Miguel Ángel Méndez Rojas

Superparamagnetic iron oxide nanoparticles (SPIONs) present significant potential for magnetic fluid hyperthermia (MFH) therapies, owing to their high magnetic saturation, superior colloidal stability, and crystallinity. This work reports the solvothermal synthesis of Zn‐doped Fe ₃ O ₄ nanoparticles, which demonstrated high crystallinity and a saturation magnetization of 71.40 emu g ⁻¹ . Under alternating magnetic fields (AMFs), a suspension of these nanoparticles (15 mg mL ⁻¹ ) achieved temperature increments of 11.65°C and 23.92°C at applied field conditions of 166.12 kHz/13.24 kA m ⁻¹ and 263.6 kHz/13.91 kA m ⁻¹ , respectively. These MFH conditions subsequently induced the release of ferrous/ferric ions at concentrations of 3.76 and 11.86 mg L ⁻¹ . The efficacy of the MFH treatment, driven by the nanoparticles, was evaluated against the pathogens Pseudomonas aeruginosa (thermoresistant bacteria) and Candida albicans . The study revealed a biphasic antimicrobial mechanism: initially, microbial growth occurs due to the release of iron ions, which microbes use for natural survival; this is followed by cytotoxic effects, combined with direct thermal ablation and the generation of reactive oxygen species (ROS), resulting in potent microbial inhibition.

Ultrafine particles (≤100 nm) and other environmental nanoparticles have emerged as biologically active pollutants that can cross biological barriers, including the blood–brain barrier and the placenta. Growing evidence implicates ultrafine particles in a wide range of neuropsychiatric conditions, yet their effects remain poorly integrated into clinical and public health frameworks. In this review, we distinguish between size-defined ultrafine particles (UFPs, ≤100 nm), composition-defined environmental nanoparticles originating from combustion and secondary formation processes, and engineered nanomaterials (ENPs), which differ in physicochemical properties, exposure scenarios, and regulatory status. This narrative systematic review synthesizes findings from human and experimental studies on the neuropsychiatric and neurodevelopmental effects of environmental nanopollutants. A structured search was conducted in PubMed, Web of Science, Scopus, and Google Scholar up to November 2025, following explicit inclusion and exclusion criteria. Eligible studies included peer-reviewed human and animal research assessing mental health or neurological outcomes of nanopollutant exposure. Epidemiological studiesprimarily involving traffic-related air pollution and mixed combustion-derived ultrafine particle exposuressuggest associations with increased risk of cognitive impairment, autism spectrum disorder, depression, schizophrenia, and neurodegenerative diseases, including Alzheimer’s, Parkinson’s, and amyotrophic lateral sclerosis. Prenatal and early life exposures were linked to cortical thinning, altered neurodevelopmental trajectories, and early proteinopathies. Underlying mechanisms include neuroinflammation, oxidative stress, and protein aggregation. Despite methodological heterogeneity, the evidence supports the urgent need for regulation and prevention. Environmental nanopollutants constitute an under-recognized, modifiable risk factor for neuropsychiatric and neurodegenerative conditions. A paradigm shift is needed to incorporate environmental exposure history into mental health research, risk assessment, and prevention strategies. Regulatory action targeting nanopollutant emission and exposure, particularly in vulnerable populations, is critical to mitigating long-term neurological consequences.

Research on hydrogen (H₂) production has been intensively investigated due to the critical need for transitioning from fossil fuels to cleaner energy sources. This study demonstrates a dual-purpose approach where water pollutant degradation and H₂ production occur simultaneously, eliminating the need for sacrificial materials and reducing costs. CuO-TiO₂ calcined xerogels were employed in solutions containing NaOH and acid black dye 1 (AB1). The CuO-TiO₂/AB1/NaOH system successfully degraded recalcitrant pollutants while producing H₂ under optimized conditions. H₂ evolution occurred at the photocatalyst holes due to AB1’s lower potential compared to water, while AB1 decomposition proceeded via O2^•− radical formation. X-ray diffraction (XRD) and Scanning Electron Microscope (SEM) analyses showed sponge-like structures with 20 nm crystals. Polarization curves confirmed H₂ generation in the cathodic region. Bode diagrams of the CuO-TiO₂/AB1/NaOH system (0.3 M NaOH and 60 mg/L AB1) exhibited noble/passive behavior, consistent with the polarization curve data. Using 0.3–0.4 M NaOH and 60 mg/L AB1, 636–647 ppb H₂/g_catalyst was produced in 60 min, and only 0.07 mg/L AB1 was left as indicated by absorbance measurements at 618 nm. H₂ evolution decreased as dye degradation increased. The best system for dye degradation has a k constant of 0.066 min⁻¹ and R² of 0.99, contains 40 mg/L AB1, and runs at 40 °C, whereas the maximum dual performance required 0.5 M NaOH, yielding 5050 ppb H₂/g_catalyst.

Background: In tissue engineering, developing injectable hydrogels with tailored mechanical and bioactive properties remains a challenge. This study introduces an injectable hydrogel composite for soft tissue regeneration, composed of oxidized alginate (OA) and N-succinyl chitosan (NSC) cross-linked via Schiff base reaction, reinforced with graphene oxide (GOx) and cyclic arginylglycylaspartic acid (c-RGD). The objective was to create a multifunctional platform combining injectability, bioactivity, and structural stability. Methods: The OA/NSC/GOx-cRGD hydrogel was synthesized through Schiff base cross-linking (aldehyde-amine reaction). Characterization included FTIR (C=N bond at 1650 cm⁻¹), Raman spectroscopy (D/G bands at 1338/1567 cm⁻¹), SEM (porous microstructure), and rheological analysis (shear-thinning behavior). In vitro assays assessed fibroblast viability (MTT) and macrophage TNF-α secretion (ELISA), while ex-vivo injectability and retention were evaluated using chicken cardiac tissue. Results: The hydrogel exhibited shear-thinning behavior (viscosity: 10 to G″), ensuring injectability. SEM revealed an interconnected porous structure mimicking native extracellular matrix. Fibroblast viability remained ≥95%, and TNF-α secretion in macrophages decreased by 80% (30 vs. 150 pg/μL in controls), demonstrating biocompatibility and anti-inflammatory effects. The hydrogel adhered stably to cardiac tissue without leakage. Conclusions: The OA/NSC/GOx-cRGD composite integrates injectability, bioactivity, and structural stability, offering a promising scaffold for tissue regeneration. Its modular design allows further functionalization with peptides or growth factors. Future work will focus on translational applications, including scalability and optimization for dynamic biological environments.

En los últimos años, el avance alcanzado en el desarrollo de las aplicaciones biomédicas se ha dado de forma significativa, debido principalmente, al gran esfuerzo que ha tenido la comunidad científica internacional en temas relacionados a la nanociencia y nanotecnología, en especial en el estudio y desarrollo de nanopartículas, las cuales son estructuras que tienen tamaños menores a los 100 nanómetros. Las nanopartículas están conformadas por unos pocos cientos de átomos, lo que genera que sus propiedades sean únicas y cambien considerablemente a nivel macrométrico. Dentro de la familia de materiales nanoestructurados, con propiedades únicas, se encuentran las nanopartículas de carbono, las cuales son muy versátiles debido a que presentan diferentes tipos de estructuras. Esto las convierte en extraordinarias opciones para su uso como transportadores de fármacos, lo cual las hace una prominente opción para su uso en el área oncológica, en especial para los tratamientos contra cáncer. En este trabajo exploramos el fascinante mundo de los nanomateriales, con propiedades excepcionales para la liberación de fármacos. Tales como las sorprendentes nanoestructuras de carbono, compuestas por nanotubos y grafeno, con resistencia y biocompatibilidad ideales para aplicaciones biomédicas. La importancia principal es que estos avances prometedores anticipan una revolución en el diagnóstico, tratamiento y prevención de enfermedades, lo cual en un futuro puede llegar a redefinir el futuro de la medicina.

The ubiquity of nanoparticles, sourced from both natural environments and human activities, presents critical challenges for public health. While offering significant potential for innovative biomedical applications—especially in enhancing drug transport across the blood–brain barrier—these particles also introduce possible hazards due to inadvertent exposure. This concise review explores the paradoxical nature of nanoparticles, emphasizing their promising applications in healthcare juxtaposed with their potential neurotoxic consequences. Through a detailed examination, we delineate the pathways through which nanoparticles can reach the brain and the subsequent health implications. There is growing evidence of a disturbing association between nanoparticle exposure and the onset of neurodegenerative conditions, highlighting the imperative for comprehensive research and strategic interventions. Gaining a deep understanding of these mechanisms and enacting protective policies are crucial steps toward reducing the health threats of nanoparticles, thereby maximizing their therapeutic advantages.