Zinc pyrithione (ZnPT) and copper pyrithione (CuPT) are widely used antifouling booster biocides in the shipping industry as a replacement for the banned tributyltin (TBT). Sub-lethal effects of zinc pyrithione (ZnPT; 10 μg L⁻¹), copper pyrithione (CuPT; 10 μg L⁻¹) and combined copper–zinc pyrithione (CZPT; 5 + 5 and 10 + 10 μg. L⁻¹) to freshwater indicator mussel Unio crassus (5.49 ± 0.85 cm in size) were determined by investigation of the total hemocyte counts, biochemical analysis mussel tissues and histopathological observations after 48-h and 7-d exposures. Mean total hemocyte counts differed significantly among all groups, for both exposure durations. In the 7 d, lipid peroxidation levels (malondialdehyde, MDA nmol g⁻¹ wet tissue) and reduced glutathione levels (GSH μmol g⁻¹ wet tissue) were lower than 48 h. However, there were no significant differences among groups. Total protein levels (mg mL⁻¹) were approximately in the same range and differed only among 7-d exposure groups. The gill tissues showed hemocytic infiltration and lipofuscin like structures, while digestive gland showed loss of digestive tubules in the treatments of pyrithione compounds. Histopathological damages were most severe in the combined exposure groups. In conclusion, ZnPT, CuPT and combined CZPT_5/10 are highly toxic on a freshwater indicator mussel species U. crassus.

Curcumin; the major polyphenolic compound, isolated from Curcuma longa L.; loaded polyvinylpyrrolidone K90 fibers were prepared using electrospinning method. Effectiveness was tested on human colorectal adenocarcinoma cells with the presence of the endocrine disrupter Bisphenol A. Curcumin-loaded fibers were shown to have good physicochemical properties where excellent morphology of the electrospin fibers were formed. With the presence of 8 nM Bisphenol A, 17.37 mM fibers were found to inhibit proliferation in the cells in a dose-dependent manner. Fibers induced a significant increase in malondialdehyde by Thiobarbituric Acid Reactive Substances Assay compared to the control and this effect was supported by the presence of Bisphenol A. Western blot results indicate Super Oxide Dismutase-1 levels were increased by fiber, while Bisphenol A coincubated group resulted in a decrease. Fibers increased the expression of Estrogen Receptor 2, while Estrogen Receptor 1 expression did not change. Estrogen Receptor 2 expression was increased by coincubation with Bisphenol A; indicating a possible role of Estrogen Receptor 2 in the protective effects of fiber. This study presents that fiber had enhanced bioavailability and solubility with increased anticancer effect in human colon adenocarcinoma cells in presence of Bisphenol A; where involved mechanisms are antioxidant system and estrogen receptor expression.

Purpose: Inflammatory bowel disease (IBD) is a chronic inflammatory disorder requiring effective localized drug delivery to minimize systemic side effects. This study aimed to develop pH-responsive, Eudragit-based nanofiber formulations for colon-targeted oral delivery of hydrocortisone (HC). Methods: HC-loaded nanofibers were fabricated using the electrospinning technique with Eudragit ^® S100 and Eudragit ^® L100-55 polymers. Physicochemical characterization was performed using Differential Scanning Calorimetry (DSC), Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Diffraction (XRD), and Proton Nuclear Magnetic Resonance (¹H-NMR) analyses. Morphology, mechanical properties, contact angle, mucoadhesion, in vitro drug release, and ex vivo permeability were evaluated. Cytotoxicity and anti-inflammatory activity were assessed using RAW 264.7 macrophage cells. Results: XRD and DSC analyses indicated a reduction in the crystalline nature of HC within the nanofiber matrix, suggesting partial amorphization following electrospinning. The optimized formulation (E4) exhibited uniform morphology, suitable mechanical properties, and enhanced mucoadhesion. In vitro release studies demonstrated minimal drug release under gastric conditions (~ 11% at pH 1.2) and increased release at intestinal and colonic pH, confirming pH-responsive behavior. Ex vivo studies showed comparable permeability among formulations. Cell culture studies revealed that the formulations were non-cytotoxic (> 80% cell viability) and and significantly reduced TNF-α expression by approximately 39% at the protein level and showed a comparable reduction at the mRNA level. Conclusion: The developed Eudragit-based nanofiber system, particularly the E4 formulation, demonstrated effective colon-targeted delivery, favorable physicochemical properties, and significant anti-inflammatory activity. These findings indicate that HC-loaded nanofibers represent a promising platform for the localized treatment of IBD.