7‑Amino-6H-anthra[9,1-cd] Isothiazol-6-one-Casein Nanosystem for Live Cell Staining and Augmenting Therapeutic Effectiveness in Triple Negative Breast Cancer

Triple negative breast cancer (TNBC) causes a significant challenge in oncology due to its aggressive nature and limited treatment options. This study introduces a promising strategy to enhance therapeutic effectiveness against TNBC by developing a dual-functioning 7-amino-6H-anthra[9,1-cd] isothiazol-6-one (AAT) encapsulated Casein nanosystem (CAAT NPs). This innovative approach serves both as a live cell staining technique and as a means to augment therapeutic outcomes in highly metastatic TNBC. AAT, chosen for its dual role as a fluorescence marker for live cells and its inherent anticancer properties, undergoes fluorescence quenching upon inducing cancer cell death. The Casein nanosystem ensures efficient dye encapsulation, providing stability and controlled release. Physicochemical analysis validates successful encapsulation, yielding a desirable size distribution of CAAT NPs. Cellular uptake studies demonstrate effective internalization in 4T1 cells with minimal cytotoxicity in healthy cell lines and organisms. Subsequent investigations revealed subcellular localization, altered mitochondrial membrane potential, nucleus breakage, antimigration activity, and growth suppression in 4T1 cells. Increased expression of γH2AX, indicating DNA damage, further underscores the therapeutic potential. In a 3-D model of 4T1 cells, CAAT NPs exhibit significant therapeutic efficacy, suggesting a promising option for safe and efficient TNBC treatment

Amyloidogenic Propensity of Metabolites in the Uric Acid Pathway and Urea Cycle Critically Impacts the Etiology of Metabolic Disorders

Novel insights into the etiology of metabolic disorders have recently been uncovered through the study of metabolite amyloids. In particular, inborn errors of metabolism (IEMs), including gout, Lesch–Nyhan syndrome (LNS), xanthinuria, citrullinemia, and hyperornithinemia–hyperammonemia–homocitrullinuria (HHH) syndrome, are attributed to the dysfunction of the urea cycle and uric acid pathway. In this study, we endeavored to understand and mechanistically characterize the aggregative property exhibited by the principal metabolites of the urea cycle and uric acid pathway, specifically hypoxanthine, xanthine, citrulline, and ornithine. Employing scanning electron microscopy (SEM), transmission electron microscopy (TEM), and atomic force microscopy (AFM), we studied the aggregation profiles of the metabolites. Insights obtained through molecular dynamics (MD) simulation underscore the vital roles of π–π stacking and hydrogen bonding interactions in the self-assembly process, and thioflavin T (ThT) assays further corroborate the amyloid nature of these metabolites. The in vitro MTT assay revealed the cytotoxic trait of these assemblies, a finding that was substantiated by in vivo assays employing the Caenorhabditis elegans (C. elegans) model, which revealed that the toxic effects were more pronounced and dose-specific in the case of metabolites that had aged via longer preincubation. We hence report a compelling phenomenon wherein these metabolites not only aggregate but transform into a soft, ordered assembly over time, eventually crystallizing upon extended incubation, leading to pathological implications. Our study suggests that the amyloidogenic nature of the involved metabolites could be a common etiological link in IEMs, potentially providing a unified perspective to study their pathophysiology, thus offering exciting insights into the development of targeted interventions for these metabolic disorders