Enhanced Hydrodynamic Radius of AOT/n-heptane/Water Reverse Micellar System Through Altered Electrostatic Interactions and Molecular Self-Assemblies

Evaluating the efficacy of Rose Bengal-PVA combinations within PCL/PLA implants for sustained cancer treatment

The current investigation aims to address the limitations of conventional cancer therapy by developing an advanced, long-term drug delivery system using biocompatible Rose Bengal (RB)-loaded polyvinyl alcohol (PVA) matrices incorporated into 3D printed polycaprolactone (PCL) and polylactic acid (PLA) implants. The anticancer drug RB's high solubility and low lipophilicity require frequent and painful administration to the tumour site, limiting its clinical application. In this study, RB was encapsulated in a PVA (RB@PVA) matrix to overcome these challenges and achieve a localised and sustained drug release system within a biodegradable implant designed to be implanted near the tumour site. The RB@PVA matrix demonstrated an RB loading efficiency of 77.34 ± 1.53%, with complete RB release within 30 min. However, when integrated into implants, the system provided a sustained RB release of 75.84 ± 8.75% over 90 days. Cytotoxicity assays on PC-3 prostate cancer cells indicated an IC50 value of 1.19 µM for RB@PVA compared to 2.49 µM for free RB, effectively inhibiting cancer cell proliferation. This innovative drug delivery system, which incorporates a polymer matrix within an implantable device, represents a significant advancement in the sustained release of hydrosoluble drugs. It holds promise for reducing the frequency of drug administration, thereby improving patient compliance and translating experimental research into practical therapeutic applications.

Spectroscopy study of dimerization of fluorone dyes in AOT reverse micelles

The dimerization processes and its thermodynamic parameters of fluoronic dyes (fluorescein (F), eosin (E), erythrosine (ER), bengal rose (BR)) in reverse micelles of AOT with different hydrodynamic radius R_h are studied. The dimerization constants and its efficiency (the degree of dimerization of dye molecules (1-X)) were determined from the experimental data. It is found that an increase in the intercombination conversion due to the heavy atom effect leads to an increase of the value of (1-X). At the same time, the heavy atom effect affects the dye dimerization process for all the studied values of R_h. The linear dependence of (1-X) on R_h is observed. The slope of this dependence is affected by both the mass of the internal heavy atom and the charge of the anionic forms of dyes. It was found that there is a different structure of dye dimers for different R_h for all the studied systems - different angles α between the molecules in the dimer. A linear dependence of α on R_h is observed. At the same time, the growth gradients α(R_h) practically do not differ for F, E, and BR and they are of the greatest importance for the studied water-micellar solutions of dyes. The growth of α from R_h is insignificant for ER. The thermodynamic parameters (such as Gibbs potential ΔG, enthalpy (ΔH and entropy ΔS) were calculated from the experimentally measured dependences of the dimerization constant on the temperature. ΔH < 0 and ΔS < 0 in micellar solutions of the studied dyes at all values of R_h, that indicates that the dimerization reaction in the studied systems is controlled by enthalpy. The obtained linear relationship between TΔS and ΔH indicates the existence of enthalpy-entropy compensation in the dimeric reactions of the molecules of the studied dyes. The linear correlation observed between the values of TΔS and ΔH allowed us to establish that the higher the molecular weight of the halogen in the dye molecule, the more effectively an increase in ΔH contributes to the dimeric stability.