Table 2.

Designed targeted drug delivery systems based on nanomaterials or nanotechnology and their release characteristics.

Classification	Loaded drugs	Ligand	Target	Trigger	PTT	Reference
MSNs	DOX, ZOL	ZOL	Bone	pH		(Sun, Han, et al., 2016)
	PL, ZOL	ZOL	Bone	pH		(Qiao et al., 2017)
	ZOL, Au	ZOL	Bone		Yes	(Sun, Ge, et al., 2019)
Calcium phosphate NPs	MTX, ALN	ALN	Bone			(Chu et al., 2017)
Liposome	DOX	Asp8, folate	FR, bone			(Ke et al., 2017)
	ALN, DOX	ALN, hyaluronic acid	CD44, bone	Redox		(Feng et al., 2019)
nMOFs	ZOL	Folate	FR	pH		(Au et al., 2016)
Bioactive glass NPs	DOX			pH, NIR	Yes	(Xue et al., 2020)
Micelles	ALN, curcumin	ALN, Oligosaccharide of hyaluronan	CD44, bone	Redox		(Wang, Guo, et al., 2018)
	BTZ, ALN	ALN	Bone	pH		(Zhu et al., 2018)
	Docetaxel	Quinolone nonpeptide	IntegrinaVβ3			(Ross et al., 2017)
	DTX, ALN	ALN	Bone			(Liu, Romanova, et al., 2019)
QD	ALN, DOX	ALN	Bone	pH		(Li et al., 2017)
Tungsten bronze nanoparticles					Yes	(Jie et al., 2019)
Polymeric NP	DOX, ALN	ALN	Bone			(Rudnick-Glick et al., 2016)
	Cabazitaxel, ALN	ALN	Bone			(Gdowski et al., 2017)
	ZOL	ZOL	Bone			(Hatami et al., 2019)
	GANT58, ALN	ALN	Bone			(Vanderburgh et al., 2020)
	DOX, ALN	ALN, hyaluronic acid	Bone, CD44	pH, redox		(Zhao et al., 2017)
	GANT58			ROS		(Vanderburgh et al., 2019)
	PTX, ALN	ALN, folate	Bone, FR			(Chen et al., 2020)
	SN38, ALN	ALN	Bone	pH, NIR	Yes	(Wang, Huang, et al., 2018)
Dendrimer	Pt NPs	Carboxyl terminals	Bone		Yes	(Yan et al., 2019)
	BTZ	RGD	IntegrinaVβ3	pH		(Wang, Cai, et al., 2018)
	DTX, ALN	ALN, hyaluronic acid	Bone, CD44	pH, redox		(Bai et al., 2019)