Human Serum Albumin-Based Nanoparticles for Targeted Intracellular Drug Delivery

We report the synthesis and characterization of folic acid (FA)-conjugated human serum albumin nanoparticles, (HSA-FA):Ru NPs, as targeted carriers for rutin (Ru), a flavonoid with known anticancer activity. Nanoparticles were fabricated via a desolvation method, and their surface was functionalized with folic acid to promote selective uptake by cancer cells overexpressing folate receptors. Morphological and dimensional analyses performed by atomic force microscopy (AFM), scanning electron microscopy (SEM), and fluorescence microscopy confirmed that all nanoparticles were below 100 nm and exhibited good colloidal stability. Voltametric measurements confirmed the successful incorporation of both rutin and folic acid within the (HSA-FA):Ru nanoparticle formulation. Biological evaluation was conducted on healthy L929 fibroblasts and HT-29 colon adenocarcinoma cells. MTS colorimetric assays revealed that (HSA-FA):Ru NPs significantly reduced the viability of HT-29 cells, while maintaining higher compatibility with L929 cells. Fluorescence and electron microscopy further confirmed preferential nanoparticle uptake and surface accumulation in HT-29 cells, supporting the role of folic acid in enhancing targeted delivery. The study demonstrates that HSA-based nanoparticles functionalized with FA and loaded with Ru offer a biocompatible and efficient strategy for selective intracellular drug delivery in colorectal cancer. These findings support the use of albumin-based nanocarriers in the development of targeted therapeutic platforms for cancer treatment.