The integration of multiple functionalities into single theranostic platforms offers new opportunities for personalized and minimally invasive clinical interventions, positioning these materials as highly promising tools in modern medicine. Thereby, magneto-luminescent Janus-like nanoparticles (JNPs) were developed herein, and encapsulated into near-infrared (NIR) light- and pH- responsive micelle-like aggregates (Mic) for simultaneous magnetic targeting, biomedical imaging, photothermal therapy, and pH- NIR-light activated drug delivery. The JNPs consisted of NaYF₄:Yb,Tm upconverting nanoparticles (UCNPs) on which a well-differentiated magnetite structure (MNPs) grew epitaxially. JNPs were encapsulated together with doxorubicin (Dox) into micelle-like aggregates formed with the stimuli-responsive Poly(NIPAM-co-Spiropyran) copolymer, which responds to UV light, temperature changes, and pH variations, so as to form the JNP-Dox@Mic nanocarrier. Based on physicochemical characterizations, the mechanism for the NIR-activated release of Dox from the JNP-Dox@Mic aggregates is suggested: i) activation of the upconverting emissions with 975 nm light, ii) energy transfer to the material's lattice via nonradiative relaxation, inducing a local temperature increase, iii) resonance energy transfer (RET) from the UV-emission bands to the micelle-like aggregates, and iv) reversible isomerization of the hydrophobic Spiropyran (SP) moiety to a hydrophilic zwitterionic merocyanine (MC) form, leading to Dox delivery. Furthermore, the strong light-to-heat conversion ability of the JNPs was demonstrated through thermal imaging analysis, reaching temperatures up to 108 °C upon irradiation for 60 seconds. The efficacy of these nanocomposites for pH- and NIR-light-induced controlled release was demonstrated using electrophoretic separations and tested against MCF-7 breast cancer cells. While non-irradiated samples of JNP-Dox@Mic were innocuous up to 200 μg.mL^-1, irradiation with 975 nm light for 5 minutes reduced cell viability to 26 %. These findings highlight the effective synergy between JNPs and micelle-like aggregates, resulting in versatile heterostructures that could be evaluated for multimodal therapy and imaging strategies.

Growing concern over nanoplastics as emerging pollutants calls for effective treatment methods, with advanced oxidation processes (AOPs) showing strong potential for their degradation. This study examines the interaction between polyethylene terephthalate nanoplastics (PET-NPs) and magnetite nanoparticles (MNPs) in a heterogeneous Fenton-like system, focusing on colloidal behavior, hydroxyl radicals (^●OH) generation, and potential degradation pathways. Zeta potential (ZP) and particle diameter measurements were used to characterize nanoparticle dispersion and aggregation mechanisms over a pH range of 3–9.5. The results revealed a pronounced pH-dependent stability, with MNPs exhibiting larger hydrodynamic diameters (283 nm) and lower stability at pH 3 (ZP: −9.8 mV) compared with neutral or alkaline conditions (189 nm; ZP: −44 to −42 mV). PET-NPs exhibited minimal agglomeration at a pH of 9.5 (ZP: −25.6 mV). Unlike conventional Fenton systems, ^●OH production peaked at pH 7–9.5 (0.3–0.35 μM), attributed to preserved Fe²⁺ sites and reduced particle agglomeration. Although PET-NPs resisted oxidative degradation, their aggregation with MNPs enabled magnetic recovery (46% efficiency at pH 3) through charge screening, Fe³⁺/Fe²⁺ bridging, and hydrophobic interactions. These findings highlight MNPs’ potential for sustainable nanoplastic separation and emphasize the need for optimized catalysts to enhance ^●OH-driven degradation. Overall, this work advances understanding of nanoplastic–magnetite interactions and offers insights into AOP applications.

Dans le domaine de la nanomédecine, de nouveaux outils nanotheranostiques sont développés pour la détection, le suivi et le traitement simultanés des maladies. Par conséquent, ce travail explore la synthèse de nanomatériaux théranostiques composés de nanoagrégats polymères de type micelle (Mic) sensibles au pH et à la lumière, capables de charger et de libérer des médicaments, et de nanoparticules hybrides de type Janus avec des propriétés magnétiques et luminescentes, à des fins de guidage spécifique, thérapeutiques et d'imagerie. L'optimisation de l'auto-assemblage des Mic sensibles au pH et à la lumière a été réalisée à l'aide de méthodologies complémentaires, telles que la DLS, la TEM et l'électrophorèse capillaire (EC). L'EC a également été utilisée pour quantifier la charge de doxorubicine (DOX) dans le MIc et sa libération par stimulation. En outre, la synthèse et l'optimisation de nanoparticules hybrides de type Janus (JNPs) présentant une luminescence à conversion ascendante et des propriétés magnétiques ont été réalisées. Ensuite, les JNPs ont été encapsulées avec la DOX dans le Mic, et la capacité de chargement et de libération de ce nanosystème a de nouveau été évaluée par EC. De plus, sous irradiation proche infra-rouge, ces JNPs émettent de la lumière UV. Ceci implique la modification de la structure moléculaire des Mic permettant la libération de médicaments. Ces résultats soulignent l'intérêt de tels nanosystèmes hybrides pour des applications théranostiques in vivo.

La ciencia es la clave para resolver muchos problemas, y la economía circular es esencial para mantener nuestro modelo económico actual. Sin embargo, aquellos que poseen el conocimiento para solucionar problemas medioambientales a menudo no pueden aplicarlo debido a las dificultades para emprender en su situación laboral. Al mismo tiempo, los emprendedores y empresarios a menudo no implementan las soluciones necesarias porque no ven beneficios inmediatos. La economía circular abarca desde la innovación científica y tecnológica hasta la venta de productos, integrando todo el ciclo de producción. En este capítulo, analizamos un caso práctico que va desde una idea y una innovación científica hasta el proceso de venta del producto, destacando los desafíos de un emprendimiento socioambiental. Nos centramos en cómo comercializar un emprendimiento basado en la reutilización de residuos, usando como ejemplo el “bagazo de café”.

Advanced oxidation processes (AOPs) have emerged as technologies for the removal of pollutants in water systems due to their ability to generate hydroxyl radical (•OH). However, the catalytic behavior and synergistic interactions of hybrid nanomaterials in different AOPs remain insufficiently quantified. In this study, TiO₂-Fe₃O₄ hybrid nanoparticles (HNPs) were synthesized through a hydrothermal method and evaluated in Fenton, photocatalysis, and photo-Fenton processes. Three formulations (TiO₂ to Fe₃O₄ 1:1, 1:0.5, and 1:0.25) were prepared to investigate the influence of content on catalytic activity by indirectly quantifying •OH generation through 7-hydroxycoumarin formation. Physicochemical, structural and magnetic characterization shows a possible formation of core–satellite like and Janus-like HNPs with superparamagnetic behavior. Among the evaluated catalysts, the HNP-0.25 formulation exhibited the highest catalytic activity under photo-Fenton conditions, achieving a •OH generation rate of 0.11052 µmol min⁻¹ g⁻¹ and a synergy index of 11.26, which indicates a cooperative interaction between photocatalytic and Fenton pathways. Furthermore, the optimized HNPs demonstrated high degradation efficiency toward pollutants, achieving 99% degradation of methylene blue (k = 0.1528 min⁻¹) and 97% removal of ciprofloxacin (k = 0.0699 min⁻¹) after 50 min under photo-Fenton conditions. These findings demonstrate that the composition and hybrid nature of TiO₂-Fe₃O₄ nanoparticles play a critical role in promoting synergistic AOP interactions, enhancing •OH generation and pollutant degradation efficiency.