ABSTRACT Introduction: This paper focuses on the synthesis, physicochemical characterization, bioactivity evaluation, and innovative applications of new biohybrid nanomaterials. Sepiolite is a nanofibrous natural silicate that represents a very attractive nanocarrier for nucleic acids delivery into cells, among other innovative applications in life sciences and biotechnology. Methods: The physicochemical characterization and the bioactivity evaluation of biohybrids were performed using advanced techniques and procedures, including AFM, TEM, Confocal Microscopy, TLVM, FTIR, Z-potential measurements, UV-vis, FACS, Western blot, RT-qPCR, among others. Results: New biohybrids were obtained, based on the assembly of nucleic acids with sepiolite nanofibers. The mechanisms of cell internalization and response to sepiolite exposure were proposed. We demonstrated that sepiolite is a promising nanocarrier for the non-viral and stable transfer of plasmid DNA into bacteria, mammalian and human cells, with an optimized efficiency. Due to its ability to bind various biomolecules, sepiolite could be used as a nanocarrier for the simultaneous vectorization of diverse biological molecules, including proteins, nucleases and antibodies. In addition, we obtain new protocols for both, strongly improving bacterial transformation efficiency, and to extract plasmids from bacteria, in a rapid, convenient and inexpensive method that doesn't require competent cell preparation, representing an advantageous alternative to onerous commercial kits. As a conclusion, Because of the low cost of sepiolite, its low toxicity, its natural fluorescence, the ease and convenience of sepiolite/DNA synthesis methods, the possibilities of improving the transfection efficiency and additional enticing future developments, sepiolite represents a very attractive nanoplatform for potential applications in nanomedicine and nanobiotechnology.

RESUMEN Introducción: Este trabajo se centró en la síntesis, caracterización físicoquímica, evaluación de su bioactividad y aplicaciones biomédicas de nuevos nanomateriales biohíbridos. La sepiolita es un silicato natural nanofibroso que presenta atractivas características como nanoportador para la liberación de ácidos nucleicos en células, entre otras aplicaciones innovadoras en el área de las ciencias de la vida y de la biotecnología. Métodos: La caracterización físico-química y evaluación biológica de los biohíbridos fue realizada usando procedimientos y técnicas novedosas, incluyendo entre otras AFM, TEM, microscopía confocal, TLVM, FTIR, Potencial Zeta, UV-vis, FACS, Western-blot, RT- qPCR. Resultados: Se obtuvieron nuevos biohíbridos mediante ensamblado de ácidos nucleicos con nanofibras de sepiolita. Se propusieron sus mecanismos de internalización y respuesta celular. Demostramos que la sepiolita es un nanoportador prometedor para la transferencia estable no-viral de ADN plasmídico en bacterias, células de mamíferos y humanas, con eficiencia optimizada. Debido a su capacidad de anclar varias biomoléculas, la sepiolita constituye también un nanoportador para la vectorización simultánea de diferentes moléculas biológicas, incluyendo proteínas, nucleasas y anticuerpos. Adicionalmente, obtuvimos nuevos protocolos para aumentar significativamente la eficiencia de transformación bacterial, y para la extracción de ADN de bacterias, mediante métodos rápidos, seguros y económicos que no requieren la preparación de células competentes, representando una ventajosa alternativa a los costosos kits comerciales. En conclusión, la sepiolita es un producto de bajo costo, baja toxicidad y fluorescencia natural, con facilidad y conveniencia en métodos de síntesis de biohíbridos sepiolita/ADN, con posibilidad de aumentar su eficiencia de transfección, que junto a potenciales desarrollos futuros, representa una atractiva nanoplataforma para aplicaciones en nanomedicina y nanobiotecnología.

Este trabalho relata um estudo sistemático do comportamento estrutural e elétrico de três fases ternárias do sistema Ta xMo1-xS2 (x = 0,55, 0,75 e 0,90) e de seus compostos de intercalação resultantes das inserções química e eletroquímica de lítio, assim como das intercalações de piridina e poli(óxido de etileno). As três fases foram preparadas pela reação direta de seus elementos constituintes, sem qualquer outro aditivo, a 900 ºC em atmosfera inerte. Os compostos resultantes foram caracterizados por meio de difratometria de raios X de pó (XRD), análises termogravimétrica e térmica diferencial (TGA/DTA), fluorescência de raios X por dispersão de energia (EDX) e microscopia eletrônica de varredura com emissão de campo (FE-SEM). A condutividade elétrica dos diferentes compostos preparados foi medida no intervalo de temperatura 1,5-300 K utilizando o método convencional de sonda de quatro pontas van der Pauw na presença de um campo magnético de 9 T para verificar a ocorrência do fenômeno de magnetoresistividade.

This work reports a systematic study of the structural and electrical behavior of three ternary phases of the Ta xMo1-xS2 system (x = 0.55, 0.75 and 0.90) and their intercalation compounds resulting from both chemical and electrochemical lithium insertions, as well as from pyridine and poly(ethylene oxide) intercalations. The three ternary phases were prepared by direct reaction of their constituting elements, without any other additive, at 900 ºC in inert atmosphere. The resulting compounds were characterized by means of X-ray powder diffractometry (XRD), thermogravimetric and differential thermal (TGA/DTA) analyses, energy dispersive X-ray fluorescence (EDX) and field emission-scanning electron microscopy (FE-SEM). The electrical conductivity of the different products was measured in the 1.5-300 K temperature range using the conventional four probe van der Pauw method in the presence of a 9 T magnetic field in order to verify the occurrence of magnetoresistivity phenomena.