyses, NMR-based diffusion measurements and MD simulations we have demonstrated for the first time that the HIV-1 Tat arginine-rich peptide (Tat11) is able to self-aggregate in both its fluorescently labeled and unlabeled variants. We propose Tat11 dimerization as the dominant aggregation process and show that the associated equilibrium constant increases ten-fold by labeling with the standard TAMRA dye. Also, we extend similar conclusions to other cationic cell penetrating peptides (CPPs), such as Antennapedia (Ant) and nona-arginine (R9).

18.
Pharmaceuticals (Basel) ; 9(3)2016 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-27399724

RESUMO

Polylactic acid was combined with lemongrass essential oil (EO) to produce functional nanocapsules (NCs). The obtained polylactic acid nanoparticles showed antimicrobial activity both with and without the presence of lemongrass oil; however, the presence of EO improved the activity of the NCs. The presence of lemongrass assisted the formation of well-separated NCs and also provided enhanced antimicrobial properties, since lemongrass is known for its antimicrobial character. Fluorescence microscopy was used to optically observe the nanoparticles and NCs and revealed the attachment of lemongrass oil with the polylactic acid NCs. Dynamic light scattering was used to determine their size. UV absorption was used to determine the exact amount of lemongrass oil found in the polylactic acid-lemongrass oil NCs, which was important for understanding the minimum inhibitory concentration for the antimicrobial experiments. A series of clinically important microbial species were used in the study and the obtained NCs proved to have very good antimicrobial properties against all tested strains. Such NCs can be used for the design of ecological strategies, based on natural alternatives, which may be efficient against severe infections, including those that involve resistant pathogens and biofilms or those with difficult to reach localization.

19.
Small ; 12(22): 3005-13, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27060934

RESUMO

Liquid-liquid interfaces are highly dynamic and characterized by an elevated interfacial tension as compared to solid-liquid interfaces. Therefore, they are gaining an increasing interest as viable templates for ordered assembly of molecules and nanoparticles. However, liquid-liquid interfaces are more difficult to handle compared to solid-liquid interfaces; their intrinsic instability may affect the assembly process, especially in the case of multiple deposition. Indeed, some attempts have been made in the deposition of polymer multilayers at liquid-liquid interfaces, but with limited control over size and stability. This study reports on the preparation of an ultrastable liquid-liquid interface based on an O/W secondary miniemulsion and its possible use as a template for the self-assembly of polymeric multilayer nanocapsules. Such polymer nanocapsules are made of entirely biodegradable materials, with highly controlled size-well under 200 nm-and multi-compartment and multifunctional features enriching their field of application in drug delivery, as well as in other bionanotechnology fields.


Assuntos
Nanocápsulas/química , Nanopartículas/química , Polímeros/química , Sistemas de Liberação de Medicamentos/métodos , Nanotecnologia/métodos , Tamanho da Partícula
20.
Int J Pharm ; 510(2): 508-15, 2016 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-26827919

RESUMO

Nanocapsules and nanoparticles play an essential role in the delivery of pharmaceutical agents in modern era, since they can be delivered in specific tissues and cells. Natural polymers, such as cellulose acetate, are becoming very important due to their availability, biocompatibility, absence of toxicity and biodegradability. In parallel, essential oils are having continuous growth in biomedical applications due to the inherent active compounds that they contain. A characteristic example is lemongrass oil that has exceptional antimicrobial properties. In this work, nanocapsules of cellulose acetate with lemongrass oil were developed with the solvent/anti-solvent method with resulting diameter tailored between 95 and 185nm. Various physico-chemical and surface analysis techniques were employed to investigate the formation of the nanocapsules. These all-natural nanocapsules found to well bioadhere to mucous membranes and to have very good antimicrobial properties at little concentrations against Escherichia coli and Staphylococcus aureus.


Assuntos
Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Celulose/análogos & derivados , Nanocápsulas/química , Óleos Voláteis/química , Óleos de Plantas/química , Óleos de Plantas/farmacologia , Terpenos/química , Terpenos/farmacologia , Celulose/química , Escherichia coli/efeitos dos fármacos , Testes de Sensibilidade Microbiana/métodos , Óleos Voláteis/farmacologia , Solventes/química , Staphylococcus aureus/efeitos dos fármacos
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