BackgroundNanotechnology is a science that involves imaging, measurement, modeling and a manipulation of matter at the nanometric scale. One application of this technology is drug delivery systems based on nanoparticles obtained from natural or synthetic sources. An example of these systems is synthetized from poly(3-hydroxybutyrate-co-3-hydroxyvalerate), which is a biodegradable, biocompatible and a low production cost polymer. The aim of this work was to investigate the uptake mechanism of PHBV nanoparticles in two different epithelial cell lines (HeLa and SKOV-3).ResultsAs a first step, we characterized size, shape and surface charge of nanoparticles using dynamic light scattering and transmission electron microscopy. Intracellular incorporation was evaluated through flow cytometry and fluorescence microscopy using intracellular markers. We concluded that cellular uptake mechanism is carried out in a time, concentration and energy dependent way. Our results showed that nanoparticle uptake displays a cell-specific pattern, since we have observed different colocalization in two different cell lines. In HeLa (Cervical cancer cells) this process may occur via classical endocytosis pathway and some internalization via caveolin-dependent was also observed, whereas in SKOV-3 (Ovarian cancer cells) these patterns were not observed. Rearrangement of actin filaments showed differential nanoparticle internalization patterns for HeLa and SKOV-3. Additionally, final fate of nanoparticles was also determined, showing that in both cell lines, nanoparticles ended up in lysosomes but at different times, where they are finally degraded, thereby releasing their contents.ConclusionsOur results, provide novel insight about PHBV nanoparticles internalization suggesting that for develop a proper drug delivery system is critical understand the uptake mechanism.Electronic supplementary materialThe online version of this article (doi:10.1186/s12951-016-0241-6) contains supplementary material, which is available to authorized users.

Research in fluorescence microscopy presents new challenges, especially with respect to the development of new metal-based fluorophores. In this work, the news fac-[Re(CO) 3 (bpy)L]PF 6 (C3) and fac-[Re(CO) 3 (dmb)L]PF 6 (C4) complexes, where L is an ancillary ligand E-2-((3-amino-pyridin-4-ylimino)-methyl)-4,6-diterbutylphenol, both exhibiting an intramolecular hydrogen bond, have been synthesized for its use as preliminary probes for fluorescence microscopy. The complexes were characterized using chemical techniques such as UV-Vis, 1 H-NMR, TOCSY, FT-IR, cyclic voltammetry, mass spectra (EI-MS 752.22 M + for C3 and 780.26 M + for C4) and DFT calculations including spin-orbit effects. The electron withdrawing nature of the ancillary ligand L in C3 and C4 explains their electrochemical behavior, which shows the oxidation of Re I at 1.84 V for C3 and at 1.88 V for C4. The UV-vis absorption and emission properties have been studied at room temperature in acetonitrile solution. The complexes show luminescent emission with a large Stokes shift (λ ex = 366 nm; λ em = 610 nm for C3 and λ ex = 361 nm; λ em = 560 nm for C4). The TDDFT calculations suggest that an experimental mixed absorption band at 360 nm could be assigned to MLCT (d(Re) →π*(dmb))and LLCT (π(L)→π*(dmb)) transitions. We also assessed the cytotoxicity of C3 and C4 in an epithelial cell line (T84). We found that 12.5 µg/ml of C3 or C4 is the minimum concentration needed to kill the 80% of cell population, as determined by neutral red uptake. Finally, the potential of C3 and C4 as biological dyes for use in fluorescent microscopy was assessed in bacteria (Salmonella enterica) and yeasts (Candida albicans and Cryptococcus spp.), and in an ovarian cancer cell line (SKOV-3). We found that, in all cases, both C3 and C4 are suitable compounds to be used as fluorescent dyes for biological purposes. In addition, we present evidence suggesting that these rhenium (I) tricarbonyl complexes may be also useful as differential fluorescent dyes in yeasts (Candida albicans and Cryptococcus spp.), without the need of antibodies.

Poly(amidoamine) dendrimers are the most recognized class of dendrimer. Amino-terminated (PAMAM-NH2) and hydroxyl-terminated (PAMAM-OH) dendrimers of generation 4 are widely used, since they are commercially available. Both have different properties, mainly based on their different overall charges at physiological pH. Currently, an important function of dendrimers as carriers of short single-stranded DNA has been applied. These molecules, known as antisense oligonucleotides (asODNs), are able to inhibit the expression of a target mRNA. Whereas PAMAM-NH2 dendrimers have shown to be able to transfect plasmid DNA, PAMAM-OH dendrimers have not shown the same successful results. However, little is known about their interaction with shorter and more flexible molecules such as asODNs. Due to several initiatives, the use of these neutral dendrimers as a scaffold to introduce other functional groups has been proposed. Because of its low cytotoxicity, it is relevant to understand the molecular phenomena involving these types of dendrimers. In this work, we studied the behavior of an antisense oligonucleotide in presence of both types of dendrimers using molecular dynamics simulations, in order to elucidate if they are able to form stable complexes. In this manner, we demonstrated at atomic level that PAMAM-NH2, unlike PAMAM-OH, could form a well-compacted complex with asODN, albeit PAMAM-OH can also establish stable interactions with the oligonucleotide. The biological activity of asODN in complex with PAMAM-NH2 dendrimer was also shown. Finally, we revealed that in contact with PAMAM-OH, asODN remains outside the cells as TIRF microscopy results showed, due to its poor interaction with this dendrimer and cell membranes.

Since its discovery, cAMP has been proposed as one of the most versatile second messengers. The remarkable feature of cAMP to tightly control highly diverse physiological processes, including metabolism, homeostasis, secretion, muscle contraction, cell proliferation and migration, immune response, and gene transcription, is reflected by millions of different articles worldwide. Compartmentalization of cAMP in space and time, maintained by mainly phosphodiesterases, contributes to the maintenance of equilibrium inside the cell where one signal can trigger many different events. Novel cAMP sensors seem to carry out certain unexpected signaling properties of cAMP and thereby to permit delicate adaptations of biologic responses. Measuring space and time events with biosensors will increase our current knowledge on the pathophysiology of diseases, such as chronic obstructive pulmonary disease, asthma, cognitive impairment, cancer, and renal and heart failure. Further insights into the cAMP dynamics will help to optimize the pharmacological treatment for these diseases.

URREJOLA, M. C.; SOTO, L. V.; ZUMARÁN, C. C.; PEÑALOZA, J. P.; ÁLVAREZ, B.; FUENTEVILLA, I. & HAIDAR, Z. S.Sistemas de Nanopartículas Poliméricas II: estructura, métodos de elaboración, características, propiedades, biofuncionalización y tecnologías de auto-ensamblaje capa por capa (layer-by-layer self-assembly). RESUMEN:Los materiales poliméricos han sido ampliamente investigados para aplicaciones biomédicas, teniendo especial relevancia cuando se encuentran en forma de micro-y nano-partículas. Últimamente se ha ampliado su campo de aplicación al ser conjugados con péptidos y ácidos nucleicos, por lo tanto, el interés en el estudio de este tipo de materiales, así como también en la formulación de nanoestructuras funcionalizadas como materiales, dispositivos y vehículos de transporte de agentes terapéuticos ha aumentado. Las recientes investigaciones en nanosistemas se inspiran en fenómenos naturales que estimulan la integración de señales moleculares y la mimetización de procesos a nivel celular, de tejidos y órganos. Tecnológicamente, la capacidad de obtener nanoestructuras esféricas mediante la combinación de materiales que presenten propiedades distintas a las que ningún otro material individual posee por sí solo, es lo que hace que las nanocápsulas sean particularmente atractivas. Las potenciales ventajas de los sistemas de nanopartículas de tipo polimérico se destacan a lo largo de cada parte de este artículo de revisión. El presente artículo aborda los aspectos más relevantes sobre la estructura, composición y algunos métodos de elaboración de los sistemas nanoparticulados. Además, expone algunos de los trabajos más recientes, centrados en sistemas de nanopartículas basados en polímeros dirigidos a la administración de agentes, publicados en artículos especializados de investigación y revisiones durante los últimos años. URREJOLA, M. C.; SOTO, L. V.; ZUMARÁN, C. C.; PEÑALOZA, J. P.; ÁLVAREZ, B.; FUENTEVILLA, I. & HAIDAR, Z. S. Polymeric Nanoparticle Systems II: structure, elaboration methods, characteristics, properties, biofunctionalization and self-assembly layer by layer technologies.SUMMARY: Polymeric materials have been extensively investigated for biomedical applications including micro-and nanoparticles. Modern advances have broadened horizons for application with peptides and nucleic acids. Therefore, interests increased in the formulation of materials, devices and vehicles for transporting therapeutic agents in functionalized nanostructures. Recent nano-systems are inspired by natural phenomena that stimulate the integration of molecular signals and the mimicking of natural cellular processes, at tissue and organ levels. Technologically, the ability to obtain spherical nanostructures, which combine different properties, that no other single material possesses on its own, makes nanocapsules particularly attractive. Potential advantages over polymer nanoparticulate systems are highlighted throughout each part of this review article. Here, we address the most relevant aspects of structure, compositio...

Recent advances in nanotechnology and nanobiotechnology have contributed to the development of nanomaterials, able to be used as drug carriers, probes, targets or cytostatic drugs by itself. Nanomedicine is now the leading area in nanotechnology where a large number and types of nanoparticles (NPs) has been developed and several are already in the clinical practice. Chemotherapy is one of the most widely used strategies to treat cancer. Most chemotherapeutic agents have poor solubility, low bioavailability, and are formulated with toxic solvents. NPs have been designed to overcome the lack of specificity of chemotherapeutic agents as well to improve circulation time in blood, taking advantages on tumor cells characteristics. In immunology, recent advances regarding the activation of the innate immune system artificially enhanced by NPs functionalized with immune-stimulators open a new window as novel methods in vaccines. Also, viruses and virus-like particles (VLPs) engineered to stimulate immune response against their similar virus or as molecular platforms for the presentation of foreign epitopes have been described. In this review we focused in the use of different types of NPs in oncology and immunology, pinpointing the main novelties regarding their development and use of nanotechnology in a broad array of applications, ranging from tumor diagnostics, immune-modulation up to cancer therapeutics.

RESUMEN: Nanotecnología es la ciencia que involucra la síntesis de materiales en escala entre 1-100 nm (nanomateriales) es aplicable en diferentes áreas tales como medio ambiente, electrónica, alimentos, energía, entre otros. Los campos que serán relevantes dentro de esta revisión y explicados en detalle son la nanomedicina y la nano-odontología. Actualmente, en estas áreas los tres principales temas en desarrollo son específicamente en el sub-área de la nanobiotecnología y corresponden a: sensorización (biosensores/biodetección), diagnóstico (biomarcadores/bioimagen) y transportes de genes, proteínas o fármacos (sistemas de intercambio controlado en blancos sistémicos versus localizados). También se han presentado avances en bioaplicaciones como modelamientos de membranas, marcaje celular, entrega de agentes a blancos específicos, estrategias para prevención de enfermedades, ingeniería de tejidos, regeneración de órganos, estrategias de inmunoensayos y nano-oncología. Este artículo de revisión pretende abordar algunos de los aportes más relevantes, que tienen algunos de los trabajos recientes, sobre los sistemas de nanopartículas, principalmente aquellos dirigidos a terapias en áreas como diabetes, nano-oncología, terapia de fármacos y genes, mediante la técnica layer-by-layer y autoensamblado, muy utilizados también en ingeniería de tejidos y regeneración tisular, junto a un breve resumen de los avances que existen en el campo de la nano-odontología.

Objective: To evaluate the expression of E-cadherin, Vimentin, CD31, CD117 in Oral Epithelial Dysplasia (OED) and Oral Squamous Cell Carcinoma (OSCC), in comparison with Normal Oral Mucosa (NOM). Material and Methods:Descriptive case study. Histological samples were analyzed by immunohistochemistry against E-cadherin, Vimentin, CD31, CD117. E-cadherin expression was evaluated by extent and intensity, Vimentin was evaluated by intensity and CD31 and C117 quantitatively. Results:The extent of E-cadherin was greater than 75% in all NOM samples, 81% of the OED samples and 47% of the OSCC samples. The intensity of E-cadherin was high in NOM (100%) and in OSCC (36%). Mean CD31 was 21.2 ± 5 in NOM samples, 23.4 ± 5.8 in OED samples and 36.7 ± 10.8 in OSCC samples. Mean CD117 was 7.2 ± 2.5 in NOM samples, 12.8 ± 5.3 in OED samples and 22.7 ± 5.3 in OSCC samples. Conclusion:The molecular marker E-cadherin is significantly more downregulated in dysplastic cells in comparison to NOM cells, while the mesenchymal marker Vimentin is expressed by epithelial cells in samples of NOM, OED and OSCC; questioning their value as prognostic markers. Finally, the quantification of CD31 and CD117 increased significantly in OSCC samples.