Non-conjugated polymers with intrinsic luminescence for drug delivery

Luminescence plays an important role in advancing various research fronts. Traditionally, luminescence from polymeric luminogens is attributed to the presence of conjugated structures. In recent years, efforts have, however, been directed to deciphering the photophysics of polymeric luminogens in which conjugated structures are absent. These non-conjugated polymers do not experience aggregation-caused quenching as the conventional ones do. Instead, they display aggregation induced emission (AIE)-like properties. Because many dosage forms and carrier types (including tablets, microgels, nanoparticles, and films) exist in a highly aggregated state or solid state, non-conjugated polymeric luminogens exhibit potential for use in drug delivery. The objectives of this article are to highlight the practical potential of these luminogens as intrinsically luminescent carriers for drug delivery, and to revisit the opportunities and challenges of using them in theranostics.