This study reports four acidity constants of the anticancer drug doxorubicin (DOX) and its order of deprotonation, which have not been reported previously; a mathematical model has also been proposed to predict the percentage of DOX intercalation over laponite clay (Lap) at different pH values. The pKa values were determined experimentally and using the Stability Quotients from Absorbance Data (SQUAD) software, whilst the order of deprotonation was determined using Density Functional Theory (DFT). The calculated pKa values were: 8.38 ± 0.11, 10.29 ± 0.10, 11.05 ± 0.07, and 13.90 ± 0.03 with proton loss beginning at the primary amine, followed by two protons located in the hydroxylated anthraquinone structure, and finally from the short side chain with a carbonyl group. The interaction between DOX and Lap was also studied using UV–vis spectrophotometry and electrochemical techniques. Using spectrophotometry, the logarithms of the binding constants (log Kcond) corresponding to the DOX-Lap complexes were calculated: 5.039 ± 0.009, 4.845 ± 0.002, and 4.618 ± 0.010 at pH values of 1.50 ± 0.01, 7.40 ± 0.01, and 12.50 ± 0.01, respectively. From the log Kcond graph versus pH, a linear relationship “log Kcond = −0.0351*pH + 5.0952” was obtained, used to construct a three-dimensional diagram (molar percentage-pLap-pH) to predict the percentage of DOX intercalation. The high affinity of DOX for this nanoclay was confirmed through cyclic voltammetry. This knowledge may be used to improve the experimental design of controlled-release nanoparticle systems in which clays are used as carriers.
Reconstituted high-density lipoproteins (rHDL) are promising nanocarriers for theranostic applications in oncology due to their tumour-targeting capabilities through SR-B1 receptor recognition. DOTA-modified rHDL enables radiolabelling with several radiometals for imaging and therapy. However, comprehensive dosimetric data comparing multiple radionuclides are lacking. In this work, absorbed doses in healthy organs from DOTA-rHDL radiolabelled with 177Lu were calculated. Such doses were also estimated using radionuclides for potential theranostic applications such as 47Sc, 52Mn, 67Cu, 67Ga, 89Zr, 111In and 155Tb which half-lives are shorter but close to that of 177Lu. DOTA-rHDL nanoparticles were prepared according to a previous method and characterised by dynamic light scattering. Biodistribution studies were conducted in healthy CD-1 mice at multiple time points (2, 24, 48, and 120 h post-injection) following intravenous administration of DOTA-rHDL radiolabelled with 177Lu. Biokinetic and time-activity models were generated for major organs, and absorbed doses were calculated based on the Medical Internal Radiation Dose (MIRD) formalism, with organ masses adjusted to human physiology. From the biokinetic models, time-activity models for the radionuclides 47Sc, 52Mn, 67Cu, 67Ga, 89Zr, 111In and 155Tb were also generated and absorbed doses calculated.All radionuclides showed accumulation in the liver, kidneys, and spleen, consistent with reticuloendothelial system (RES) clearance. 52Mn-DOTA-rHDL exhibited the highest absorbed doses in all organs due to its high-energy, and high-abundance gamma ray emissions while 67Ga and 111In demonstrated more favourable dosimetric profiles. Blood clearance exhibited biphasic kinetics with biological half-lives varying among radionuclides. This comparative dosimetric analysis provides crucial data for selecting suitable radionuclides for DOTA-rHDL-based theranostics. The absorbed doses in healthy organs are within acceptable limits, supporting the clinical translation potential of DOTA-rHDL nanoparticles.
The growing demand for clean water is driving the development of sustainable technologies for dye removal from wastewater. In this study, recycled polylactic acid (PLA) films and PLA-CeO₂ nanocomposites were investigated as catalytic media for plasma-assisted degradation of methylene blue (MB). Before degradation experiments, the films were surface-activated using an atmospheric-pressure corona discharge. The use of recycled PLA contributes to waste valorization within a circular economy framework. Surface analyses by Raman spectroscopy, X-ray diffraction (XRD), and atomic force microscopy (AFM) showed that plasma activation induces chain scission, increases crystallinity, and enhances surface roughness in PLA films. In PLA-CeO₂ nanocomposites, plasma treatment increases nanoparticle accessibility while preserving polymer structural integrity. Methylene blue degradation was carried out in a continuous flow plasma-liquid system using an atmospheric-pressure air corona discharge. Under these conditions, plasma-treated PLA films served as catalysts, achieving complete MB degradation ( 100
The study reports the efficient copper-catalyzed synthesis of a novel hybrid triazole, 1-adamantyl-4-ferrocenyl-5H-1,2,3-triazole 1, featuring transition-metal redox activity. Structural analysis via single-crystal X-ray diffraction and Hirshfeld Surface confirmed a slight twist between the triazole and ferrocenyl rings, with crystal packing forming one-dimensional chains through weak C-H-N hydrogen bonds. The compound was characterized by NMR, FT-IR, DART-MS, UV-Vis, elemental analysis and optical rotation. Electrochemical studies showed single oxidation and reduction peaks at Ep(a) = 0.150 V and Ep(c) = 0.083 V (vs. Fc/Fc+), resulting in a differential potential of 0.065 V and standard potential of 0.116 V. Chronoamperometry yielded a diffusion coefficient of D approximate to 3.0 & times; 10-6 cm2 & centerdot;s-1. Spectroelectrochemistry revealed a new absorption band at 720 nm linked to interactions involving Fe & sup3;+. TD-DFT calculations indicated an optical gap of 2.33 eV at 533 nm, with HOMO/LUMO energies estimated at -6.61 eV and -4.28 eV.
Passenger transport, and particularly student transport, tends to become saturated due to on one side the growing increase and distribution of the student population, and the other the few available buses. This article proposes the use of clustering processes through the Density-Based Spatial Clustering of Applications with Noise algorithm, alongside cluster quality assessment metrics, to establish suitable bus stops. Additionally, a convex hull is employed to determine the subset of bus stops from which the transport routes will start, called terminals. Based on the elements identified through clustering and the convex hull, the parameters and dataset required for an Integer Linear Programming model were defined. In order to generate appropriate transport routes for each available bus, the model incorporates constraints based on the Vehicle Routing Problem. Furthermore, decision variables and constraints were defined to transport the maximum number of students to their designated destinations by means of the Maximum Flow Problem, resulting in a multi-objective function aimed at finding routes with minimum cost and maximum student flow per bus, and also incorporating departure times. The transport service at the Autonomous University of the State of Mexico was used as a case study to test the proposal. The model was solved using the COIN-OR Branch and Cut solver, which enabled the determination of optimal routes for each bus, successfully transporting the highest possible number of students to their respective destinations at minimal (time) cost, and ensuring that all routes start and end at appropriate times, in accordance with student entry schedules.
