Nanomateriales para terapia e imagen en el infrarrojo

Tesis Doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Física de Materiales. Fecha de lectura: 20-01-201

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

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

Waveguiding microstructures in Nd:YAG with cladding and inner dual-line configuration produced by femtosecond laser inscription

We demonstrate a new design of waveguiding microstructure, which contains both cladding and inner dual-line configurations, in Nd:YAG laser crystals inscribed by femtosecond laser processing. Based on this prototype, a few “cladding + dual-line” hybrid structures with different parameters have been successfully manufactured in Nd:YAG. The waveguide lasing at 1.06 μm has been realized in the hybrid structures under 808-nm optical pump. Compared to the single dual-line waveguides, the dual-line core in hybrid configuration benefits from the large-area pump from the external cladding, reaching an enhancement of 26% on the maximum output power and of 24% on the slope efficiency of the waveguide lasing. In addition, the symmetric stress field of external cladding structure produces anisotropic stress field in the inner cores, supporting guidance along both TE and TM polarizations, thus differing significantly from the single dual-line waveguides.The work is supported by the Specialized Research Fund for the Doctoral Program of Higher Education of China (No.20130131130001) and Junta de Castilla y León under Project SA086A12-2. Support from the Centro de Láseres Pulsados (CLPU) is also acknowledged

Continuous-wave lasing at 1.06μm in femtosecond laser written Nd:KGW waveguides

We report on the buried channel waveguide laser at 1065 nm in Nd:KGW waveguides fabricated by femtosecond laser writing with dual-line approach. A relatively high scanning speed of 0.5 mm/s enables acceptable propagation loss less than 2 dB/cm. The fluorescence emission spectra of Nd3+ ions measured shows that the fluorescence properties were well preserved in the waveguide region. A stable continuous wave laser at 1065 nm has been obtained at room temperature in the buried channel waveguides by optical pumping at 808 nm. A maximum output power of 33 mW and a slope efficiency of 52.3% were achieved in the Nd:KGW waveguide laser system.The work is supported by the National Natural Science Foundation of China (No. 11274203), the Specialized Research Fund for the Doctoral Program of Higher Education of China (No. 20130131130001) and Junta de Castilla y León under project SA086A12-2. Support from the Centro de Láseres Pulsados (CLPU) is also acknowledged

Luminescence thermometry for brain activity monitoring: A perspective

Minimally invasive monitoring of brain activity is essential not only to gain understanding on the working principles of the brain, but also for the development of new diagnostic tools. In this perspective we describe how brain thermometry could be an alternative to conventional methods (e.g., magnetic resonance or nuclear medicine) for the acquisition of thermal images of the brain with enough spatial and temperature resolution to track brain activity in minimally perturbed animals. We focus on the latest advances in transcranial luminescence thermometry introducing a critical discussion on its advantages and shortcomings. We also anticipate the main challenges that the application of luminescent nanoparticles for brain thermometry will face in next years. With this work we aim to promote the development of near infrared luminescence for brain activity monitoring, which could also benefit other research areas dealing with the brain and its illnessesThis work was financed by the Spanish Ministerio de Innovación y Ciencias under project NANONERV PID 2019-106211RB-I00. BD acknowledges support from the Australian Research Council (DE200100985), RMIT University (Vice-Chancellor’s Fellowship Programme) and the Australian Academy of Sciences (JG Russell Award). PR-S is grateful for a Juan de la Cierva—Incorporación scholarship (IJC2019-041915-I). AB acknowledges funding from Comunidad de Madrid through TALENTO grant ref. 2019-T1/IND-14014. EX is grateful for a Juan de la Cierva - Incorporación scholarship (IJC2020-045229-I

The near-infrared autofluorescence fingerprint of the brain

This is the peer reviewed version of the following article: Lifante, J, del Rosal, B, Chaves-Coira, I, Fernández, N, Jaque, D, Ximendes, E. The near-infrared autofluorescence fingerprint of the brain. J. Biophotonics. 2020; 13:e202000154, which has been published in final form at https://doi.org/10.1002/jbio.202000154. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived VersionsThe brain is a vital organ involved in mostof the central nervous system disorders.Their diagnosis and treatment require fast,cost-effective, high-resolution and high-sensitivity imaging. The combinationof a new generation of luminescent nanoparticles and imaging systems work-ing in the second biological window (near-infrared II [NIR-II]) is emerging asa reliable alternative. For NIR-II imaging to become a robust technique at thepreclinical level, full knowledge of the NIR-II brain autofluorescence, responsi-ble for the loss of image resolution and contrast, is required. This work demon-strates that the brain shows a peculiar infrared autofluorescence spectrumthat can be correlated with specific molecular components. The existence ofparticular structures within the brain with well-defined NIR autofluorescencefingerprints is also evidenced, opening the door to in vivo anatomical imaging.Finally, we propose a rational selection of NIR luminescent probes suitable forlow-noise brain imaging based on their spectral overlap with brainautofluorescenceComunidad de Madrid, Grant/AwardNumber: B2017/BMD-3867RENIMCM;European Cooperation in Science andTechnology, Grant/Award Number:CA17140; Fundación para la Investigación Biomédica del Hospital Universitario Ramón y Cajal, Grant/Award Number:IMP18_38(2018/0265); Horizon 2020 Framework Programme, Grant/AwardNumber: 801305; Instituto de Salud CarlosIII, Grant/Award Number: PI16/00812;Ministerio de Ciencia, Innovación y Universidades, Grant/Award Number:FJC2018-036734-I; Ministerio deEconomía y Competitividad, Grant/AwardNumbers: MAT2016-75362-C3-1-R,MAT2017-83111R, MAT2017-85617-

Monolithic crystalline cladding microstructures for efficient light guiding and beam manipulation in passive and active regimes

Miniature laser sources with on-demand beam features are desirable devices for a broad range of photonic applications. Lasing based on direct-pump of miniaturized waveguiding active structures offers a low-cost but intriguing solution for compact light-emitting devices. In this work, we demonstrate a novel family of three dimensional (3D) photonic microstructures monolithically integrated in a Nd:YAG laser crystal wafer. They are produced by the femtosecond laser writing, capable of simultaneous light waveguiding and beam manipulation. In these guiding systems, tailoring of laser modes by both passive/active beam splitting and ring-shaped transformation are achieved by an appropriate design of refractive index patterns. Integration of graphene thin-layer as saturable absorber in the 3D laser structures allows for efficient passive Q-switching of tailored laser radiations which may enable miniature waveguiding lasers for broader applications. Our results pave a way to construct complex integrated passive and active laser circuits in dielectric crystals by using femtosecond laser written monolithic photonic chipsThis work was supported by National Natural Science Foundation of China (No. 11274203), Specialized Research Fund for the Doctoral Program of Higher Education of China (No. 20130131130001), and Junta de Castillay León under project SA086A12-

Optical spectroscopy of Yb3+ centers in BaMgF4 ferroelectric crystal

The following article appeared in Journal of Applied Physics 110.6 (2011): 063102 and may be found at http://scitation.aip.org/content/aip/journal/jap/110/6/10.1063/1.3638040We report on the optical characterization of Yb3+ doped BaMgF4+ nonlinear fluoride crystal grown by the Czochralski technique. Low temperature absorption spectroscopy reveals that Yb3+ incorporates into the matrix at four well differentiated centers. High resolution site selective experiments have been performed to determine the energy level schemes associated with the major Yb3+ centers detected in the system. The fluorescence decay times recorded at 10 K under selective excitation are analyzed for each Yb3+ center. The spectroscopic behavior of the codoped Yb3+:Na+:BaMgF4+ system has been also investigated. Codoping with Na+ eliminates two Yb3+ centers present in the singly doped Yb3+:BaMgF 4+ crystal. The charge compensation mechanisms and site location for Yb3+ in the fluoride matrix are discussedThis work has been supported by Spanish MICINN under Contract Nos. MAT2010-17443 and MAT2009-06580, Comunidad de Madrid under Grant No. PHAMA S2009/MAT-1756 and Universidad Autónoma de Madrid under Contract No. CCG10-UAM/MAT-5290

Torque Teno Virus in Nasopharyngeal Aspirate of Children With Viral Respiratory Infections

Background: Torque teno virus (TTV) is a ubiquitous anellovirus responsible for persistent infections and is considered a marker of immune function. The role of TTV as a facilitator of respiratory infections (RIs) is unknown. Objectives: Our aim was to estimate, in a prospective study, the prevalence of TTV in the nasopharyngeal aspirate (NPA) of hospitalized children <5 years old, with RIs and correlate them with outcomes and immune response. Patients and methods: NPA was taken for testing of 16 respiratory viruses by reverse transcription-polymerase chain reaction (PCR), TTV PCR, and immunologic study. Results: Sixty hospitalized children with an RI were included. A total of 51/60 patients had positive common respiratory viral (CRV) identification. A total of 23/60 (38.3%) children were TTV+ in NPA. TTV+ patients had other CRVs in 100% of cases versus 78.3% in TTV- ( P = 0.029). The TTV+ patients tended to be older, have fever, and to need pediatric intensive care unit admission more often than TTV- patients. Abnormal chest radiograph was more frequent in the TTV+ patients, odds ratios 2.6 (95% CI: 1.3-5.2). The genetic expression of filaggrin (involved in epithelial barrier integrity) was lower in TTV+ patients; however, the levels of filaggrin in the NPA were increased. Conclusions: TTV infection is common in children with RI and could be associated with abnormal imaging in radiograph, greater severity and an alteration in filaggrin gene expression and protein release.Funded by projects PI18CIII/0009, PI18/00177, and PI21/00377, funded by Instituto de Salud Carlos III (ISCIII) and co-funded by the European Union. There are no conflicts of interest.S