Search

A one-pot method for the synthesis of uniform Eu3+-doped NaBi(MoO4)2 nanoparticles with an ellipsoidal shape and tetragonal crystal structure functionalized with polyacrylic acid is reported for the first time in the literature. The method is based on a homogeneous precipitation reaction from solutions in an ethylene glycol/water medium containing appropriate bismuth, sodium, and molybdate precursors and polyacrylic acid. The luminescence properties (excitation and emission spectra and luminescence lifetime) of such nanoparticles are evaluated for different Eu3+ doping levels, finding an intense red emission for all synthesized samples. The X-ray attenuation properties of the nanoparticles have been also analyzed, which were found to be better than those of a commercially computed tomography contrast agent (iohexol). The dispersibility of the nanoparticles in a physiological medium was also analyzed, finding that they could be well dispersed in a 2-N-morpholinoethanesulfonic acid monohydrate medium (pH = 6.5). Finally, the cell viability of such a phosphor has been analyzed using MIA-PaCa-2 cells and its in vivo toxicity has been evaluated using the nematode Caenorhabditis elegans model finding no significant toxicity in both cases up to a nanoparticle concentration of 100 μg mL−1, which is within the range required for most in vivo applications. The developed Eu3+-doped NaBi(MoO4)2 nanoparticles are, therefore, excellent candidates for their use as bimodal probes for luminescence imaging and X-ray computed tomography.

Breast cancer accounts for up to 10% of the newly diagnosed cancer cases worldwide, making it the most common cancer found in women. The use of superparamagnetic iron oxide nanoparticles (SPIONs) has been beneficial in the advancement of contrast agents and magnetic hyperthermia (MH) for the diagnosis and treatment of cancers. To achieve delivery of SPIONs to cancer cells, surface functionalization with specific ligands are required. Riboflavin carrier protein (RCP) has been identified as an alternative target for breast cancer cells. Here, we report a novel riboflavin (Rf)-based ligand that provides SPIONs with enhanced colloidal stability and high uptake potential in breast cancer cells. This is achieved by synthesizing an Rf-citrate ligand. The ligand was tested in a multicore SPION system, and affinity to RCP was assessed by isothermal titration calorimetry which showed a specific, entropy-driven binding. MRI and MH responses of the coated Rf-SPIONs were tested to evaluate the suitability of this system as a theranostic platform. Finally, interaction of the Rf-SPIONs with breast cancer cells was evaluated by in vitro cellular uptake in MCF-7 breast cancer cells. The overall characterization of the Rf-SPIONs highlighted the excellent performance of this platform for theranostic applications in breast cancer., This project was supported by Mahidol University under a New Discovery and Frontier Research Grant to K. P. K. This project is funded by National Research Council of Thailand (NRCT) and Mahidol University: N42A650357. Partial support was also provided by a Central Instrument Facility (CIF) grant and the Center for Nanoimaging, Center of Excellence for Innovation in Chemistry (PERCH-CIC), Ministry of Higher Education, Science, Research and Innovation, Faculty of Science, Mahidol University. W. M. was supported by the Science Achievement Scholarship of Thailand. The authors would like to thank Associate Professor Nuttawee Niamsiri, Department of Biotechnology, Faculty of Science, Mahidol University, for the use of the Zetasizer instrument. This research was also funded by the Spanish Government, through the “Severo Ochoa” Programme for Centers of Excellence in R&D (FUNFUTURE, CEX2019-000917 S) and DGA, through the “Fondo Social Europeo” (DGA E15_20R). B. T. H. is grateful for a predoctoral fellowship FPU (FPU19/01311). P. G. acknowledges financial support from the Spanish government (MICIU) through the Ramon y Cajal research program (RyC2019-028414-I).

Nanomedicine has been considered a promising tool for biomedical research and clinical practice in the 21st century because of the great impact nanomaterials could have on human health. The generation of new smart nanomaterials, which enable time- and space-controlled drug delivery, improve the limitations of conventional treatments, such as non-specific targeting, poor biodistribution and permeability. These smart nanomaterials can respond to internal biological stimuli (pH, enzyme expression and redox potential) and/or external stimuli (such as temperature, ultrasound, magnetic field and light) to further the precision of therapies. To this end, photonic and magnetic nanoparticles, such as gold, silver and iron oxide, have been used to increase sensitivity and responsiveness to external stimuli. In this review, we aim to report the main and most recent systems that involve photonic or magnetic nanomaterials for external stimulus-responsive drug release. The uniqueness of this review lies in highlighting the versatility of integrating these materials within different carriers. This leads to enhanced performance in terms of in vitro and in vivo efficacy, stability and toxicity. We also point out the current regulatory challenges for the translation of these systems from the bench to the bedside, as well as the yet unresolved matter regarding the standardization of these materials., The research for this work has received funding from: grant PID2020-118485RB-I00 funded by Ministerio de Ciencia e Innovación/Agencia Estatal de Investigación, the European Union (EU) projects HOTZYMES (grant agreement n° 829162) and PRIME (grant agreement n° 829010) under EU’s Horizon 2020 Programme Research and Innovation actions H2020-FETOPEN-2018-2019-2020-01 and DGA and Fondos Feder (Bionanosurf E15_17R). This research was also supported by CIBER -Consorcio Centro de Investigación Biomédica en Red- (CB06/01/00263), Instituto de Salud Carlos III, Ministerio de Ciencia e Innovación. This research work was also funded by the European Commission – NextGenerationEU (Regulation EU 2020/2094), through CSIC’s Global Health Platform (PTI Salud Global). F.B. also thanks Spanish MINECO project BIO2017-84246-C2-1-R for the FPI grant, G.A. is grateful for the Juan de la Cierva-formación (FJC2020-043450-I) funded by MCIN/AEI/ 10.13039/501100011033 and by “European Union NextGenerationEU/PRTR” and B.T. is grateful for the FPU predoctoral contract (FPU19/01311) from Ministerio de Educación Cultura y Deporte (Spain).

In the last few years, persistent phosphors with a garnet crystal structure have attracted a great deal of interest for a plethora of applications ranging from bioimaging to anti-counterfeiting technologies. However, the development of synthesis methods to fabricate uniform garnet-based micro and nanoparticles, that are needed for such applications, is not mature at all. This study reports the synthesis of highly uniform yttrium aluminum gallium garnet nanospheres. The method is based on homogeneous precipitation in a polyol medium followed by silica coating and calcination. The nanoparticles resulting after silica removal were also uniform and were easily functionalized with polyacrylic acid. The colloidal stability of the latter in physiological media and their biocompatibility were analyzed. The luminescence of the particles, doped with Ce3+, Cr3+, and Nd3+, was studied by recording emission and excitation spectra and persistent luminescence decay curves. Due to their uniform morphology, high colloidal stability, absence of toxicity, and persistent emission in the visible and near-infrared regions, the reported nanospheres show great potential as persistent luminescent bioimaging probes. In addition, the synthesis method paves the way for future use of this persistent material in other applications that require the phosphor to be in the form of highly uniform nanoparticles., This publication is part of the I +D+I Grants RTI2018-094426-B-I00 and PID2020-118485RB-I00 funded by MCIN/AEI/10.13039/501100011033, by “ERDF A way of making Europe”, and the Fondo Social de la DGA (grupos DGA). Financial support was also provided by Junta de Andalucía (P20_00182). Grants FPU19/00527 and FPU19/01311 were funded by MCIN/AEI/10.13039/501100011033 and by “ESF Investing in your future”. This research work was performed in the framework of the Nanomedicine CSIC HUB (Ref. 202180E048).