Investigating Non-Covalent Interactions of Human Serum Albumin with Doxorubicin and Folic Acid

The development of effective delivery systems for antitumor drugs with increased specificity and controlled release is one of the challenges for biomedical chemistry. This paper presents studies of non-covalent interactions of human serum albumin, which may be a promising carrier for drug delivery, with antitumor antibiotic doxorubicin and folic acid, which have the potential of a guide ligand. Intermolecular interactions of doxorubicin and folic acid with human serum albumin were studied by spectroscopic methods at various pH levels and temperatures. The binding strength of doxorubicin and folic acid responded differently to pH changes. The affinity of the drug to protein increased with the transition from acidic to alkaline conditions, while pH 7.4 was optimal for binding for folic acid. In the case of the triple system, it was found that there was no significant effect of albumin complexation with folic acid on non-covalent interaction with doxorubicin. As expected, binding to these active compounds altered the conformation of the protein. At the same time, this change was minimal in physiological pH for folic acid and in alkaline for doxorubicin. Additionally, the therapeutic properties of doxorubicin, non-covalently bound to human serum albumin, were shown to be preserved in vitro.