Nanoparticles for Multimodal Antivascular Therapeutics: Dual Drug Release, Photothermal and Photodynamic Therapy.

The poor delivery of nanoparticles to target cancer cells hinders their success in the clinical setting. In this work, an alternative target readily available for circulating nanoparticles has been selected to eliminate the need for nanoparticle penetration in the tissue: the tumor blood vessels. A tumor endothelium-targeted nanoparticle (employing an RGD-containing peptide) capable of co-delivering two anti-vascular drugs (one anti-angiogenic drug and one vascular disruption agent) is here presented. Furthermore, the nanodevice presents two additional anti-vascular capabilities upon activation by Near-Infrared light: provoking local hyperthermia (by gold nanorods in the system) and generating toxic reactive oxygen species (by the presence of a photosensitizer). RGD-targeting is shown to increase uptake by HUVEC cells, and while the nanoparticles are shown not to be toxic for these cells, upon Near-Infrared irradiation their almost complete killing is achieved. The combination of all four therapeutic modalities is then evaluated in an ex ovo fibrosarcoma xenograft model, which shows a significant reduction in the number of blood vessels irrigating the xenografts when the nanoparticles are present, as well as the destruction of the existing blood vessels upon irradiation. These results suggest that the combination of different anti-vascular therapeutic strategies in a single nanocarrier appears promising and should be further explored in the future

Reversible nanogate system for Mesoporous Silica Nanoparticles based on Diels-Alder adducts.

The implementation of nanoparticles as nanomedicines require from sophisticated surface modifications in order to reduce immune response and enhance recognition abilities. In addition to that, Mesoporous Silica nanoparticles present extraordinary host-guest abilities and facile surface functionalization. These two factors make them ideal candidates for the development of novel drug delivery systems, at the expense of increasing the structural complexity. With this idea in mind, a system of triggerable and tunable silica nanoparticles was developed for its application as drug delivery nanocarriers. For that purpose, Diels-Alder cycloaddition adducts were chosen as thermalresponsive units; that permitted to bind Au nanocaps able to block the pores and allow the incorporation of targeting fragments. The capping efficiency was tested under different thermal conditions, obtaining outstanding efficiencies within the physiological range and mild temperatures, as well as enhanced releases under pulsing heating cycles which showed the best release profiles

Biogenic synthesis of metal nanoparticles using a biosurfactant extracted from corn and their antimicrobial properties

A new and promising biosurfactant extracted from corn steep liquor has been used for the green synthesis of gold and silver nanoparticles (NPs) in a one-step procedure induced by temperature. Most of the biosurfactants proposed in the literature are produced by pathogenic microorganisms; whereas the biosurfactant used in the current work was extracted from a liquid stream, fermented spontaneously by lactic acid bacteria, which are generally recognized as safe (GRAS) microorganisms. The reduction of a gold precursor in the presence of a biosurfactant gives rise to a mixture of nanospheres and nanoplates with distinct optical features. Moreover, the growth of nanoplates can be promoted by increasing the reaction temperature to 60 °C. In the case of silver, the biosurfactant just induces the formation of pseudo-spherical NPs. The biosurfactant plays a key role in the reduction of the metal precursor, as well as in the stabilization of the resulting NPs. Furthermore, the antimicrobial activity of the resulting silver colloids has been analyzed against Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. The biosurfactant stabilized NPs slightly increased the inhibition of E. coli in comparison with citrate stabilized Ag NPs. The use of this biosurfactant extracted from corn steep liquor for the synthesis of metal NPs contributes to enhancing the application of green technologies and increasing the utilization of clean, non-toxic and environmentally safe production processes. Therefore, it can help to reduce environmental impact, minimize waste and increase energy efficiency in the field of nanomaterials.This work was supported by the Spanish MINECO (MAT2013-45168-R and MAT2016-77809-R) and Fundación Ramón Areces. Also, Xanel Vecino gratefully acknowledges her post-doctoral grant (SFRH/BPD/101476/2014) supported by the Portuguese Foundation for Science and Technology (FCT, Portugal).info:eu-repo/semantics/publishedVersio

Targeted Chemo‐Photothermal Therapy: A Nanomedicine Approximation to Selective Melanoma Treatment

RESEARCHER ID L-2250-2014 (Gonzalo Villaverde Cantizano) ORCID 0000-0003-2065-0417 (Gonzalo Villaverde Cantizano) RESEARCHER ID G-7562-2016 (Sergio Gómez Graña) ORCID 0000-0002-7736-051X (Sergio Gómez Graña) RESEARCHER ID E-8300-2012 (Eduardo Guisasola Cal) ORCID 0000-0002-2549-1745 (Eduardo Guisasola Cal) RESEARCHER ID K-8193-2014 (Alejandro Baeza) ORCID 0000-0002-2026-6266 (Alejandro Baeza) RESEARCHER ID M-3378-2014 (María Vallet Regí) ORCID 0000-0002-6104-4889 (María Vallet Regí)Melanoma is one of the most severe public health issues worldwide, not onlybecause of the high number of cases but also for its poor prognosis in late stages. Therefore, early diagnosis and efficient treatment are key toward a future solution. However, melanoma is highly resistant to cytotoxicity in its metastatic form. In this context, we propose a therapeutic strategy based on a targeted chemo-photothermal nanotransporter for cytotoxic compounds. This approach comprises the use of core-multishell gold nanorods, coated with mesoporous silica and further covered with a thermosensitive polymer, which is vectorized for selective internalization in melanoma cells. The proposed nanoformulation is capable of releasing the transported cytotoxic compounds on demand, in response to near-IR irradiation, with high selectivity and efficacy against malignant cells, even at low concentrations, thereby providing a new tool against melanoma disease.Depto. de Química en Ciencias FarmacéuticasFac. de FarmaciaTRUEUnión Europea. H2020Ministerio de Economía y Competitividad (MINECO)pu

Plasmonic supercrystals

For decades, plasmonic nanoparticles have been extensively studied due to their extraordinary properties, related to localized surface plasmon resonances. A milestone in the field has been the development of the so-called seed-mediated growth method, a synthetic route that provided access to an extraordinary diversity of metal nanoparticles with tailored size, geometry and composition. Such a morphological control came along with an exquisite definition of the optical response of plasmonic nanoparticles, thereby increasing their prospects for implementation in various fields. The susceptibility of surface plasmons to respond to small changes in the surrounding medium or to perturb (enhance/quench) optical processes in nearby molecules, has been exploited for a wide range of applications, from biomedicine to energy harvesting. However, the possibilities offered by plasmonic nanoparticles can be expanded even further by their careful assembly into either disordered or ordered structures, in 2D and 3D. The assembly of plasmonic nanoparticles gives rise to coupling/hybridization effects, which are strongly dependent on interparticle spacing and orientation, generating extremely high electric fields (hot spots), confined at interparticle gaps. Thus, the use of plasmonic nanoparticle assemblies as optical sensors have led to improving the limits of detection for a wide variety of (bio)molecules and ions. Importantly, in the case of highly ordered plasmonic arrays, other novel and unique optical effects can be generated. Indeed, new functional materials have been developed via the assembly of nanoparticles into highly ordered architectures, ranging from thin films (2D) to colloidal crystals or supercrystals (3D). The progress in the design and fabrication of 3D supercrystals could pave the way toward next generation plasmonic sensors, photocatalysts, optomagnetic components, metamaterials, etc. In this Account, we summarize selected recent advancements in the field of highly ordered 3D plasmonic superlattices. We first analyze their fascinating optical properties for various systems with increasing degrees of complexity, from an individual metal nanoparticle through particle clusters with low coordination numbers to disordered self-assembled structures and finally to supercrystals. We then describe recent progress in the fabrication of 3D plasmonic supercrystals, focusing on specific strategies but without delving into the forces governing the self-assembly process. In the last section, we provide an overview of the potential applications of plasmonic supercrystals, with a particular emphasis on those related to surface-enhanced Raman scattering (SERS) sensing, followed by a brief highlight of the main conclusions and remaining challenges.Agencia Estatal de Investigación | Ref. MAT2017-86659-RMinisterio de Economía, Industria y Competitividad | Ref. MAT2016-77809-

Integrating plasmonic supercrystals in microfluidics for ultrasensitive, label-free, and selective surface-enhanced raman spectroscopy detection

Surface-enhanced Raman spectroscopy (SERS) microfluidic chips for label-free and ultrasensitive detection are fabricated by integrating a plasmonic supercrystal within microfluidic channels. This plasmonic platform allows the uniform infiltration of the analytes within the supercrystal, reaching the so-called hot spots. Moreover, state-of-the-art simulations performed using large-scale supercrystal models demonstrate that the excellent SERS response is due to the hierarchical nanoparticle organization, the interparticle separation (IPS), and the presence of supercrystal defects. Proof-of-concept experiments confirm the outstanding performance of the microfluidic chips for the ultradetection of (bio)molecules with no metal affinity. In fact, a limit of detection (LOD) as low as 10–19 M was reached for crystal violet. The SERS microfluidic chips show excellent sensitivity in the direct analysis of pyocyanin secreted by Pseudomonas aeruginosa grown in a liquid culture medium. Finally, the further integration of a silica-based column in the plasmonic microchip provides charge-selective SERS capabilities as demonstrated for a mixture of positively and negatively charged molecules.Agencia Estatal de Investigación | Ref. TEC2017-85376-C2-1-RAgencia Estatal de Investigación | Ref. TEC2017-85376-C2-2-RXunta de Galicia | Ref. GRC ED431C 2016−486 048Gobierno de Extremadura | Ref. IB18073Agencia Estatal de Investigación | Ref. IJCI-2016-2910

Polydimethylsiloxane Sponge-Supported Metal Nanoparticles as Reusable Catalyst for Continuous Flow Reactions

In this manuscript, polydimethylsiloxane (PDMS) sponges supporting metal nanoparticles (gold and palladium) were developed and their catalytic properties were studied through a model reaction such as the hydrogenation of p-nitrophenol. Different synthetic conditions for gold and palladium were studied to obtain the best catalyst in terms of nanoparticle loading. The as-prepared catalysts were characterized by different techniques such as scanning electron microscopy (SEM) and inductively coupled plasma optical emission spectroscopy (ICP-OES). The catalytic efficiency and recyclability of the supported catalyst were tested in static conditions. In addition, thanks to the porous structure of the material where the catalytic centers (metal nanoparticles) are located, the model reaction for continuous flow systems was tested, passing the reaction components through the catalyst, observing a high efficiency and recyclability for these systems

Nanomaterials and Nanostructures Hand-In-Hand with Biology

The nanoparticle’s synthesis had its tipping point at the beginning of the 21st century, opening up the possibility of manufacturing nanoparticles with almost every imaginable shape and size [...

Polydimethylsiloxane sponge-supported metal nanoparticles as reusable catalyst for continuous flow reactions

In this manuscript, polydimethylsiloxane (PDMS) sponges supporting metal nanoparticles (gold and palladium) were developed and their catalytic properties were studied through a model reaction such as the hydrogenation of p-nitrophenol. Different synthetic conditions for gold and palladium were studied to obtain the best catalyst in terms of nanoparticle loading. The as-prepared catalysts were characterized by different techniques such as scanning electron microscopy (SEM) and inductively coupled plasma optical emission spectroscopy (ICP-OES). The catalytic efficiency and recyclability of the supported catalyst were tested in static conditions. In addition, thanks to the porous structure of the material where the catalytic centers (metal nanoparticles) are located, the model reaction for continuous flow systems was tested, passing the reaction components through the catalyst, observing a high efficiency and recyclability for these systems.Xunta de Galicia | Ref. EXCELENCIA-ED431F 2021/05Xunta de Galicia | Ref. GRC ED431C2020/09Ministerio de Ciencia e innovación | Ref. PID2020-117371RA-I00Ministerio de Ciencia e innovación | Ref. PID2019-108954RB-I0

Cyclodextrins and inorganic nanoparticles: another tale of synergy

In this review, we summarize the recent research focused on the combination of inorganic nanoparticles and α-, β- and γ- cyclodextrins. Our intention is to highlight the most relevant publications on the synthesis of nanoparticle-cyclodextrin (NP-CD) nanohybrids, with CDs acting as reducing agents or through the post-synthetic modification of inorganic nanoparticles with CDs. We also discuss the new or enhanced properties that arise from the host-guest capabilities of the CDs and inorganic nanoparticles. Finally, we illustrate the potential applications of these materials in numerous research fields.Ministerio de Economía, Industria y Competitividad | Ref. MAT2016-77809-RAgencia Estatal de Investigación | Ref. PID2019-108954RB-I00Agencia Estatal de Investigación | Ref. FJCI-2016-2910