In this report we studied the properties of the dye IR806 and possible mechanisms of the dye sensitization effect on ytterbium-erbium co-doped upconversion nanoparticles. We found that the dye IR806 has two primary emission peaks in the NIR spectral range at around 850 nm and at around 950 nm. The intensity of these peaks were observed to be affected by the concentration of the dye and the addition of Gadolinium(III) chloride and Yttrium(III) chloride. Specifically increases in the intensity of the 950 nm peak relative to the 850 nm were of interest since ytterbium readily absorbs 950 nm and transfers this energy in the upconversion process. Our hypothesis is that the change in the intensity of the 850 nm and the 950 nm peak is associated with aggregation of the dye IR806 and the amount of monomers and dimers. Results from adding ytterbium-erbium co-doped upconversion nanoparticles in IR806-ethanol solution points to the picture of dimers being formed on the surface on the nanoparticles. This analysis is however based on the assumption that the 850 nm emission peak of IR806 is associated with monomers and that the 950 peak is associated with dimers, which is yet to be confirmed and further studies are therefore needed.

The subject of this these is a preparation and printing of upconversion marks that have been printed by two printing techniques, namely screen printing and pad printing. The makrs were designed to visualize another chemical code identifiable by instrumentation. The impact of chemical code components on the fluorescence intensity of upconversion marks and the impact of individual components on printability and print sustainability were studied. The upconversion pigment was excited by NIR laser.

The synthesis and surface modification of upconverting nanoparticles (UCNPs) composed of a host lattice NaYF4 doped with sensitizers (Yb3+, Nd3+) and luminescent emitters (Er3+) were investigated for potential integration in biological applications.The fascination of NaYF4: Nd3+, Yb3+, Er3+ upconverting nanoparticles derives from their capacity to be excited in the biologically transparent window (650-950 nm) enabling deep tissue penetration. In particular, the ability to convert near infrared radiation into visible light (upconversion), which prevents autofluorescence and over-heating effect of biological tissues.In biological applications especially in vivo, morphology and size of the nanoparticles plays a crucial role in determination of cellular responses and fate in living organism. Heterogeneously sized nanoparticles, in contrast to uniform ones, might be distributed unevenly in the organism causing undesirable toxic side effects. Therefore, precise control of the nanoparticle size, distribution, and reproducibility were main tasks in the first part of this work. Colloidal upconverting nanoparticles were synthesized using coprecipitation method. Synthetic parameters such as reaction temperature (280-320 °C), and time (5-30 min) were used to tailor the nanoparticle morphology, crystal phase (cubic or hexagonal) and particle size (sub-10 - 20 nm). Integration of these nanoparticles in biological applications requires dispersibility in aqueous media. Hence hydrophobic UCNPs were surface-modified with low molecular weight ligands including O-phospho-L-threonine, alendronic acid, and PEG-phosphate ligands to generate water-dispersible UCNPs. Furthermore, in this work, photocrosslinking of diacetylenes is presented as an effective way to create robust UCNPs with a crosslinked shell. Finally, the protein corona formation on UCNPs coated with charged, zwitterionic and nearly neutral ligands was investigated. The composition of protein binding to UCNP is notably influenced by the surface charges of the UCNPs. Overall, the results obtained in the frame of this work show that the NaYF4: Nd3+, Yb3+, Er3+ UCNPS have the potential to replace conventional fluorophores in bioimaging applications due to their remarkable optical properties, as well as the derivatization flexibility of their surface

Lumineszenzmessungen und Lumineszenz-Bildgebung spielen in den Biowissenschaften eine wichtige Rolle und ermöglichen den Nachweis und die Detektion von biomolekularen Wechselwirkungen und Analyten, die selbst keine intrinsische Farbe und / oder Lumineszenz aufweisen. Ein vielversprechender Ansatz ist die Verwendung von im Nahinfrarot (NIR) anregbaren, mehrfarbig emittierenden Aufkonversions-Nanokristallen (UCNPs) wie mit Yb3+ und Er3+ dotierten NaYF4-Nanopartikeln. Diese Nanopartikel können als Lumineszenzreporter oder Energiedonoren (Nanolampen) für die Anregung von Analyt-sensitiven Sonden benutzt werden. In dieser Arbeit, die den Aufbau eines selbstreferenzierten UCNP-basierten Sensors für die Ermittlung von pH-Werten als Ziel hatte, wurden beide Sensorkomponenten gezielt ausgewählt, synthetisiert und spektroskopisch charakterisiert. Dies beinhaltete i) UCNPs mit unterschiedlichen Größen, Partikelarchitekturen und Oberflächenfunktionalisierungen oder -beschichtungen und ii) Rosamin-Farbstoffe mit Absorptions- und Emissionseigenschaften, die für die gewünschte Kombination mit UCNPs geeignet sind. Des Weiteren wurde eine umfassende Untersuchung der chemischen Stabilität von unterschiedlich oberflächenfunktionalisierten und beschichteten UCNPs in biologisch relevanten Puffern durchgeführt. Für die schnelle Ermittlung der UCNP-Stabilität wurde eine einfache optische Überwachungsmethode zum Nachweis der Partikeldisintegationentwickelt, die die Abhängigkeit der UC-Lumineszenz und ihrer Lebensdauer von der Partikelgröße und Oberfläche ausnutzt. Im letzten Teil der Doktorarbeit wurden pH-Sensorfilme und Nanosensoren durch die Kombination der optimierten Yb3+, Er3+-co-dotierten UCNPs mit den pH-sensitiven Rosaminfarbstoffen als Energie-Akzeptoren unter Verwendung eines einfachen inneren Filters (Reabsorption) oder eines RET – Sensorkonzept konstruiert. / Luminescence sensing and imaging play an important role in the life sciences, enabling the detection and monitoring of biomolecular interactions and molecular targets that have no intrinsic colour and/or luminescence even in complex biological samples. A very promising approach presents the utilization of near-infrared (NIR) excitable multi-colour emissive upconversion nanocrystals (UCNPs) like NaYF4 nanoparticles doped with Yb3+ and Er3+ as luminescent reporters and as energy donors or “nanolamps” for the excitation of analyte-responsive probes. In this work, aiming at the design of self-referenced UCNP-based sensors for pH, both sensor components were rationally designed, synthesized, and spectroscopically characterized. This included i) UCNPs with different sizes, architectures, and surface chemistries or coatings and ii) rosamine dyes with absorption and emission properties adapted to the UC emission of the NaYF4: Yb3+, Er3+-doped UCNPs. Additionally, an extensive study of the chemical stability of differently surface functionalized and coated UCNPs in biologically relevant buffers was performed. To simplify stability monitoring, an optical monitoring method was developed for the detection of particle disintegration utilizing the size and environment dependence of the UC emission intensity and decay kinetics. Finally, pH sensor films and nanosensors were constructed by combining the initially optimized Yb3+, Er3+ co-doped UCNPs with pH-responsive rosamine dyes acting as energy acceptors utilizing a simple inner filter (reabsorption)- and a RET-based sensor concept.

This diploma thesis deals with evaluation of toxicity and bioaccumulation of photon-upconversion nanoparticles (UCNPs) in model plant maize (Zea mays). Lanthanide-doped UCNPs with different composition and size were tested in three different concentrations in this work. The exposure took place for 168 hours. Toxicity was assessed based on four macroscopic toxicological endpoints (mortality, the length of belowground part of the plants, the length of aboveground part of the plants and whole plants length). Spatial distribution of elements yttrium, ytterbium, erbium and gadolinium in model plants was determined using laser induced breakdown spectroscopy with spatial resolution of 100 m and 26 m. Distribution of UCNPs in plants was further studied with photon-upconversion microscanning with spatial resolution of 40 m. Stability of UCNPs during and after the plant exposure was also discussed in this thesis.

Lanthanide-based nanoparticles are of interest for optical displays, catalysis, telecommunication, bio-imaging, magnetic resonance imaging, multimodal imaging, etc. These applications are possible partly because the preparation of lanthanide-based nanoparticles has made tremendous progress. Now, nanoparticles are routinely being made with a good control over size, crystal phase and even shape. Despite the achievements, little attention is given to the fundamental physical chemistry aspects, such as crystal structure, architecture, cation exchange, etc. The results of the study on the crystal structures of LnF3 nanoparticles show that the middle GdF3 and EuF3 nanoparticles have two crystal phases, which has then been tuned by doping with La3+ ions. However, the required doping level is very different from the bulk. While the results for the bulk are well explained by thermodynamic calculations, kinetics is actually responsible for the results of the undoped and doped GdF3 and EuF3 nanoparticles. The attempt to make LnF3 core-shell nanoparticles led to the finding of cation exchange, a phenomenon that upon exposure of LnF3 nanoparticles to an aqueous solution containing Ln3+ ions, the Ln3+ ions in the nanoparticles are replaced by the Ln3+ ions in the solution. The consequence of the cation exchange is that LnF3 core-shell nanoparticles are unlikely to form in aqueous media using a core-shell synthesis procedure. It has also been verified that nanoparticles synthesized using an alloy procedure do not always have an alloy structure. This means that the core-shell and alloy structure of nanoparticles in the literature may not be true. The investigation of the architecture of nanoparticles synthesized in aqueous media is extended to those synthesized in organic media. The dopant ion distribution in NaGdF4 nanoparticles has been examined. It has been found that they don’t have the generally assumed statistical dopant distribution. Instead, they have a gradient structure with one type of Ln3+ ions more concentrated towards the center and the other type more concentrated towards the surface of the nanoparticles. With the understanding of these physical insights, lanthanide-based core-shell nanoparticles are prepared using the cation exchange. These core-shell nanoparticles containing a photoluminscent core and a paramagnetic shell are promising candidates for multimodal imaging. / Graduate

[ES] El cáncer es una de las principales causas de muerte a nivel mundial. Los tratamientos anticancerígenos generalmente usados tienen diversos efectos secundarios producidos por su baja especificidad. Esta es una de las razones por las que se sigue en continua búsqueda de nuevos tratamientos. Dentro de estas nuevas investigaciones se encuentra el extenso campo de la nanomedicina, es decir, el estudio de nuevos materiales a escala nanométrica. Esta permite reducir dichos efectos secundarios aumentando la selectividad y especificidad de los tratamientos. Dentro de los nanomateriales se encuentran las nanopartículas de upconversion que son capaces de absorber luz en el infrarrojo cercano y emitirla en la región ultravioleta-visible. Por otro lado, desde el principio de la historia de la medicina la luz se ha empleado como forma de tratamiento teniendo un rol muy importante. Un inconveniente para dichos tratamientos suele ser la necesidad de emplear luz de la región ultravioleta-visible, pues las biomoléculas son capaces de absorber y produce daño celular. En este contexto, la presente Tesis Doctoral se centra en el estudio de nuevas formas de tratamiento anticancerígeno combinando nanomedicina y luz. Para ello se han desarrollado nuevos fármacos fototóxicos y nuevos materiales capaces de ser activados mediante luz infrarroja cercana. En primer lugar, se sintetizaron nuevas fluoroquinolonas para explorar sus propiedades fototóxicas para su uso en fotoquimioterapia (Capítulo 3 de la Tesis). Se estudiaron las características fotofísicas y fotoquímicas de los nuevos compuestos, además de su capacidad para producir mayor fototoxicidad en las células en comparación con las fluoroquinolonas como la lomefloxacina mediante la aplicación de luz ultravioleta. En base a los resultados obtenidos se realizó un estudio para determinar las diferencias entre las interacciones de algunas fluoroquinolonas dihalogenadas, incluidas las comentadas anteriormente, y biomoléculas como ADN y proteínas. La reactividad de sus intermedios fotogenerados también se estudió en el Capítulo 4. Tras conocer en profundidad la capacidad fototóxica de los nuevos fármacos, en el Capítulo 5 se llevó a cabo el diseño de un nanosistema compuesto por fluoroquinolonas y nanopartículas de conversión ascendente. Se demostró la alta capacidad fototóxica de este nuevo nanosistema. De esta manera, se generó actividad fototóxica a partir de una fluoroquinolona sin el uso de luz ultravioleta Por otro lado, la formación de profármacos abre la puerta a la administración selectiva de fármacos contra el cáncer. Los profármacos consisten en la unión fotolábil de una molécula capaz de ser activada por la luz y el fármaco de interés. Sin embargo, un conocimiento profundo de las propiedades fotofísicas y fotoquímicas del fotodisparador y de los potenciales redox de ambos miembros de la diada puede ser crucial para obtener la fotoliberación deseada. Así, en el Capítulo 6, se destacó la relevancia de estos datos utilizando un profármaco formado por un derivado de cumarina como molécula fotoactivable y colchicina como fármaco. Finalmente, en el Capítulo 7 se exploró la síntesis de un nuevo nanosistema que contiene un profármaco formado por un derivado de cumarina unido al fármaco contra el cáncer clorambucilo y nanopartículas biocomatibles de conversión ascendente. La adición de albúmina de suero humano como recubrimiento de las nanopartículas cumple la doble función de obtener nanopartículas biocompatibles y ser el lugar de carga del profármaco. / [CA] El càncer és una de les principals causes de mort a nivell mundial. Els tractaments anticancerígens generalment usats tenen diversos efectes secundaris produïts per la seva baixa especificitat. Aquesta és una de les raons per les que se segueix en contínua recerca de nous tractaments. Dins d'aquestes noves investigacions es troba l'extens camp de la nanomedicina, és a dir, l'estudi de nous materials a escala nanomètrica. Aquesta permet reduir aquests efectes secundaris augmentant la selectivitat i especificitat dels tractaments. Dins dels nanomaterials es troben les nanopartícules de upconversion que són capaços d'absorbir llum en l'infraroig proper i emetre-la en la regió ultraviolada-visible. D'altra banda, des del principi de la història de la medicina la llum s'ha emprat com a forma de tractament tenint un paper molt important. Un inconvenient per aquests tractaments sol ser la necessitat d'emprar llum de la regió ultraviolada-visible, ja que les biomolècules són capaços d'absorbir-la i produïr dany cel·lular. En aquest context, la present Tesi Doctoral es centra en l'estudi de noves formes de tractament anticancerigen combinant nanomedicina i llum. Per això s'han desenvolupat nous fàrmacs fototòxics i nous materials capaços de ser activats mitjançant llum infraroja propera. En primer lloc, es van sintetitzar noves fluoroquinolones per explorar les seves propietats fototòxiques per al seu ús en fotoquimioteràpia (Capítol 3 de la Tesi). Es van estudiar les característiques fotofísiques i fotoquímiques dels nous compostos, a més de la seva capacitat per produir major fototoxicitat en les cèl·lules en comparació amb les fluoroquinolones com la lomefloxacina mitjançant l'aplicació de llum ultraviolada. En base als resultats obtinguts es va realitzar un estudi per determinar les diferències entre les interaccions d'algunes fluoroquinolones dihalogenades, incloses les comentades anteriorment, i biomolècules com ADN i proteïnes. La reactivitat de les seves intermedis fotogenerats també es va estudiar en el Capítol 4. Després de conèixer en profunditat la capacitat fototòxica dels nous fàrmacs, en el Capítol 5 es va dur a terme el disseny d'un nanosistema compost per fluoroquinolones i nanopartícules de upconversion. Es va demostrar l'alta capacitat fototòxica d'aquest nou nanosistema. D'aquesta manera, es va generar activitat fototòxica a partir d'una fluoroquinolona sense l'ús de llum ultraviolada D'altra banda, la formació de profàrmacs obre la porta a l'administració selectiva de fàrmacs contra el càncer. Els profàrmacs consisteixen en la unió fotolábil d'una molècula capaç de ser activada per la llum i el fàrmac d'interès. No obstant això, un coneixement profund de les propietats fotofísiques i fotoquímiques del fotodisparador i dels potencials redox de tots dos membres de la diada pot ser crucial per obtenir el fotoalliberament desitjada. Així, en el Capítol 6, es va destacar la rellevància d'aquestes dades utilitzant un profàrmac format per un derivat de cumarina com a molècula fotoactivable i colquicina com a fàrmac. Finalment, en el Capítol 7 es va explorar la síntesi d'un nou nanosistema que conté un profàrmac format per un derivat de cumarina unit a l'fàrmac contra el càncer clorambucilo i nanopartícules biocomatibles de upconversion. L'addició d'albúmina de sèrum humà com a recobriment de les nanopartícules compleix la doble funció d'obtenir nanopartícules biocompatibles i ser el lloc de càrrega del profàrmac. / [EN] Cancer is one of the leading causes of death worldwide. Generally used anticancer treatments have various side effects produced by their low specificity. This is one of the reasons why the search for new treatments continues. Within these new investigations is the extensive field of nanomedicine, which can be explained as the study of new materials on a nanometric scale. It can be translated in the reduction of these side effects by increasing the selectivity and specificity of the treatments. Among the nanomaterials are upconversion nanoparticles that are capable of absorbing light in the near infrared and emit it in the ultraviolet-visible region. On the other hand, since the beginning of the history of medicine, light has been used as a form of treatment, having a very important role. A drawback for such treatments is sometimes the need to use light from the ultraviolet-visible region since biomolecules are capable of absorbing and causing cell damage. In this context, this Doctoral Thesis focuses on the study of new forms of anticancer treatment combining nanomedicine and light. For this, new phototoxic drugs and new materials capable of being activated by near infrared light have been developed. First, new fluoroquinolones were synthesized to explore their phototoxic properties for using in photochemotherapy (Chapter 3 of the Thesis). The photophysical and photochemical characteristics of the new compounds were studied, in addition to their ability to produce greater phototoxicity in cells than fluoroquinolones such as lomefloxacin by applying ultraviolet light. Based on the results obtained, a study was carried out to determine the differences between the interactions of some dihalogenated fluoroquinolones including the above commented, and biomolecules such as DNA and proteins. The reactivity of their photo-generated intermediates was also studied in Chapter 4. After a deep knowledge of the phototoxic capacity of the new drugs, design of a nanosystem composed of fluoroquinolones and upconversion nanoparticles was carried out in Chapter 5. The high phototoxic capacity of this new nanosystem was demonstrated. In this way phototoxic activity was generated from a fluoroquinolone without the use of ultraviolet light. On the other hand, the formation of prodrugs opens a door to the selective administration of anticancer drugs. Prodrugs consist of the photolabile binding of a molecule capable of being activated by light and the drug of interest. However, a knowledge of the photophysical and photochemical properties of the phototrigger as well as the redox potentials of both members of the dyad can be crucial to obtain the desired photorelease. Thus, in Chapter 6, the relevance of these data was highlighted using a prodrug formed by a coumarin derivative as a photoactivatable molecule and colchicine as a drug. Finally, in Chapter 7 the synthesis of a new nanosystem containing a prodrug formed by a derivative of coumarin linked to the anticancer drug chlorambucil, and upconversion biocompatible nanoparticles was explored. The addition of human serum albumin as a coating for the nanoparticles fulfills the dual function of obtaining biocompatible nanoparticles and being the loading site for the prodrug. / Anaya González, C. (2021). Design of New Up-conversion Systems for Anticancer Therapies [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/172665 / TESIS

The present work broaches the physics of light-matter interaction, chiefly using nonlinear optical spectroscopy in a newly developed framework termed as Photon Management Concept. This way, existing fragments dealing with specific properties of harmonic and upconversion nanoparticles (HNPs/UCNPs) are consolidated into a full and coherent picture with the primary goal of understanding the underlying physical processes and their impact on the application side, especially in terms of imaging techniques, via suitable experimental and numerical studies. Contemporary optical setups involving contrast-enhancing agents are frequently limited in their excitation and detection configurations owing to a specialization to a select number of markers. As a result, the bandwidth of experimental methods and specimens that may be investigated is severely restricted in a large number of state-of-the-art setups. Here, an alternative approach involving HNPs and UCNPs, respectively, is presented providing an overview from their synthesis to optical characterization and to potential fields of application. Based on their inherent flexibility based on their nonlinear optical response, especially in terms of wavelength and intensity tunability, the PMC alleviates prevalent limitations by dynamically adapting the setup to a sample instead of the preliminary culling to a reduced number of eligible specimens that must not change their optical properties significantly during investigation. The use of HNPs supersedes such concerns due to their nearly instantaneously generated, strongly anti-Stokes shifted, coherent emission capable of producing radiation throughout the visible spectral range, including infrared and ultraviolet wavelengths. This way, HNPs transcend the traditional field of imaging and introduces potential applications in optomanipulation or holographic techniques. Thorough (nonlinear) optical characterization of UCNPs and alkali niobate HNP ensembles is performed to assess the fundamental physical mechanisms interwoven with numerical studies leading to their wide-ranging applicability. Final remarks show that HNPs are ideal candidates for realization of the PMC and yet hold an even further potential beyond current prospects.