Table 1.

Use of polydopamine in the treatment of head and neck cancer.

Reference	Nanotherapeutic System	Use of the Nanotherapeutic System	Use of Polydopamine	Results
Li et al., 2021 [57]	Polydopamine-modified black phosphorus nanosheets functionalized with polyacrylamide hydrochloride-dimethylmaleic acid (BP@PDA-PAH-DMMA).	pH-responsive charge reversal nanomedicine system for oral cancer.	Enhancing photothermal properties; improving stability.	Compared with the temperature change of bare BP NSs, the temperature of BP@PDA increased, which was connected to the good photothermal conversion efficiency of the PDA layer.
Maor et al., 2021 [61]	PLGA nanospheres encapsulating copper oxide nanoparticles (CuO-NPs) and coated with PEGylated polydopamine (CuO-NPs@L-PLGA/PDA/ PEG).	Laser-induced thermal response and controlled release of copper oxide nanoparticles from multifunctional polymeric nanocarriers in Cal-33 head and neck squamous cell carcinoma cells.	Photothermal therapy; surface modification.	Results showed that controlled release connected with high heating efficiency allows the designing of a thermal therapy approach, capable of killing tumor cells with lower laser power and shorter time, than in conventional therapies.
Zmerli et al., 2021 [42]	PEGylated PDA-based nanoplatform (PDA−PEG NPs).	As a nanoplatform with multifunctional properties including photothermal and photodynamic activities for esophageal cancer cell lines (KYSE-30).	Photothermal therapy; Photodynamic therapy; surface PEGylation.	They showed very low dark cytotoxicity in vitro, with a simultaneous high photothermal conversion efficiency, along with a higher photodynamic effect on cell lines using active targeting. It was possible to obtain a synergistic phototoxic effect after irradiation at two different wavelengths.
Jin et al., 2020 [73]	S-nitrosothiol functionalized polydopamine core and a gambogic acid-derivatized hyaluronic acid shell with doxorubicin (PDA–SNO–GA–HA–DOX).	For pH-induced chemotherapy, enzyme-triggered low-temperature photothermal therapy and NIR-dependent gas therapy for HN6 tongue squamous cell carcinoma treatment.	Photothermal therapy; Increasing biocompatibility, biodegradability; Enabling release of DOX in an acidic environment.	Studies have shown that nanocomplex achieved both tumor-specific chemotherapy and low-temperature photothermal therapy due to the use of polydopamine. In vivo studies from mouse models showed that the PSGHD nanocomplex can completely inhibit tumor growth and significantly extend the survival of tumor-bearing mice for 50 days.
Wang et al., 2018 [23]	PDA-coated gold–silver alloy NPs (Au–Ag@PDA NPs).	Mitochondria-targeted and exocytosis inhibition strategy of PDA-coated nanoparticles for enhanced papillary thyroid cancer therapy.	Photothermal therapy; surface modification.	Researchers investigated the endocytosis pathway, subcellular localization, and cellular responses between nanoparticles and TPC-1 cells. The results showed that the nanoparticles are hardly excreted by TPC-1 cells, leading to cell cycle arrest and survival pathway mediated by autophagy. With photothermal therapy, it was possible to obtain non-invasive thermal ablation.
He et al., 2017 [59]	Doxorubicin encapsulated in PLGA/polydopamine nanoparticle and functionalized with anti-EGFR antibody (DOX@PLGA/PD-C).	Photothermal and chemotherapy of UMSCC 22A head and neck cancer cells.	For photothermal properties and enabling surface modification.	Since the PLGA nanoparticle itself could not produce heat upon NIR irradiation, research showed that PLGA/PDA nanoparticle quickly heated the solution temperature to 45 °C, indicating that PLGA/PDA is a good photothermal converting material, preventing overheating or overburn situation. Because the nanoparticle was retained in the tumor tissue and only the sweat released its load inside the cancer cells, it was possible to minimize the cardiotoxicity associated with doxorubicin.
Zhang et al., 2017 [66]	Polydopamine and Poly-ethylenimine layers (PDA/PEI).	Modification of the surface of esophageal stents through the PDA/PEI layer to give them an anti-cancer effect.	For PDA good binding properties, allowing to bind imino groups of PEI via Michael addition and Schiff base reactions.	PDA/PEI layers showed remarkable improvement in esophageal cell apoptosis and necrosis, suggesting excellent anti-cancer function.