http://hdl.handle.net/10366/133043 Sun, 23 Aug 2026 07:03:40 GMT 2026-08-23T07:03:40Z http://hdl.handle.net/10366/172253 [ES] La leucemia linfoblástica aguda de células B precursoras (LLA-B) se produce como consecuencia de una acumulación de células pre-B y células pro-B en la médula ósea, debido a un bloqueo en el proceso de diferenciación hacia la célula B madura. La LLA-B representa aproximadamente el 85% de los casos de LLA infantiles. Aunque las terapias actuales permiten alcanzar tasas de curación cercanas al 90%, la LLA-B continúa siendo una de las principales causas de mortalidad pediátrica debido a la elevada tasa de recaídas y a los efectos secundarios a largo plazo. Se estima que al menos un 5% de los recién nacidos presentan algunas de estas alteraciones genéticas, aunque solo un 1% de ellos acaban padeciendo la enfermedad. Esto indican que la presencia de una alteración genética primaria no constituye el único factor determinante en la génesis de la LLA-B; por el contrario, se considera que la progresión hacia la enfermedad requiere un segundo evento, inducido por un estrés inmunológico asociados a factores ambientales, que favorece la adquisición de mutaciones o alteraciones genéticas secundarias, como sería el caso de la exposición a infecciones. En estos casos, los modelos de ratones heterocigotos para el gen Pax5 (Pax5+/-) expuestos a patógenos comunes median el desarrollo de LLA-B por mecanismos de la inmunidad innata, que provocan inflamación y el consecuente daño en el ADN. Sin embargo, estas señales inflamatorias no incrementan el riesgo de desarrollo de LLA-B en ratones que no presentan ningún tipo de alteración en el gen Pax5. Por lo que, usamos modelos de ratón con el fin de dilucidar el papel de Pax5 en la respuesta al daño en el ADN. No obstante, existen algunos casos en los que se produce el desarrollo de la LLA-B en ausencia de estrés inmunológico, como en las LLA-B que presentan deleciones en el brazo corto del cromosoma 9 (9p). En tales situaciones, la pérdida de PAX5 se asocia con el desarrollo de la leucemia sin necesidad de exposición a factores ambientales. Con el fin de comprender como se desarrollan estas LLA-B usamos modelos de ratones heterocigotos para genes en genes presentes en esta región 9p. Thu, 01 Jan 2026 00:00:00 GMT http://hdl.handle.net/10366/172253 2026-01-01T00:00:00Z http://hdl.handle.net/10366/172251 [ES] La involución postlactancia constituye un proceso fisiológico de regresión mamaria caracterizado por muerte epitelial masiva, remodelación de la matriz extracelular y restablecimiento del estroma adiposo. Aunque tradicionalmente se ha considerado un periodo transitoriamente protumorogénico, evidencias emergentes indican que la eficiencia de su resolución determina la susceptibilidad posterior al cáncer de mama. Esta tesis parte de la hipótesis de que la potenciación farmacológica de la involución puede transformar esta ventana biológica en una oportunidad de quimioprevención primaria. Para ello, se desarrolló un modelo tridimensional de organoides mamarios murinos capaz de reproducir la diferenciación lactogénica y la involución postlactancia. Mediante este sistema se demostró que la activación de STAT3 y la inhibición de AKT1 aceleran la involución in vitro, promoviendo apoptosis, biogénesis lisosomal y programas transcripcionales de remodelación tisular. Ambos tratamientos convergieron en la activación sostenida del eje STAT3–lisosomal, núcleo molecular de la regresión epitelial. La validación in vivo en un modelo murino de alto riesgo, deficiente en Brca1/P53, confirmó que la administración de los moduladores de estas proteínas en el momento del destete acelera la involución, favoreciendo una eliminación epitelial más eficiente y una resolución tisular más rápida. Los análisis transcriptómicos y proteómicos revelaron una supresión coordinada de programas proliferativos y biosintéticos, una reorganización estructural de la matriz extracelular y rasgos compatibles con una estabilización mioepitelial, todo ello coherente con un microambiente menos permisivo para la iniciación tumoral. Funcionalmente, ambas intervenciones incrementaron significativamente la latencia tumoral y redujeron la incidencia de cáncer de mama, sin modificar la progresión de los tumores ya establecidos, lo que indica un efecto predominante sobre la fase de iniciación. A largo plazo, las glándulas tratadas mostraron una menor área ductal, una reducción de la proliferación epitelial y una contracción del campo de cancerización, definida por una reducción del compartimento epitelial susceptible a la transformación. Estos resultados demuestran que la potenciación farmacológica de la involución postlactancia reprograma de manera duradera el tejido mamario hacia un estado más estable e hipoproliferativo, disminuyendo su vulnerabilidad oncogénica. De este modo, la involución postlactancia se consolida como una ventana de intervención preventiva y STAT3 y AKT1 emergen como dianas estratégicas para el desarrollo de nuevas estrategias de quimioprevención primaria frente al cáncer de mama. Thu, 01 Jan 2026 00:00:00 GMT http://hdl.handle.net/10366/172251 2026-01-01T00:00:00Z http://hdl.handle.net/10366/171913 [ES] La serotonina (5-HT) es una neurohormona que regula el tono vascular por mecanismos directos e indirectos, a través del sistema nervioso autónomo y sensorial, mediante una amplia familia de receptores serotonérgicos. Los mecanismos serotonérgicos implicados en la modulación de la neurotransmisión simpática y sensorial CGRPérgica en la vasculatura sistémica han sido caracterizados por nuestro grupo y otros autores en ratas macho. Sin embargo, el sexo biológico influye tanto en el metabolismo de la 5-HT y la expresión de sus receptores, como en la neurotransmisión simpática y sensorial CGRPérgica, lo que limita la comprensión y el desarrollo de dianas farmacológicas eficaces para el sexo femenino en patologías cardiovasculares y neurovasculares. La presente Tesis Doctoral tiene como objetivo determinar si los mecanismos serotonérgicos involucrados en la regulación cardiovascular presentan diferencias dependientes del sexo biológico en ratas. Para ello, en ratas hembra pithed, se ha estudiado el papel diferencial de los distintos receptores de 5-HT sobre las respuestas vasculares obtenidas por liberación endógena de noradrenalina y del péptido relacionado con el gen de la calcitonina (CGRP), así como la posible implicación de mediadores dependientes de endotelio en la respuesta noradrenérgica. Los resultados obtenidos muestran que el sexo biológico influye en el tono vascular basal y en los mecanismos serotonérgicos que regulan tanto la neurotransmisión simpática vascular como la inervación sensorial CGRPérgica perivascular, modificando el tipo y subtipo de receptores de 5-HT implicados, su localización en la unión neuroefectora, y las vías indirectas involucradas. Estos hallazgos podrían abrir nuevas estrategias terapéuticas dependientes del sexo en el tratamiento de enfermedades cardiovasculares y neurovasculares.; [EN] Serotonin (5-HT) is a neurohormone that regulates vascular tone by direct and indirect mechanisms via the autonomic and sensory nervous systems, acting through a large family of serotonergic receptors. The serotonergic mechanisms involved in the modulation of sympathetic and sensory CGRPergic neurotransmission in the systemic vasculature have been characterised by our group and others in male rats. However, biological sex influences 5-HT metabolism and receptor expression, as well as sympathetic and sensory CGRPergic neurotransmission, which limits the understanding and development of effective pharmacological targets for the female sex in cardiovascular and neurovascular disorders. The aim of the present Doctoral Thesis was to determine whether the serotonergic mechanisms involved in cardiovascular regulation display sex-dependent differences in rats. To do so, female pithed rats were used to study the role of different 5-HT receptors on vascular responses elicited by the endogenous release of noradrenaline and calcitonin generelated peptide (CGRP), along with the possible involvement of endothelium-dependent mediators in the noradrenergic response. The results show that biological sex influences basal vascular tone and the serotonergic mechanisms regulating both vascular sympathetic neurotransmission and perivascular sensory CGRPergic outflow, modifying the 5-HT receptor types and subtypes involved, their localisation at the neuroeffector junction, and the indirect pathways implicated. Altogether, these findings may contribute to the development of novel sex-dependent therapeutic strategies for cardiovascular and neurovascular diseases. Thu, 01 Jan 2026 00:00:00 GMT http://hdl.handle.net/10366/171913 2026-01-01T00:00:00Z http://hdl.handle.net/10366/171252 [EN]Chronic myeloid leukemia (CML) is a myeloproliferative neoplasm driven by the BCR::ABL1 fusion oncogene, a constitutively active tyrosine kinase that transforms hematopoietic stem cells (HSCs) and generates leukemic stem cells, which sustain disease progression and treatment resistance. C3G, a regulator of the Rap1 GTPase, interacts with BCR::ABL1 and participates in processes such as cell signaling, adhesion, and differentiation. In addition, C3G plays an active role in hematopoiesis, regulating HSC fate and hematopoietic differentiation. Although its role in CML was previously unclear, this study demonstrates that its regulation is critical. In a murine model of CML, early deletion of C3G attenuates disease development: it delays onset, reduces circulating neutrophils, decreases leukemic infiltration, and prolongs survival (particularly in females). These effects are associated with alterations in myeloid progenitors—specifically, an accumulation of granulocyte-committed progenitors—and with impaired neutrophil migration and functional capacity. At the cellular level, both overexpression and inhibition of C3G in BCR::ABL1 positive cells do not affect proliferation but do increase sensitivity to imatinib. This enhanced response correlates with reduced activation of the JAK/STAT pathway (JAK2, STAT3, STAT5), while other pathways such as ERK or AKT remain largely unchanged. Moreover, low C3G levels impair STAT3-dependent neutrophil differentiation under non-oncogenic conditions. Overall, C3G functions as a fine-tuned modulator of leukemogenic signaling, with intermediate levels required for optimal pathway activity. Its dysregulation limits CML progression and enhances treatment response, positioning C3G as a potential therapeutic target to improve the efficacy of tyrosine kinase inhibitors. Thu, 01 Jan 2026 00:00:00 GMT http://hdl.handle.net/10366/171252 2026-01-01T00:00:00Z http://hdl.handle.net/10366/170354 [ES] Las RASopatías asociadas a alteraciones en los genes NF1 y SPRED1 presentan una marcada heterogeneidad clínica y molecular, donde el principal obstáculo tras el diagnóstico genético es la interpretación funcional de las variantes identificadas. Con el objetivo de superar este desafío, la presente tesis doctoral ha creado un flujo de trabajo experimental multidisciplinar que combina el análisis de variantes en NF1 y SPRED1 reportadas en bases de datos públicas y de pacientes de la DIERCyL, el modelado estructural y de estabilidad proteica in silico, la señalización celular, proliferación, y morfometría en las líneas celulares HEK293T y NIH3T3. Los análisis de las bases de datos genéticas identificaron hotspots estructurales críticos en la proteína neurofibromina (CSRD, GRD y Armadillo1), mientras que las variantes en SPRED1 mostraron una distribución homogénea, sugiriendo mecanismos patogénicos distintos. En el caso de las variantes en NF1 y SPRED1 de los pacientes, el análisis energético reveló un espectro continuo en neurofibromina que va desde haploinsuficiencia hasta dominancia negativa en truncantes tardías, mientras que en SPRED1 predominó la pérdida de función. Los ensayos celulares in vitro, mostraron dinámicas de señalización celular diferentes según el tipo de variante analizada en los genes NF1 y SPRED1. En particular, la hiperactivación de ERK emergió como el evento molecular más determinante para la patogenicidad de las variantes. La coactivación de p38 identificó variantes de mayor severidad clínica, mientras que la relación inversa p- ERK/p-AKT(Ser473) reveló un circuito de retroalimentación negativa entre las rutas de señalización MAPK y PI3K/AKT. Los ensayos de proliferación celular y el análisis cuantitativo del tamaño celular revelaron fenotipos consistentes con el grado de desregulación de MAPK, proporcionando biomarcadores fenotípicos adicionales para diferenciar entre variantes patogénicas y benignas en ambos genes. La relevancia tisular de HEK293T (contextos epiteliales/neuroectodérmicos) y NIH3T3 (mesenquimales) permitió reproducir la heterogeneidad clínica observada en pacientes. Los resultados de esta tesis doctoral han permitido reclasificar variantes de significado incierto en ambos genes e identificar la hiperactivación de ERK como diana terapéutica prioritaria, apoyando el uso de inhibidores de MEK en contextos compatibles con esta desregulación. En conjunto, este trabajo establece un marco integral para la interpretación funcional de variantes en RASopatías y para el desarrollo de futuras estrategias de medicina personalizada.; [EN] RASopathies associated with alterations in the NF1 and SPRED1 genes exhibit marked clinical and molecular heterogeneity, where the main challenge after genetic diagnosis lies in the functional interpretation of the identified variants. To address this issue, this doctoral thesis established a multidisciplinary experimental workflow that integrates the analysis of NF1 and SPRED1 variants reported in public databases and in patients from the DIERCyL cohort, together with in silico structural and protein-stability modeling, cellular signaling assays, proliferation studies, and morphometric analyses in HEK293T and NIH3T3 cell lines. Database analyses identified critical structural hotspots in neurofibromin (CSRD, GRD, and Armadillo1), whereas SPRED1 variants showed a more homogeneous distribution, suggesting distinct pathogenic mechanisms. In patient-derived NF1 and SPRED1 variants, energy-based analyses revealed a continuous spectrum in neurofibromin, ranging from haploinsufficiency to dominant-negative effects in late truncating variants, while SPRED1 alterations predominantly showed loss-of-function behavior. The in vitro cellular assays revealed distinct signaling dynamics depending on the type of variant analyzed in NF1 and SPRED1. Notably, ERK hyperactivation emerged as the most determinant molecular event for pathogenicity. Co-activation of p38 identified variants associated with more severe clinical outcomes, whereas the inverse p-ERK/p- AKT(Ser473) relationship revealed a negative feedback circuit between the MAPK and PI3K/AKT pathways. Cell-proliferation assays and quantitative cell-size analyses uncovered phenotypes consistent with the degree of MAPK deregulation, providing additional phenotypic biomarkers to discriminate between pathogenic and benign variants in both genes. The tissue relevance of HEK293T (epithelial/neuroectodermal contexts) and NIH3T3 (mesenchymal) cells allowed us to recapitulate the clinical heterogeneity observed in patients. The results of this doctoral thesis enabled the reclassification of variants of uncertain significance in both genes and identified ERK hyperactivation as a priority therapeutic target, supporting the use of MEK inhibitors in contexts consistent with this dysregulation. Taken together, this work establishes a comprehensive framework for the functional interpretation of variants in RASopathies and for the development of future personalizedmedicine strategies. Wed, 01 Jan 2025 00:00:00 GMT http://hdl.handle.net/10366/170354 2025-01-01T00:00:00Z http://hdl.handle.net/10366/170001 [ES] La enfermedad de Huntington (EH) es un trastorno neurodegenerativo que concurre con la acumulación de la proteína huntingtina mutante (mtHTT) en el cerebro. Aunque tradicionalmente se ha asociado con la pérdida progresiva de neuronas principalmente del estriado y en menor proporción en la corteza, evidencias recientes sugieren que los astrocitos también desempeñan un papel crucial en la etiogénesis y evolución de la enfermedad. En la EH, la disfunción del proceso autofágico contribuye a la acumulación de agregados de mtHTT, aunque aún se debate si los astrocitos participan activamente en esta alteración. La regulación de la autofagia, mediada por el sistema cannabinoide, emerge así como un mecanismo clave para comprender el progreso de la EH. Sin embargo, los efectos de los cannabinoides en esta enfermedad son controvertidos y parecen depender del tipo celular involucrado. En esta tesis doctoral, empleamos un enfoque genético mediado por partículas virales, para inducir de manera selectiva la expresión de HTT en astrocitos. El análisis de la proteostasis de agregación de HTT astrocítica in vitro, demostró que la activación cannabinoide por Δ9- tetrahidrocannabinol (THC) induce un proceso autofágico selectivo. Este medió de forma eficiente la disminución de agregados de mtHTT, así como la preservación de la función mitocondrial, mediada por mitofagia. In vivo, la expresión de mtHTT astrocítica reprodujo características clave de la EH, como gliosis, neurodegeneración y deterioro motor, que fueron prevenidas por THC. Nuestros hallazgos desafían la visión exclusivamente neurocéntrica de la EH y demuestran la relevancia patológica de la agregación de mtHTT astrocítica. El manejo de esta por el sistema cannabinoide resalta el potencial terapéutico de intervenir sobre la función astrocítica en el tratamiento de enfermedades neurodegenerativas. Wed, 01 Jan 2025 00:00:00 GMT http://hdl.handle.net/10366/170001 2025-01-01T00:00:00Z http://hdl.handle.net/10366/169995 [ES] Belantamab mafodotin (belamaf) es un conjugado anticuerpo-fármaco dirigido contra BCMA con una actividad prometedora para el mieloma múltiple en recaída/refractario (RRMM) en regímenes basados en combinaciones. Sin embargo, debido a su reciente introducción, aún no se conocen bien sus mecanismos de resistencia. Esta tesis tuvo como objetivo evaluar el potencial terapéutico de las combinaciones basadas en belamaf y esclarecer los mecanismos implicados en la resistencia adquirida, mediante modelos preclínicos y el análisis de datos clínicos. La combinación de belamaf con daratumumab mostró sinergia en líneas celulares de mieloma múltiple y modelos murinos, aumentando la citotoxicidad a dosis bajas y promoviendo la muerte celular inmunogénica. Para modelar la resistencia, se generaron líneas celulares resistentes a belamaf y se sometieron a análisis transcriptómicos y genómicos, que revelaron pérdida de expresión de BCMA y activación de vías asociadas a la respuesta inmune, la fosforilación oxidativa y la regulación del ciclo celular. La validación funcional demostró que la sobreexpresión estable de BCMA restauró completamente la sensibilidad a belamaf en uno de los modelos, mientras que en el otro solo se observó una recuperación parcial, lo que sugiere la implicación de mecanismos adicionales. Para explorar el impacto inmunológico de belamaf en un contexto clínico, se analizaron los perfiles inmunes de los pacientes incluidos en el ensayo GEM Bela-VRd, que evalúa la adición de belamaf al esquema estándar VRd (bortezomib, lenalidomida, dexametasona) en pacientes con mieloma múltiple de nuevo diagnóstico y candidatos a trasplante. Se observó una reducción de linfocitos totales y células T CD4+ en sangre periférica, sin evidencias de un fenotipo exhausto en las células efectoras. Los análisis exploratorios también mostraron una disminución progresiva de las células plasmáticas malignas y un aumento en la expresión de marcadores asociados con muerte celular inmunogénica. El recuento absoluto de linfocitos totales, células T CD8+ y células NK surgió como un posible biomarcador de respuesta, con valores más altos asociados a respuestas más profundas, tanto en el ciclo 3 como al final de la inducción. En conjunto, estos hallazgos aportan una justificación preclínica sólida para el desarrollo clínico de la combinación de daratumumab y belamaf. Paralelamente, nuestros análisis de inmunomonitorización en el ensayo GEM Bela-VRd subrayan la relevancia de seguir el perfil inmune durante el tratamiento, ofreciendo biomarcadores potenciales para guiar la evaluación de la respuesta en el mieloma múltiple.; [EN] Belantamab mafodotin (belamaf) is an antibody-drug conjugate targeting BCMA with promising activity for relapsed/refractory multiple myeloma (RRMM) in combination-based regimens. However, due to its recent introduction, its resistance mechanisms are not yet fully understood. This thesis aimed to evaluate the therapeutic potential of new belamaf-based combinations and to elucidate mechanisms underlying acquired resistance, both through preclinical models and clinical data analysis. The combination of belamaf and daratumumab exhibited strong synergy in multiple myeloma cell lines and mouse models, enhancing cytotoxicity at low doses and promoting immunogenic cell death. To model resistance, belamaf-resistant cell lines were generated and subjected to transcriptomic and genomic profiling, revealing BCMA loss, and activation of immune response, oxidative phosphorylation, and cell cycle regulation pathways. Functional validation demonstrated that stable overexpression of BCMA fully restored belamaf sensitivity in one model, while only partial restoration was observed in the other model of resistance, suggesting the implication of additional mechanisms. To further explore the immunological impact of belamaf in a clinical setting, we analyzed immune profiles from patients enrolled in the GEM Bela-VRd trial, which investigates the addition of belamaf to the standard VRd regimen (bortezomib, lenalidomide, dexamethasone) in newly diagnosed transplant-eligible MM patients. We observed a reduction in total lymphocyte and CD4+ T cells in peripheral blood, without producing an exhausted phenotype in effector cells. Exploratory analyses also showed a progressive reduction in malignant plasma cells and increased expression of markers associated with immunogenic cell death. Absolute counts of total lymphocytes, CD8+ T cells and NK cells emerged as potential biomarkers of response, with higher counts associated with deeper responses, both at cycle 3 and end of induction therapy. Together, these findings provide a strong preclinical rationale for the clinical development of the daratumumab and belamaf combination. In parallel, our immunomonitoring analyses within the GEM Bela-VRd clinical trial highlight the relevance of tracking immune profiles during treatment, offering potential biomarkers to guide response assessment in multiple myeloma. Wed, 01 Jan 2025 00:00:00 GMT http://hdl.handle.net/10366/169995 2025-01-01T00:00:00Z http://hdl.handle.net/10366/169721 [EN] This paper is concerned with the application of a Hybrid Algorithm (HA) to the determination of the Thermodynamic Activation Parameters (ATP) of a kinetic system of first order consecutive reactions. The 8 ATP’s parameters involved in the Arrhenius and Eyring equations have been directly determined from the non-isothermal kinetic data without prior knowledge of the rate constants. AH is constituted by a combination of two algorithms based on different mathematical principles which are sequentially applied. In a first step, a “soft modeling” method of Artificial Neural Networks (ANN) is applied and the obtained values of ATP’s parameters are used as initial estimates of a new optimization algorithm (AGDC) applied in a second stage to improve the values of the final parameters. The great success of HA is the efficient resolution of the ambiguity of the results obtained by ANN. In addition, comparing with the classic algorithms, which present the known weak points, HA offers important advantages: (a) the lack of necessity to know a priori the initial estimates since they are calculated from ANN application, (b) the low probability of being trapped at local minima, saddle points, etc. by means of the exhaustive control and suitable correction of the movement vector during the optimization process, and (c) the simultaneous determination of a higher number of parameters endowed with very different orders of magnitude. Thu, 01 Jan 2015 00:00:00 GMT http://hdl.handle.net/10366/169721 2015-01-01T00:00:00Z http://hdl.handle.net/10366/169483 [EN]This work describes the successful melt infiltration of poly(butylene succinate) (PBS) and poly(butylene adipate) (PBA) within 70 nm diameter anodic aluminum oxide (AAO) templates. The infiltrated samples were characterized by SEM, Raman, and FTIR spectroscopy. The crystallization behaviors and crystalline structures of both polymers, bulk and confined, were analyzed by differential scanning calorimetry (DSC) and grazing incidence wide angle X-ray scattering (GIWAXS). DSC revealed that a change in the nucleation process occurred from heterogeneous nucleation for bulk samples to homogeneous nucleation for infiltrated PBA and to surface-induced nucleation for infiltrated PBS. GIWAXS results indicate that PBS nanofibers crystallize in the α-phase, as well as their bulk samples. However, PBA nanofibers crystallize just in the β-phase, whereas PBA bulk samples crystallize in a mixture of α- and β-phases. The crystal orientation within the pores was determined, and differences between PBS and PBA were also found. Finally, broadband dielectric spectroscopy was applied to study the segmental dynamics for bulk and infiltrated samples. The glass temperature was found to significantly decrease in the PBS case upon infiltration, while that of PBA remained unchanged. These differences were correlated with the higher affinity of PBS to the AAO walls than PBA, in accordance with their nucleation behavior (surface-induced versus homogeneous nucleation, respectively). Tue, 26 Nov 2019 00:00:00 GMT http://hdl.handle.net/10366/169483 2019-11-26T00:00:00Z http://hdl.handle.net/10366/169465 [EN]Large bone defects are a significant health problem today with various origins, including extensive trauma, tumours, or congenital musculoskeletal disorders. Tissue engineering, and in particular bone tissue engineering, aims to respond to this demand. As such, we propose a specific model based on Elastin-Like Recombinamers-based click-chemistry hydrogels given their high biocompatibility and their potent on bone regeneration effect conferred by different bioactive sequences. In this work we demonstrate, using biochemistry, histology, histomorphometry and imaging techniques, the biocompatibility of our matrix and its potent effect on bone regeneration in a model of bone parietal lesion in female New Zealand rabbits. Fri, 30 Aug 2024 00:00:00 GMT http://hdl.handle.net/10366/169465 2024-08-30T00:00:00Z http://hdl.handle.net/10366/169463 [EN]The field of biomedicine relies on the development of advanced systems that mimic the extracellular matrix (ECM) to allow in vitro studies of cell–matrix interactions and subsequent implementation in vivo. The principalmatrices for biomedical applications are hydrogels, which are hydrophilic polymer networks that can absorb a large volume of water in resemblance to natural tissues (see Chapter 1). The materials used to obtain these biomimetic scaffolds include a large variety of synthetic polymers such as polyethylene glycol (PEG), as well as biopolymers, mostly proteins from animal tissues such as collagen (see Chapter 2). Combinations of natural and synthetic polymers have also been tested to improve the properties of hydrogels. Essential characteristics for the development of hydrogels for general biomedical applications include (i) an ability to provide a structural support to the surrounding cells, thus promoting natural and adequate cell growth that helps complete integration of the scaffold into the natural surrounding tissue and provides mechanical stability, (ii) an ability to mimic the ECM topography of tissues, (iii) an ability to mimic the natural environment so that cells can develop their normal functions and help restore damaged tissue, (iv) an ability to absorb and retain large quantities of water while maintaining their structures, thereby maintaining the hydration levels found in most tissues, (v) an ability to modulate their structures to match the shape and the size of defects, (vi) an ability to be easily manipulated, and, particularly, (vii) biocompatibility and biodegradability. Depending on the final application, hydrogels for use in regenerative medicine will need specific requirements in order to simulate the tissue to be repaired, such as cell adhesion or growth factors, which could also be included in the scaffold. Sat, 01 Jan 2022 00:00:00 GMT http://hdl.handle.net/10366/169463 2022-01-01T00:00:00Z http://hdl.handle.net/10366/169459 [EN]Despite lacking cooperatively folded structures under native conditions, numerous intrinsically disordered proteins (IDPs) nevertheless have great functional importance. These IDPs are hybrids containing both ordered and intrinsically disordered protein regions (IDPRs), the structure of which is highly flexible in this unfolded state. The conformational flexibility of these disordered systems favors transitions between disordered and ordered states triggered by intrinsic and extrinsic factors, folding into different dynamic molecular assemblies to enable proper protein functions. Indeed, prokaryotic enzymes present less disorder than eukaryotic enzymes, thus showing that this disorder is related to functional and structural complexity. Protein-based polymers that mimic these IDPs include the so-called elastin-like polypeptides (ELPs), which are inspired by the composition of natural elastin. Elastin-like recombinamers (ELRs) are ELPs produced using recombinant techniques and which can therefore be tailored for a specific application. One of the most widely used and studied characteristic structures in this field is the pentapeptide (VPGXG)n . The structural disorder in ELRs probably arises due to the high content of proline and glycine in the ELR backbone, because both these amino acids help to keep the polypeptide structure of elastomers disordered and hydrated. Moreover, the recombinant nature of these systems means that different sequences can be designed, including bioactive domains, to obtain specific structures for each application. Some of these structures, along with their applications as IDPs that self-assemble into functional vesicles or micelles from diblock copolymer ELRs, will be studied in the following sections. The incorporation of additional order- and disorder-promoting peptide/protein domains, such as α-helical coils or β-strands, in the ELR sequence, and their influence on self-assembly, will also be reviewed. In addition, chemically cross-linked systems with controllable order-disorder balance, and their role in biomineralization, will be discussed. Finally, we will review different multivalent IDPs-based coatings and films for different biomedical applications, such as spatially controlled cell adhesion, osseointegration, or biomaterial-associated infection (BAI). Sat, 01 Jan 2022 00:00:00 GMT http://hdl.handle.net/10366/169459 2022-01-01T00:00:00Z http://hdl.handle.net/10366/169455 [EN]Porous biomaterials are of significant interest in a variety of biomedical applications as they enable the diffusion of nutrients and gases as well as the removal of metabolic waste from implants. Pores also provide 3D spaces for cell compartmentalization and the development of complex structures such as vasculature and the extracellular matrix. Given the variation in the extracellular matrix composition across and within different tissues, it is necessary to tailor the physicochemical characteristics of biomaterials and or surfaces thereof for optimal bespoke applications. In this regard, different synthetic and natural polymers have seen increased usage in the development of biomaterials and surface coatings; among them, elastin-like polypeptides and their recombinant derivatives have received increased advocacy. The modular assembly of these molecules, which can be controlled at a molecular level, presents a flexible platform for the endowment of bespoke biomaterial properties. In this review, various elastin-like recombinamer–based porous biomaterials for both soft and hard tissue applications are discussed and their current and future applications evaluated. Fri, 01 Jan 2021 00:00:00 GMT http://hdl.handle.net/10366/169455 2021-01-01T00:00:00Z http://hdl.handle.net/10366/169428 [EN]This study evaluates the microstructure, porosity, mechanical properties and corrosion resistance of Ti-6Al-4V hip implant samples manufactured by Selective Laser Melting (SLM) and Electron Beam Melting (EBM), followed by different post-treatments (heat treatment and hot isostatic pressing -HIP-). Hydroxyapatite (HA) coatings were applied to enhance biocompatibility. Post-treated samples exhibited a lamellar α + β microstructure, with the EBM sample showing a coarser Widmanstätten structure, while acicular α' martensite was predominant in the as-built sample. The degree of porosity was lower than 0.2% in all samples. Microhardness was highest in the as-built sample (~ 400 HV) and lower in post-treated samples (~ 370 HV). Open Circuit Potential (OCP) tests indicated superior corrosion resistance for heat-treated samples, confirmed by Electrochemical Impedance Spectroscopy (EIS), where Sample E-HIP (HIP) showed a polarization resistance (Rpol) of 2490 kΩ/cm². In vitro tests confirmed that HA-coated samples exhibited excellent biocompatibility, slightly surpassing the Ti-6Al-4V samples. The HA-coated samples exhibited increased metabolic activity over 7 days, indicating superior biocompatibility. Finally, additive manufacturing combined with heat treatments and HA coatings effectively enhances Ti-6Al-4V for orthopaedic implants by improving the mechanical performance, corrosion resistance and biocompatibility. Wed, 23 Apr 2025 00:00:00 GMT http://hdl.handle.net/10366/169428 2025-04-23T00:00:00Z http://hdl.handle.net/10366/169001 [EN]Immune checkpoint inhibitors (ICIs) have improved cancer treatment; however, their use can be limited by immune-mediated adverse events, such as kidney damage. Diagnostic limitations of nephrotoxicity may lead to worsening of the patient's prognosis. This study aimed to validate a panel of urinary biomarkers as diagnostic tools for kidney damage in patients treated with ICIs. A prospective study was conducted on patients scheduled to receive ICIs. Those who subsequently developed kidney damage were considered cases; and those who did not were considered controls. A battery of biomarkers was assessed in urine samples at PRE-1, before the first treatment cycle; PRE-3, before the third cycle; and POST-3, 1 week after the third treatment cycle. A total of 46 patients participated in the study. At PRE-1, increased urinary excretion of IGFBP7, NAG, TIMP-2 × IGFBP7, and transferrin was observed in the case group, suggesting that these markers could be useful for early risk stratification of developing kidney damage. Furthermore, increased urinary excretion of albumin and NGAL was observed at PRE-3, suggesting that these markers could be of diagnostic utility to identify patients that could develop kidney damage once treatment is initiated. All of the aforementioned biomarkers demonstrated significant discriminatory ability between cases and controls, as verified by ROC curve analysis. The proposed biomarker battery could be used as a preventive tool for decision-making in the management of oncology patients at risk for kidney damage associated with ICIs. Furthermore, its use would allow personalized adjustment of therapy that would minimize the probability of renal complications even before starting the first cycle of treatment. Fri, 24 Oct 2025 00:00:00 GMT http://hdl.handle.net/10366/169001 2025-10-24T00:00:00Z http://hdl.handle.net/10366/167989 [EN]Simultaneous administration of certain antihypertensive (renin-angiotensin system inhibitors and diuretics) and nonsteroidal anti-inflammatory drugs (NSAIDs) is associated with a renal toxicity syndrome known as "triple whammy" acute kidney injury (TW-AKI), yet poorly characterized at the pathophysiological level, as no specific experimental model exists on which to conduct preclinical research. Herein, we generated and characterized a rat model of TW-AKI (0.7 mg/kg/day trandolapril +400 mg/kg/day ibuprofen +20 mg/kg/day furosemide). Double treatments involving the NSAID caused a subclinical acute kidney injury, as they reduced glomerular filtration rate to a significant but not sufficient extent to increase Crpl concentration. Only the triple treatment generated an overt AKI with increased Crpl provided that animals were under partial water ingestion restriction. Histological examination revealed no evidence of tissue renal injury, and no proteinuria or makers of renal damage were detected in the urine. These findings, along with a normal fractional excretion of sodium and glucose, indicated that these drug combinations produce a prerenal type of AKI. In fact, blood pressure and renal blood flow were also reduced (most markedly following the triple combination), although renal dysfunction was more pronounced than expected for the corresponding pressure drop, supporting a key pathological role of the interference with renal autoregulation mechanisms. In summary, prerenal TW-AKI only occurs when volemia is challenged (i.e., by furosemide in partially water-deprived animals) under the effects of renin-angiotensin system inhibitors and NSAIDs. This model will facilitate further pathophysiological knowledge for a better diagnosis and clinical handling of this syndrome. Mon, 27 Jul 2020 00:00:00 GMT http://hdl.handle.net/10366/167989 2020-07-27T00:00:00Z