Cellular Alterations in Carbohydrate and Lipid Metabolism Due to Interactions with Nanomaterials

Nanoparticles (NPs) have unique physicochemical properties that are useful for a broad range of biomedical and industrial applications; nevertheless, increasing concern exists about their biosafety. This review aims to focus on the implications of nanoparticles in cellular metabolism and their outcomes. In particular, some NPs have the ability to modify glucose and lipid metabolism, and this feature is especially interesting to treat diabetes and obesity and to target cancer cells. However, the lack of specificity to reach target cells and the toxicological evaluation of nontargeted cells can potentially induce detrimental side effects, closely related to inflammation and oxidative stress. Therefore, identifying the metabolic alterations caused by NPs, independent of their application, is highly needed. To our knowledge, this increase would lead to the improvement and safer use with a reduced toxicity, increasing the number of available NPs for diagnosis and treatment of human diseases

Molecular biology of malignant melanoma

El pdf es la versión post-print.The incidence of melanoma has increased more rapidly than any other type of cancer. In this review, we summarize the most important genetic alterations that contribute to the development of malignant melanoma. Our knowledge of the genetic and biological events involved in the genesis and progression of this disease has been benefited from the evolvement of a wealth of genetically engineered animal models. Hopefully, the understanding generated by all these studies will contribute to develop new therapeutic strategies to handle this fatal malignancy. © 2008 Springer New York.Work in our laboratory has been funded by the Spanish Ministry of Education (grant SAF2004-04902 to MQ) and Fides and Medical Research Funds (grant PI05626 to PM-D). MP is funded by the company Digna Biotech. PM-D is funded by the >Ramón y Cajal> program.Peer Reviewe

PAMAM-based dendrimers for diverse biomedical applications

Existe una gran necesidad de nuevos tratamientos en determinadas patologías tales como el cáncer o las infecciones resistentes. Entre algunas de las nuevas terapias más prometedoras se encuentran génica y celular, pero ambas tienen serios problemas que resolver antes de pasar a la clínica. Para resolver algunos de estos problemas, recientemente se han combinado vectores virales con células madre (células madre mesenquimales especialmente). Sin embargo, ya que son células complejas de crecer con los métodos y medios de cultivo estándar, la técnica tiene que ser mejorado antes de ser poder ser utilizado en ensayos clínicos. Vectores sintéticos tales como polímeros, aunque más seguros que los virus, generalmente no poseen la eficacia requerida para los tratamiento de terapia génica. En este ámbito, los dendrímeros son polímeros sintéticos tridimensionales, altamente ramificados y con una estructura química bien definida. En particular, los dendrímeros basados en PAMAM (poli(amidoamina)) han sido ampliamente investigados por sus aplicaciones biológicas y han mostrado ser portadores de propiedades clínicamente relevantes que les hacen valiosos para ser utilizados en terapia génica o celular. Se ha demostrado que los dendrímeros basados en PAMAM también pueden facilitar la localización de antibióticos en el interior de bacterias, y por lo tanto, pueden ser utilizados para mejorar la actividad antimicrobiana. Además, pueden ser altamente tóxicos para determinadas bacterias mediante la disrupción de la membrana citoplasmática. Controlando la funcionalidad y carga a través de la elección de los grupos periféricos, el tamaño del dendrímero y el nivel de recubrimiento con PEG, se pueden modular las interacciones con la superficie bacteriana y su actividad antibacteriana y citotóxica para las células huésped. En este proyecto se han estudiado las propiedades biomédicas de derivados de PAMAM y su influencia sobre el crecimiento bacteriano y celular. Nuestros resultados muestran que, aunque el dendrímero PAMAM completamente recubierto con PEG disminuye el crecimiento de Pseudomonas y que tiene potencial para ser empleado como un agente antibacteriano, en el caso de las células madre mesenquimales, el crecimiento celular se incrementa sin alterar sus patrones de pluripotencialidad y podría ser de gran ayuda para las futuras estrategias de terapia celular

Exosomes loaded with ultrasmall Pt nanoparticles: a novel low-toxicity alternative to cisplatin

Background: Platinum nanoparticles have been demonstrated to have excellent anticancer properties. However, because of the lack of specificity they must be delivered to the tumor in amounts sufficient to reach the desired therapeutic objectives. Interestingly, exosomes are considered as excellent natural selective delivery nanotools, but until know their targeting properties have not being combined with the anticancer properties of platinum nanoparticles. Results: In this work we combine the targeting capabilities of exosomes and the antitumoral properties of ultrasmall (< 2 nm) platinum nanoparticles as a novel, low toxicity alternative to the use of cisplatin. A mild methodology based on the room temperature CO-assisted in situ reduction of Pt2+ precursor was employed to preserve the integrity of exosomes, while generating ultrasmall therapeutic PtNPs directly inside the vesicles. The resulting PtNPs-loaded exosomes constitute a novel hybrid bioartificial system that was readily internalized by the target cells inducing antiproliferative response, as shown by flow cytometry and microscopy experiments in vitro. In vivo Pt-Exos showed antitumoral properties similar to that of cisplatin but with a strongly reduced or in some cases no toxic effect, highlighting the advantages of this approach and its potential for translation to the clinic. Conclusions: In this study, a nanoscale vector based on ultrasmall PtNPs and exosomes has been created exhibiting antitumoral properties comparable or higher to those of the FDA approved cisplatin. The preferential uptake of PtNPs mediated by exosomal transfer between certain cell types has been exploited to create a selective antitumoral novel bioartificial system. We have demonstrated their anticancer properties both in vitro and in vivo comparing the results obtained with the administration of equivalent amounts of cisplatin, and showing a spectacular reduction of toxicity. © 2022, The Author(s)

Use of Placental MSCs and their exosomes as theragnostic agents for cancer treatment and diagnostic.

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Polymer functionalized gold nanoparticles as non-viral gene delivery reagents.

Background: In this study we investigated the ability of PEG functionalized gold nanoparticles as non-viral vectors in the transfection of different cell lines, comparing them with commercial lipoplexes. Methods: Positively charged gold nanoparticles were synthesized using PEI as reducing and stabilizer agent and its cytotoxicity reduced by its functionalization with PEG. We bound the nanoparticles to three plasmids with different sizes (4-40 kpb). The vector internalization was evaluated by confocal and electronic microscopy. Its transfection efficacy was studied by fluorescence microscopy and flow cytometry. The application of the resulting vector in gene therapy was indirectly evaluated using ganciclovir in HeLa cells transfected to express the herpes virus thymidine kinase. Results: An appropriate ratio between the nitrogen from the PEI and the phosphorous from the phosphate groups of the DNA together with a reduced size and an elevated electrokinetic potential are responsible for an increased nanoparticle internalization and enhanced protein expression when carrying plasmids of up to 40kbp (plasmid size close to the limit of the DNA carrying capacity of viral vectors). Compared to a commercial transfection reagent, an equal or even higher expression of reporter genes (on HeLa and HEK 293T) and suicide effect on HeLa cells transfected with the herpes virus thymidine kinase gene were observed when using this novel nanoparticulated vector. Conclusions: Non-viral vectors based on gold nanoparticles covalently coupled with polyethylene glycol (PEG) and Polyethylenimine (PEI) can be used as efficient transfection reagents showing expression levels same or greater than the ones obtained with commercially available lipoplexes.pre-print3905 K

Funcionalización de matriz hepática para su recelularización en biorreactor y su trasplante in vivo

El objetivo principal de este proyecto es la descelularizacion de un órgano completo eliminando todo vestigio celular vivo, conservando la estructura extracelular, de tal modo que pueda ser recolonizado manteniendo la histología y recelularizarlo con células madre propias, con capacidad de autorrenovarse y diferenciarse en células especializadas en respuesta a señales especificas, para su posterior transplante in vivo. Dada la escasez de donantes validos o compatibilidad en el caso de un trasplante de órgano, junto al aumento de muertes por este motivo y otros condicionantes, le dan al proyecto un marcado carácter global, ya que en un futuro cercano tras varios años de desarrollo, experimentación y depuración se puede llegar a generar órganos Bioartificiales con funciones complejas y multitud de diferentes estirpes celulares, cultivados con las propias células madre del hipotético receptor, a partir de matrices naturales. Todo ello ha permanecido en el campo experimental, con muchas limitaciones y aunque esta posibilidad tiene visos de hacerse realidad pronto, todavía estamos en el comienzo de la investigación

The effect of hollow gold nanoparticles on stem cell migration. Potencial application in tissue regeneration.

Every year trauma together with bone, joints and cartilage-associated diseases usually involve structural damage, resulting in a severe pain and disability for millions of people worldwide[1]. In regenerative medicine, cellular, tissue and organ-based approaches are developed to restore biological functions that have been lost[2],[3]. Therefore, tissue repair and regenerative medicine have attracted the interest of the scientific community, providing promising results in preclinical models and clinical pilot studies.pre-print3341 K

Selective delivery of photothermal nanoparticles to tumors using mesenchymal stem cells as Trojan horses

The main challenge of cancer treatment is to avoid or minimize systemic side effects in off-target tissues. Mesenchymal stem cells (MSCs) can be used as therapeutical carriers because of their ability to migrate and incorporate into inflammation areas including tumors. Here, this homing ability is exploited by carrying therapeutic nanoparticles (Hollow Gold Nanoparticles (HGNs)) following a “Trojan-horse” strategy. Amongst the different nanoparticles to be employed, HGNs have the capacity to resonate in the near infrared region when irradiated by an appropriated laser (808 nm). By transforming this absorbed energy into heat, they are capable to produce locally induced hyperthermia. At this wavelength healthy tissues have a minimal light absorption being the effect restricted to the tissues containing HGNs. By placing HGNs inside MSCs, the recognition, excretion and immune response are minimized. We demonstrate that MSCs internalize HGNs and reach the tumors still containing HGNs. After laser treatment this loaded cells are able to eradicate tumoral cells in vitro and in vivo without significant toxicity. Also Ki67 expression, which is usually correlated with proliferation, is reduced after treatment. This approach enhances the effectiveness of the treatment when compared to just the enhanced permeation and retention effect (EPR) of the HGNs by themselves

Extracellular vesicles from induced neurons trigger epigenetic silencing of a brain neurotransmitter.

Introduction: Antithrombin (AT) is a glycoprotein involved in the regulation of blood coagulation. It belongs to the family of serine-protease inhibitors and acts as the most important antagonist of different clot- ting factors. Two types of inherited AT deficiency can be distinguished: Type I (quantitative deficit), and Type II (qualitative deficit). The latter is characterized by an impaired inhibitory activity related to dysfunc- tional domains of the protein. Three Type II subtypes can be defined: Type IIa (reactive site defect), Type IIb (heparin binding site defect) and Type IIc (pleiotropic defect). This classification has clinical importance since these subtypes have a different thrombotic risk. No functional routine diagnostic assay, however, can be assumed to detect all forms of Type II deficiencies since false-negative results may hamper the diagnosis. Methods: We analysed the biochemical/biophysical association of ATT to EVs. We separated EVs from plasma of healthy or Type II affected patients or from cultured hepatocytes through differential ultracentrifu- gation followed by sucrose density gradient and/or immunoprecipitation. We next combined dot blot ana- lysis, WB, 2D electrophoresis and enzymatic assays to reveal the nature of ATT association to EVs. Results: We evidenced that ATT is associated to the external leaflet of EVs. We also found that specific ATT isoforms are enriched in EV preparations in respect to total plasma and that those isoforms are selectively associated to EVs when comparing healthy or ATT type II deficient patients. Summary/Conclusion: ATT selective association pat- tern to EVs might be related either to mutations in the primary sequence of the protein or alterations in the glycosylation process, hence experiments are ongoing to reveal the nature of this phenomenon. Our findings suggest that analysis of ATT enriched in EV prepara- tions might be useful to gain insights into the patho- genesis and be of support in the diagnostic algorithm of ATT deficiency. Funding: This work acknowledges FFABR (Fondo finanziamento attività Base di ricerca from MIUR, Ministry of Education, Universities and Research, Italy) for financial support