An <i>in-vitro</i> quantitative investigation on the synergistic effect of capsaicin and 5-fluorouracil encapsulated into lipid nanocapsules to treat breast cancer

Breast cancer conventional therapeutics are effective; however, they encounter some limitations including multidrug resistance, the presence of pharmacological barriers, and non-selectivity which hinder their optimal therapeutic efficacy. Overcoming such drawbacks necessitates the development of efficient drug vehicles including lipid-based nanoparticles. This study aimed to quantitatively investigate in-vitro the synergistic therapeutic effect of the novel combination of capsaicin and 5-fluorouracil (5-FU) encapsulated in lipid nanocapsules (LNCs). To this end, thorough physicochemical and in-vitro assessments on the breast cancer cell line (MCF-7) were done. The drug-loaded LNCs were characterized using DLS, TEM imaging, stability study, and in-vitro release study. Furthermore, the biological activity of the prepared LNCs was assessed by implementing comparative cytotoxicity studies as well as apoptosis, and cell cycle flow cytometric analyses. The developed nanoformulations were monodisperse with average particle size (PS) of 31, 43.8, and 127.3 nm for empty LNCs, Cap-LNCs, and 5-FU-LNCs, respectively, and with a surface charge of −35.4, −21.7 and −31.4 mV, respectively, reflecting good physical stability. The TEM micrographs revealed the spherical morphology of the drugs-loaded LNCs with comparable PS to that obtained by DLS. on the other hand, all the biological assessments confirmed the superior antiproliferative effect of the combined drug-loaded LNCs over their free drug counterparts. Intriguingly, the study findings highlighted the potential synergistic activity of the drugs (capsaicin and 5-FU) and the extensive enhancement of their biological activity through incorporation into LNCs. Such promising results will pave the way to further novel combined nanoformulation in preclinical and clinical studies on breast cancer patients.</p

Design and Characterization of Compact, Programmable, Multistranded Nonimmunostimulatory Nucleic Acid Nanoparticles Suitable for Biomedical Applications

We report a thorough investigation of the role of single-stranded thymidine (ssT) linkers in the stability and flexibility of minimal, multistranded DNA nanostructures. We systematically explore the impact of varying the number of ssTs in three-way junction motifs (3WJs) on their formation and properties. Through various UV melting experiments and molecular dynamics simulations, we demonstrate that while the number of ssTs minimally affects thermodynamic stability, the increasing ssT regions significantly enhance the structural flexibility of 3WJs. Utilizing this knowledge, we design triangular DNA nanoparticles with varying ssTs, all showing exceptional assembly efficiency except for the 0T triangle. All triangles demonstrate enhanced stability in blood serum and are nonimmunostimulatory and nontoxic in mammalian cell lines. The 4T 3WJ is chosen as the building block for constructing other polygons due to its enhanced flexibility and favorable physicochemical characteristics, making it a versatile choice for creating cost-effective, stable, and functional DNA nanostructures that can be stored in the dehydrated forms while retaining their structures. Our study provides valuable insights into the design and application of nucleic acid nanostructures, emphasizing the importance of understanding stability and flexibility in the realm of nucleic acid nanotechnology. Our findings suggest the intricate connection between these ssTs and the structural adaptability of DNA 3WJs, paving the way for more precise design and engineering of nucleic acid nanosystems suitable for broad biomedical applications