Synthesis, characterization, and biological applications of semiconducting polythiophene‐based nanoparticles

In recent years, polythiophene-based nanoparticles (PT-NPs) have attracted increasing attention because of their outstanding characteristics deriving from a wealth of properties such as charge conduction in the oxidized/reduced states, light absorption/emission at an appropriate wavelength, geometrical adaptability, thermal and chemical stability, and solubility in common solvents. Furthermore, the great synthetic flexibility of the thiophene core has allowed the engineering of a multitude of nanomaterials with made-to-order properties. This review is focused on the synthesis and characterization of aqueous PT-NPs and their biological applications. In particular, both in vitro and in vivo bioapplications will be presented, in which thiophene-based nanomaterials act as photoactuators, that is, as exogenous components capable of transforming a primary stimulus of light into a highly spatiotemporally resolved secondary stimulus able to alter cell's physiological functions. Furthermore, examples of applications of PT-NPs in biomedicine, such as photodynamic therapy and photothermal therapy, will be discussed.