Elucidation the binding interaction of hypericin-loaded P84 copolymeric micelles by using 1D and 2D NMR techniques

Hypericin (HYP) is an active compound of Hypericum perforatum. Associated with photodynamic therapy (PDT), HYP has shown a broad therapeutic potential against microorganisms and cancer cells. Due to the low water solubility of HYP, its application in the biological medium becomes limited. To solve this limitation, our research group has been used copolymeric micelles to carrier HYP with high efficiency. However, there is no elucidated mechanism for HYP delivery mediated by copolymeric micelles. In this sense, we believed that the study of binding-sites of copolymeric micelles and HYP is the first step to its understanding. For this purpose, in this work, we employed 1D and 2D NMR techniques to investigate the behaviour of HYP-loaded P84 micelles in different concentrations . 1D and 2D NMR analysis revealed that HYP molecules were arrangement in a π-stacked aggregation form with a specific location on the core of P84 micelles.