No abstract

Photothermal therapy (PTT) is recognized as a promising approach for cancer theranostics via the nonradiative conversion of light into heat energy. PTT treatment is able to reduce the adverse side effects of traditional chemotherapy. Some nanomaterials functionalized with unique physical and chemical properties have been integrated with multiple imaging modalities and a therapeutic function for applications. In the past decade, various nanomaterials for PTT applications have been reviewed, but a comprehensive survey of all classes of photothermal nanomaterials developed in recent years has not been done. A comprehensive discussion of PTT mechanisms using different nanomaterials and their application in combination therapy is useful for providing insights for PTT material development for disease treatment in the future. In this review, the recent advancement of functionalized nanomaterials for PTT and the excellence of PTT combined therapies in the field of anticancer are discussed. The momentous property of nanomaterials tailored for advancing the noninvasive therapeutic approach of PTT is also highlighted. Because a great deal of PTT nanomaterials have been developed in the past decades and reviewed in recent years, in this review, we only include the latest results reported in the past 5 years for discussion and comparison.

A new RNA-selective fluorescent dye integrated with a thiazole orange and a p-(methylthio)styryl moiety shows better nucleolus RNA staining and imaging performance in live cells than the commercial stains. It also exhibits excellent photostability, cell tolerance, and counterstain compatibility with 4',6-diamidino-2-phenylindole for specific RNA-DNA colocalization in bioassays.

The universal fluorescent staining property of thiazole orange (TO) dye was adapted in order to be specific for G-quadruplex DNA structures, through the introduction of a styrene-like substituent at the ortho-position of the TO scaffold. This extraordinary outcome was determined from experimental studies and further explored through molecular docking studies. The molecular docking studies help understand how such a small substituent leads to remarkable fluorescent signal discrimination between G-quadruplex DNA and other types of nucleic acids. The results reveal that the modified dyes bind to the G-quadruplex or duplex DNA in a similar fashion as TO, but exhibit either enhanced or quenched fluorescent signal, which is determined by the spatial length and orientation of the substituent and has never been known. The new fluorescent dye modified with a p-(dimethylamino)styryl substituent offers 10-fold more selectivity toward telomeric G-quadruplexes than double-stranded DNA substrates. In addition, native PAGE experiments, FRET, CD analysis, and live cell imaging were also studied and demonstrated the potential applications of this class of thiazole-orange-based fluorescent probes in bioassays and cell imaging.