Current strategies to enhance the targeting of polydopamine-based platforms for cancer therapeutics

Polydopamine (PDA), a dopamine-derived endogenous catecholamine polymer, has recently attracted considerable interest as photothermal reagent, particularly interesting in the application of multimodal synergistic cancer therapeutics. For surface-mediated drug delivery, PDA-based platforms exhibited excellent stability, biocompatibility and photothermal performance under the near infra-red (NIR) irradiation. Unfortunately, it was limited by concerns about non-selectivity, lower anticancer efficiency and potential cytotoxicity. Therefore, numbers of literatures have been reported on various modified PDA to improve targeting ability, reduce toxicity and combine with multiple treatment modes. Here, the purpose of this review is to summarise these contemporary PDA-based novel designs including physical, chemical as well as biological for potential strategies in the cancer target treatment according to their various stimuli-responsive properties, such as formulation types, pH, glutathione (GSH), peptides and receptors. In addition, we also discussed the structural properties and possible synthesis mechanisms of PDA in general which may provide an understanding of these current approaches and hope to explore the potential applications for future improvements about PDA.