Inulin coated plasmonic gold nanoparticles as a tumor-selective tool for cancer therapy

Polymer coated gold nanospheres are proposed as a tumor selective carrier for the anticancer drug doxorubicin. Thiolated polyethyleneglycol (PEG-SH) and an inulin-amino derivative based copolymer (INU-EDA) were used as stabilizing and coating materials for 40 nm gold nanospheres. The resulting polymer coated gold nanospheres (Au@PEG-INU) showed excellent physicochemical stability and potential stealth like behavior. The system was loaded with doxorubicin (Au@PEG-INU/Doxo) and its cytotoxicity profile was evaluated on human cervical cancer cells (HeLa) and lung cancer cells (A549), as compared to Au@PEG-INU and doxorubicin alone. Cytotoxicity assays showed that the system is able to drastically reduce cell viability upon incubation for 3 days. This result was supported by the ability of Au@PEG-INU/Doxo to be internalized by cancer cells and to release doxorubicin, as assessed by fluorescence microscopy. Finally, a cancer/non cancer cell co-culture model was used to display the advantageous therapeutic effects of the proposed system with respect to doxorubicin alone, thereby demonstrating the ability of Au@PEG-INU/Doxo to preferentially accumulate in tumor cells due to their enhanced metabolism, and to selectively kill target cells

Antibonding plasmon modes in colloidal gold nanorod clusters

The optical response of nanoplasmonic colloids in disperse phase is strictly related to their shape.However, upon self-assembly, new optical features, for example, bonding or antibonding modes, emerge as a result of the mutual orientations of nanoparticles. The geometry of the final assemblies often determines which mode is dominating in the overall optical response. These new plasmon modes, however, are mostly observed in silico, as self-assembly in the liquid phase leads to cluster formation with a broad range of particle units. Here we show that low-symmetry clustering of gold nanorods (AuNRs) in solution can also reveal antibonding modes. We found that UVlight irradiation of colloidal dispersions of AuNRs in N-methyl-2-pyrrolidone (NMP), stabilized by poly(vinylpyrrolidone) (PVP) results in the creation of AuNRs clusters with ladderlike morphology, where antibonding modes can be identified. We propose that UV irradiation induces formation of radicals in solvent molecules, which then promote cross-linking of PVP chains on the surface of adjacent particles. This picture opens up a number of relevant questions in nanoscience and is expected to find application in light induced self-assembly of particles with various compositions and morphologies

Detection of amyloid fibrils in Parkinson's disease using plasmonic chirality

Las fibrillas amiloides, que están estrechamente asociadas con varias enfermedades neurodegenerativas, son los productos finales de muchas vías de agregación de proteínas. Por lo tanto, la identificación de las fibrillas en baja concentración es fundamental para el diagnóstico de las enfermedades y el desarrollo de estrategias terapéuticas. Informamos de una metodología para la identificación específica de las fibrillas amiloides mediante efectos quiroprácticos en nanopartículas plasmónicas. La formación de las fibrillas amiloides basadas en α-sinucleína fue probada utilizando nanorodos de oro, que no mostraron ninguna interacción aparente con las proteínas monoméricas, pero sí una efectiva adsorción a las estructuras fibrilares mediante interacciones no covalentes. La estructura amiloide impulsa una disposición helicoidal de los nanorodios, lo que da lugar a una intensa actividad óptica en las longitudes de onda de resonancia del plasmón de la superficie. Esta técnica de detección se aplicó con éxito a los homogeneizados del cerebro humano de los pacientes afectados por la enfermedad de Parkinson, en los que se identificaron las fibrillas proteínicas relacionadas con la enfermedad mediante señales quirales de nanorodos de Au en el infrarrojo visible y cercano, mientras que las muestras de cerebro sano no mostraron ninguna actividad óptica significativa. La técnica se amplió además a la detección específica de amiloides infecciosos formados por proteínas priónicas, confirmando así el amplio potencial de la técnica. La intensa respuesta quiral impulsada por un fuerte acoplamiento dipolar en arreglos helicoidales de Au nanorod nos permitió detectar fibrillas amiloides hasta concentraciones nanomolares.Amyloid fibrils, which are closely associated with various neurodegenerative diseases, are the final products in many protein aggregation pathways. The identification of fibrils at low concentration is, therefore, pivotal in disease diagnosis and development of therapeutic strategies. We report a methodology for the specific identification of amyloid fibrils using chiroptical effects in plasmonic nanoparticles. The formation of amyloid fibrils based on α-synuclein was probed using gold nanorods, which showed no apparent interaction with monomeric proteins but effective adsorption onto fibril structures via noncovalent interactions. The amyloid structure drives a helical nanorod arrangement, resulting in intense optical activity at the surface plasmon resonance wavelengths. This sensing technique was successfully applied to human brain homogenates of patients affected by Parkinson’s disease, wherein protein fibrils related to the disease were identified through chiral signals from Au nanorods in the visible and near IR, whereas healthy brain samples did not exhibit any meaningful optical activity. The technique was additionally extended to the specific detection of infectious amyloids formed by prion proteins, thereby confirming the wide potential of the technique. The intense chiral response driven by strong dipolar coupling in helical Au nanorod arrangements allowed us to detect amyloid fibrils down to nanomolar concentrations.• Comisión Europea. Programa Marie Sklodowska-Curie. Proyecto H2020-MSCA-IF-2015_708321, para Jatish Kumar • Consejo Europeo de Investigación. Proyectos 335078 COLOURATOM y 648071 ProNANO, para Sara • • Comisión Europea. Programa Marie Sklodowska-Curie. Proyecto H2020-MSCA-IF-2015_708321, para Jatish Kumar • Consejo Europeo de Investigación. Proyectos 335078 COLOURATOM y 648071 ProNANO, para Bals y Aitziber López Cortajarena • Comisión Europea. Proyecto EUSMI 731019, para Sara Bals y Luis Manuel Liz Marzán • Ministerio de Economía y Competitividad. Proyectos MAT2013-46101-R, AGL2015-65046-C2-1-R, y BIO2016-77367-C2-1-R, para Aitziber López Cortajarena, Joaquín Castilla Castrillón y Luis Manuel Liz MarzánpeerReviewe

Anisotropic nanoparticles: General discussion

35si-reservedmixedCastelli, Andrea; Striolo, Alberto; Roig, Anna; Murphy, Catherine; Reguera, Javier; Liz-Marzán, Luis; Mueller, Axel; Critchley, Kevin; Zhou, Yu; Brust, Mathias; Thill, Antoine; Scarabelli, Leonardo; Tadiello, Luciano; König, Tobias A. F.; Reiser, Beate; López-Quintela, M. Arturo; Buzza, Martin; Deák, András; Kuttner, Christian; Gonzalez Solveyra, Estefania; Pasquato, Lucia; Portehault, David; Mattoussi, Hedi; Kotov, Nicholas A.; Kumacheva, Eugenia; Heatley, Kelley; Bergueiro, Julian; González, Guillermo; Tong, Wenming; Tahir, Muhammad Nawaz; Abécassis, Benjamin; Rojas-Carrillo, Oscar; Xia, Younan; Mayer, Martin; Peddis, DavideCastelli, Andrea; Striolo, Alberto; Roig, Anna; Murphy, Catherine; Reguera, Javier; Liz-Marzán, Luis; Mueller, Axel; Critchley, Kevin; Zhou, Yu; Brust, Mathias; Thill, Antoine; Scarabelli, Leonardo; Tadiello, Luciano; König, Tobias A. F.; Reiser, Beate; López-Quintela, M. Arturo; Buzza, Martin; Deák, András; Kuttner, Christian; Gonzalez Solveyra, Estefania; Pasquato, Lucia; Portehault, David; Mattoussi, Hedi; Kotov, Nicholas A.; Kumacheva, Eugenia; Heatley, Kelley; Bergueiro, Julian; González, Guillermo; Tong, Wenming; Tahir, Muhammad Nawaz; Abécassis, Benjamin; Rojas-Carrillo, Oscar; Xia, Younan; Mayer, Martin; Peddis, David

Nanoscience and Nanotechnology Cross Borders

The recent ExecutiveOrder by President Trump attempting to ban temporarily the citizens of seven countries (Iran, Iraq, Libya, Somalia, Sudan, Syria, and Yemen) from entering the United States is having significant consequences within the country and around the world. The Order poses a threat to the health and vitality of science, barring students and scientists from these countries from traveling to the United States to study or to attend conferences. In preventing those members of the international scientific community from traveling beyond U.S. borders without guaranteed safe return, the Executive Order demeans them; in so doing, it demeans us all. Universities and research communities are especially impacted, as major universities have students and often faculty holding passports from one of these seven countries. This temporary ban would affect refugees fleeing war-torn areas, challenging the long-standing notion that the United States is a safe haven for those fleeing persecution and war in addition to being a magnet for talent from every corner of the world. The pages of this journal reflect the geographic, ethnic, and cultural diversity that underpins great science. The ban impacts domestic and global scientific efforts and communities. Science succeeds through the cooperation between collections of individuals and teams around the world discovering and learning from each other. To ensure rapid scientific progress, open communication and exchange between scientists are essential. As scientists, engineers, and clinicians, we have benefited from open interactions and collaborations with visitors and students from all parts of the world as well as through scientific publications and discussions at scientific meetings