Photothermal and
photodynamic therapies (PTT/
PDT) have been widely accepted as noninvasive therapeutic methods for
cancer treatment. However, tumor hypoxia and insufficient delivery of photoactive compounds to
cancer cells can reduce the efficacy of
phototherapy. Herein, we first synthesized thiolated
hyaluronic acid (THA) and then conjugated it with
catalase (CAT) onto
chlorin e6 (Ce6)-adsorbed small
gold nanorods (Ce6@sAuNRs) with near-infrared (NIR)/visible light activated photothermal/photodynamic effects. The conjugation of THA and CAT on Ce6@sAuNRs resulted in a red-shift of the longitudinal LSPR absorption band of sAuNRs up to 1000 nm and maintained the excellent enzymatic activity of
catalase. Modification of Ce6@sAuNRs with THA resulted in efficient internalization of the nanocomposite into MCF-7/ADR multidrug-resistant (MDR)
breast cancer cells (CD44+), thereby significantly enhancing the intracellular accumulation of the
photosensitizer Ce6. CAT endows Ce6@sAuNRs with self-supporting
oxygen production, which enables them to efficiently generate
singlet oxygen (1O2) under 660 nm
laser irradiation and enhances the photodynamic effect against hypoxic
breast cancer cells. The results highlight the prospect of this novel multi-functional nanoplatform integrating active
biological macromolecules (THA and CAT) into
photosensitizer/photothermal
gold nanocomposites in overcoming the limitations of hypoxic MDR
breast cancer cell treatment.