Exploring HSA Binding of Irinotecan-Functionalised Silver Nanoparticles: Insights from Spectroscopic and Calorimetric Approaches

• Published in: Journal of molecular liquids 2025-02, Vol.420, p.126796, Article 126796
• Main Authors: Raj, Aparna, Vidya, L., Aparna, V.M., Neelima, S., Sudarsanakumar, C.
• Format: Article
• Language: English
• Subjects: CD spectra; Green synthesis; Human serum albumin; Irinotecan; NanoITC; Silver nanoparticles
• ISSN: 0167-7322
• DOI: 10.1016/j.molliq.2024.126796

[Display omitted] •Irinotecan act as reducing and capping agents for the green synthesis of silver nanoparticles.•The IR-AgNPs are stable and spherical with a size range of 5–15 nm.•IR-AgNPs form a ground state complex with HSA.•Binding constant is in the order of 104 M−1.•The interaction is endothermic, entropy driven, and spontaneous. Silver nanomaterials are recognized for their therapeutic efficacy. Various research groups, including ours, have explored using different natural drugs as capping agents for silver nanoparticles. We have observed that these natural drug-functionalized nanoparticles show promising potential in biomedical applications. We are currently investigating a new silver nanoparticle utilizing irinotecan (IRN) as a capping and reducing agent. Our focus has been on studying their interaction mechanisms with human serum albumin (HSA), an abundant protein in the human body. We successfully prepared highly stable and spherical nanoparticles (IR-AgNPs) with a size range of 5–15 nm. Through UV–Visible and photoluminescence spectroscopy, we have confirmed the strong binding affinity of IR-AgNPs towards HSA. The binding constants determined from all the experiments fall within the range of 104 M−1. Isothermal titration experiments have revealed that the process is endothermic, entropy driven, and spontaneous. Despite the strong binding observed, Circular dichroism spectroscopy analysis indicates minimal unwinding of the secondary structure and negligible conformational changes in HSA upon interaction with IR-AgNPs. In conclusion, our comprehensive study proposes that the interaction of IR-AgNPs and HSA is robust, with minimal impact on the protein’s conformation. The study highlights the stability and safety of these nanoparticles for potential therapeutic applications, particularly in drug delivery.