New opportunities for light-based tumor treatment with an “iron fist”

The efficacy of photodynamic treatments of tumors can be significantly improved by using a new generation of nanoparticles that take advantage of the unique properties of the tumor microenvironmen

Quo vadis, nanoparticle-enabled in vivo fluorescence imaging?

The exciting advancements that we are currently witnessing in terms of novel materials and synthesis approaches are leading to the development of colloidal nanoparticles (NPs) with increasingly greater tunable properties. We have now reached a point where it is possible to synthesize colloidal NPs with functionalities tailored to specific societal demands. The impact of this new wave of colloidal NPs has been especially important in the field of biomedicine. In that vein, luminescent NPs with improved brightness and near-infrared working capabilities have turned out to be optimal optical probes that are capable of fast and high-resolution in vivo imaging. However, luminescent NPs have thus far only reached a limited portion of their potential. Although we believe that the best is yet to come, the future might not be as bright as some of us think (and have hoped!). In particular, translation of NP-based fluorescence imaging from preclinical studies to clinics is not straightforward. In this Perspective, we provide a critical assessment and highlight promising research avenues based on the latest advances in the fields of luminescent NPs and imaging technologies. The disillusioned outlook we proffer herein might sound pessimistic at first, but we consider it necessary to avoid pursuing "pipe dreams"and redirect the efforts toward achievable - yet ambitious - goalsThis work has been cofinanced by European Structural and Investment Fund and by the European Union’s Horizon 2020 FET Open program under grant agreement no. 801305 (NanoTBTech). E.X. is grateful for a Juan de la Cierva Formacion scholarship (FJC2018-036734-I). A.B. acknowl- ́ edges funding from Comunidad de Madrid through TALENTO grant ref. 2019-T1/IND-14014. D.

Less is more: dimensionality reduction as a general strategy for more precise luminescence thermometry

Thermal resolution (also referred to as temperature uncertainty) establishes the minimum discernible temperature change sensed by luminescent thermometers and is a key figure of merit to rank them. Much has been done to minimize its value via probe optimization and correction of readout artifacts, but little effort was put into a better exploitation of calibration datasets. In this context, this work aims at providing a new perspective on the definition of luminescence-based thermometric parameters using dimensionality reduction techniques that emerged in the last years. The application of linear (Principal Component Analysis) and non-linear (t-distributed Stochastic Neighbor Embedding) transformations to the calibration datasets obtained from rare-earth nanoparticles and semiconductor nanocrystals resulted in an improvement in thermal resolution compared to the more classical intensity-based and ratiometric approaches. This, in turn, enabled precise monitoring of temperature changes smaller than 0.1 °C. The methods here presented allow choosing superior thermometric parameters compared to the more classical ones, pushing the performance of luminescent thermometers close to the experimentally achievable limits.publishe

Avoiding induced heating in optical trap

Paloma Rodríguez-Sevilla, Yuhai Zhang, Patricia Haro-González, Francisco Sanz-Rodríguez, Francisco Jaque, José García Sole, Xiaogang Liu, Daniel Jaque, "Avoiding induced heating in optical trap", Optical Trapping and Optical Micromanipulation XIV, Proc. SPIE 10347 - 1034716 (25 August 2017); doi: 10.1117/12.2276355. ne print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited.Proceedings of XIV Optical Trapping and Optical Micromanipulation Conference (San Diego, California, United States)Luminescence of a single upconverting particle (NaYF 4 :Er 3+ ,Yb 3+ ) can be used to determine the optical trap temperature due to the partial absorption of the trapping beam either by the medium (water) or the optically trapped particle itself. This fact is an important drawback can be reduced by shifting the trapping wavelength out of the water absorption band, or by using time-modulated laser trapping beams. Both approaches have been studied and the results have shown that the thermal loading due to the trapping radiation can be minimized.This work was supported by the Spanish Ministerio de Educación y Ciencia (MAT2016-75362-C3-1-R) and by COST Action 1403. P.H.G. thanks the Spanish Ministerio de Economía y Competitividad (MINECO) for the Juan de la Cierva- Incorporación program. P.R.S. thanks MINECO and the Fondo Social Europeo (FSE) for the “Promoción del talento y su Empleabilidad en I+D+i” statal program (BES-2014-069410

In Vivo Spectral Distortions of Infrared Luminescent Nanothermometers Compromise Their Reliability

“This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Nano, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see: https://pubs.acs.org/doi/full/10.1021/acsnano.9b08824Luminescence nanothermometry has emerged over the past decade as an exciting field of research due to its potential applications where conventional methods have demonstrated to be ineffective. Preclinical research has been one of the areas that have benefited the most from the innovations proposed in the field. Nevertheless, certain questions concerning the reliability of the technique under in vivo conditions have been continuously overlooked by most of the scientific community. In this proof-of-concept, hyperspectral in vivo imaging is used to explain how unverified assumptions about the thermal dependence of the optical transmittance of biological tissues in the so-called biological windows can lead to erroneous measurements of temperature. Furthermore, the natural steps that should be taken in the future for a reliable in vivo luminescence nanothermometry are discussed together with a perspective view of the field after the findings here reportedThis work was supported by the Spanish Ministry of Economy and Competitiveness under projects MAT2016-75362-C3-1-R, MAT2017-83111R, and MAT2017-85617-R, by the Instituto de Salud Carlos III (PI16/00812), and by the Comunidad Autónoma de Madrid (B2017/BMD-3867RENIMCM) and cofinanced by the European Structural and investment fund. Additional funding was provided by the European Union’s Horizon 2020 FET Open programme (grant agreement No 801305), the Fundación para la Investigación Biomédica del Hospital Universitario Ramón y Cajal project IMP18_38 (2018/0265), and also COST action CA17140. Y. Shen acknowledges a scholarship from the China Scholarship Council (No. 201806870023

Thermal loading in flow-through electroporation microfluidic devices

Thermal loading effects in flow-through electroporation microfluidic devices have been systematically investigated by using dye-based ratiometric luminescence thermometry. Fluorescence measurements have revealed the crucial role played by both the applied electric field and flow rate on the induced temperature increments at the electroporation sections of the devices. It has been found that Joule heating could raise the intra-channel temperature up to cytotoxic levels (>45 °C) only when conditions of low flow rates and high applied voltages are applied. Nevertheless, when flow rates and electric fields are set to those used in real electroporation experiments we have found that local heating is not larger than a few degrees, i.e. temperature is kept within the safe range (<32 °C). We also provide thermal images of electroporation devices from which the heat affected area can be elucidated. Experimental data have been found to be in excellent agreement with numerical simulations that have also revealed the presence of a non-homogeneous temperature distribution along the electroporation channel whose magnitude is critically dependent on both applied electric field and flow rate. Results included in this work will allow for full control over the electroporation conditions in flow-through microfluidic devicesThis work has been supported by NSF (CBET 1016547, 1041834, 0967069), the Universidad Autónoma de Madrid and Comunidad Autónoma de Madrid (Project S2009/MAT-1756), and the Spanish Ministerio de Educación y Ciencia (MAT2010-16161). Blanca del Rosal thanks Universidad Autónoma de Madrid for financial support (FPI-UAM grant

Diferencias por sexo en bateria III aprov entre estudiantes chilenos: Estudio de validez de la bateria III aprov de Woodcock y Munoz

54 p.El objetivo general de la presente memoria es la validación y adaptación de la Batería III Woodcock-Muñoz, instrumento de evaluación sustentado en la Teoría C-H-C de Cattell, Horn y Carroll, y cuyo estudio se centró en su parte de aprovechamiento escolar. Además, busca identificar la existencia o no, de diferencias significativas entre hombres y mujeres respecto del aprovechamiento, sobre una muestra chilena compuesta de 241 estudiantes, estratificada por sexo, nivel socioeconómico y grado de escolaridad. Esta memoria reporta que 15 de las 17 pruebas de aprovechamiento de la Batería III, alcanzaron valores superiores al límite inferior de una confiabilidad aceptable. A través del método de extracción de factores de ejes principales con rotación oblimin para el análisis de las pruebas del instrumento, se obtuvieron 2 factores que explican el 76, 78% de la varianza con un muy buen nivel de ajuste (KMO =0,961; χ2=5231,99; gl=136; p<0,001). Un primer factor explica un 69,1% de la varianza denominándose “Factor General de Aprovechamiento”, y el segundo explica un 7,6%. Al compararse aprovechamiento escolar y sexo, en el área curricular “Lenguaje Escrito” (t=-2,58; gl=239; p=0,01), las niñas obtuvieron un mayor rendimiento. Respecto de las pruebas evaluadas, se observó que en “Muestras de Redacción” (t=-2,79; gl=239; p=0.006), “Ortografía” (t=-2,53; gl=239; p=0.012) y “Fluidez en la Escritura” (t=-2,29; gl=239; p=0,022), las niñas manifiestan un mejor desempeño que los niños

Neodymium-doped nanoparticles for infrared fluorescence bioimaging: The role of the host

Artículo escrito por un elevado número de autores, solo se referencian el que aparece en primer lugar, el nombre del grupo de colaboración, si le hubiere, y los autores pertenecientes a la UAMThe spectroscopic properties of different infrared-emitting neodymium-doped nanoparticles (LaF3:Nd3+, SrF2:Nd3+, NaGdF4: Nd3+, NaYF4: Nd3+, KYF4: Nd3+, GdVO4: Nd3+, and Nd:YAG) have been systematically analyzed. A comparison of the spectral shapes of both emission and absorption spectra is presented, from which the relevant role played by the host matrix is evidenced. The lack of a "universal" optimum system for infrared bioimaging is discussed, as the specific bioimaging application and the experimental setup for infrared imaging determine the neodymium-doped nanoparticle to be preferentially used in each caseThis project has been supported by the Spanish Ministerio de Economıa y Competitividad under Project No. MAT2013- 47395-C4-1-R. B. del Rosal thanks Universidad Autónoma de Madrid for an FPI grant. M. Misiak and A. Bednarkiewicz acknowledge the support from POIG.01.01.02-02-002/08 project financed by the European Regional Development Fund (Operational Programme Innovative Economy, 1.1.2). Yu. Orlovskii and A. Vanetsev acknowledge the support from the Centre of Excellence TK114 “Mesosystems: Theory and Applications”; TK117 “High-Technology Materials for Sustainable Development” and European Social Fund, Project No. #MTT50. Dragana Jovanovic and Miroslav Dramicanin acknowledge financial support of the Ministry of Education, Science and Technological development of the Republic of Serbia (Grant No. 45020). The authors are grateful to G. Drazic for TEM measurements of GdVO4 nanoparticles. The authors also thank the Brazilian agencies FAPEAL-Fundacao de Amparo a Pesquisa do Estado de Alagoas (Project No. PRONEX 2009-09-006), FINEP (Financiadora de Estudos e Projetos), CNPq (Conselho Nacional de Desenvolvimento Cientıfico e Tecnologico) through Grant INCT NANO(BIO)SIMES, and D. Jaque (Pesquisador Visitante Especial (PVE)-CAPES) thanks CAPES (Coordenadoria de Aperfeic¸oamento de Pessoal de Ensino Superior) for the Project PVE No. A077/2013. K.U.K. is a Postdoctoral fellow of the Project PVE A077/2013. E. Navarro is funded by National Council for Science and Technology in Mexico CONACyT (Scholarship Ref. No. 207858/2014). Partial support from DGAPA-UNAM (Grant No. 109913) was gratefully acknowledged. A. S. and M. P. gratefully acknowledge Fondazione Cariverona (Verona, Italy) for financial support in the framework of the “Verona Nanomedicine Initiative

Enhanced Second Harmonic Generation in Femtosecond Laser Inscribed Double-Cladding Waveguide of Nd:GdCOB Crystal

We report on the fabrication of double-cladding waveguides in Nd:GdCOB crystals by using femtosecond laser inscription with scanning speed of 0.5 mm/s. This prototype consists of two concentric tubular structures with nearly circular cross sections with different diameters. The fabricated cladding waveguides possess relatively low propagation losses of less than 0.65 dB/cm. The micro photoluminescence and second harmonic confocal images of the fabricated waveguides, which were performed by using a confocal microscope, have revealed that neither the fluorescence nor the nonlinear properties of the constituent crystals have been deteriorated during femtosecond lasermicromachining procedure. Under the pulsed laser pumping at fundamental wavelength of 1064 nm, the guided wave second harmonic generation (SHG) at 532 nm has been realized from the single and double cladding waveguides. Compared to the single-claddings (2.3 or 4.7%, depending on the diverse cladding diameters), the double cladding architecture has been found to be with enhanced SHG conversion efficiency (∼5.1%).The work was supported by the National Natural Science Foundation of China under Grants 11274203 and 11111130200, the Spanish Ministerio de Ciencia e Innovación (MICINN) through Consolider Program SAUUL CSD2007-00013 and Project FIS2009-09522, and the Centro de Láseres Pulsados (CLPU)