Table 2.

Summary of advantages of PDA core@shell nanoparticles with various cores.

Types of the core	Representative nanoparticles	Advantages of PDA modification	Ref.
Metal core	Au@PDA	Direct the growth of Au nanopetals Surface passivation Photothermal stability Improve the biocompatibility	[41,45,46]
	Fe2O3@PDA Fe3O4@PDA	Anchor bioactive molecules Secondary modification Photothermal conversion	[52,53]
	TiO2 NT@PDA	Improve the biocompatibility Enhance drug loading efficiency	[59,60]
	Mn3O4@PDA MnCO3@PDA	Improve the relaxation rate Enhance drug loading efficiency	[[62], [63], [64], [65]]
	ZnO@PDA	Improve the biocompatibility	[67,68]
Nonmetal core	MSN@PDA	pH-responsive “gate keeper”	[42,72,73]
	RGO@PDA	Improve conductivity Enhance bioactivity	[44,78]
	HAp@PDA	Improve biocompatibility Enhance bioactivity	[81,82]
Organic core	PLGA@PDA	Improve biocompatibility Enhance hydrophilicity	[83]
	BSA@PDA	Enhance drug loading efficiency	[94]
MOF core	MIL-100@PDA ZIF-8@PDA	Improve the biocompatibility Tune the biodegradability	[[88], [89], [90]]
Drug self-assembly core	DOX@PDA PTX@Au@PDA/DOX TIIA@PDA	Prolong the blood circulation time pH-responsive “gate keeper”	[[91], [92], [93]]