Assembly of multifunction dyes and heat shock protein 90 inhibitor coupled to bovine serum albumin in nanoparticles for multimodal photodynamic/photothermal/chemo-therapy.

The proangiogenic protein, survivin, is a client protein for heat shock protein 90 (Hsp-90), whose overexpression is induced by photodynamic therapy (PDT), leading to the inhibition of capase-9 and the blockage of apoptosis. The overexpression of Hsp-90 in cancer cells can rapidly acquire thermoresistance during photothermal therapy (PTT), leading to insufficient apoptosis, increased cell viability, and tumor recurrence. A potential approach to block the PTT-induced overexpression of Hsp-90 and the overexpression of survivin is developed by using an Hsp-90 inhibitor and anticancer agent, namely, geldanamycin (GM). These inhibitors also develop a mild-temperature PTT strategy to reach synergistic PDT and PTT efficiency. Thus, Cy7-SQ is designed by a covalent disulfide linkage between a photothermal agent (i.e., canine dye 7 [Cy7]) and a photosensitizer (i.e., squaraine dye [SQ]) for the improved photostability and thermal stability of Cy7 and SQ. The cleavage of the Cy7-SQ linkage by glutathione in a tumor microenvironment increases the efficiency of synergistic PDT and PTT. In the current study, bovine serum albumin (BSA)/Cy7-SQ/GM nanoparticles are developed through the self-assembly of BSA, Cy7-SQ, and GM to accelerate the apoptosis of cancer cells via near-infrared (NIR) laser irradiation, thus realizing Hsp-90-regulated synergistic PDT/PTT combined with chemotherapy.

Highly Sensitive and Selective Determination of Tertiary Butylhydroquinone in Edible Oils by Competitive Reaction Induced "On-Off-On" Fluorescent Switch.

As one of most common synthetic phenolic antioxidants, tertiary butylhydroquinone (TBHQ) has received increasing attention due to the potential risk for liver damage and carcinogenesis. Herein, a simple and rapid fluorescent switchable methodology was developed for highly selective and sensitive determination of TBHQ by utilizing the competitive interaction between the photoinduced electron transfer (PET) effect of carbon dots (CDs)/Fe(III) ions and the complexation reaction of TBHQ/Fe(III) ions. This novel fluorescent switchable sensing platform allows determining TBHQ in a wider range from 0.5 to 80 µg mL(-1) with a low detection limit of 0.01 µg mL(-1). Furthermore, high specificity and good accuracy with recoveries ranging from 94.29 to 105.82% in spiked edible oil samples are obtained with the present method, confirming its applicability for the trace detection of TBHQ in a complex food matrix. Thus, the present method provides a novel and effective fluorescent approach for rapid and specific screening of TBHQ in common products, which is beneficial for monitoring and reducing the risk of TBHQ overuse during food storage.