An albumin structure-dependent fluorescent probe for cell imaging and chemo-photodynamic therapy: an in vitro evaluation

Abstract

A protein structure-dependent probe (OTB) for human serum albumin (HSA) was designed. Molecular simulation were used to assist probe design. OTB exhibited favorable selective HSA sensitivity and strong HSA binding ability. As a cationic molecule, OTB could form a stable amphipathic complex with water-soluble pillar [5]arene (WP5). More interestingly, the WP5-OTB complex possessed better HSA responsiveness and stronger HSA binding ability than OTB. The detection limit (3σ/k) of WP5-OTB towards HSA was determined to be 0.33 μM. WP5-OTB complex possessed excellent anti-interference ability in the selective recognition of HSA. Common commercial drugs, fluorescent amino acids, and fatty acids had almost negligible effect on the HSA responsiveness of the complex. The WP5-OTB complex self-assembled into supramolecular fluorescent probe in aqueous solution, and the supramolecular probe possessed favorable HSA-induced bioimaging property, pH-sensitive drug delivery property, and photodynamic activity.