Table 2.

Metal oxide nanoparticles used in anti-cancer therapies.

Material	Nanoparticles Parameters	Nanoparticles Functions	Ref.
Bi2O3	Spherical shape, 35 nm	Combination with photodytase for targetable phototherapy	[183]
Bi2O3	Spherical particles, 97 nm	Examined dose-dependent cytotoxicity and 23 apoptosis response of Bi2O3 NPs in human breast cancer (MCF-7) cells	[184]
Bi2O3	43 nm-α-B2iO3, 37 nm-α-Bi2O3 -APTMS (3-aminopropyl)trimethoxysilane	Theranostic system (diagnosis and treatment in one)	[80]
Bi2O3	Bi2O3 with hyaluronic acid, quasi-spherical shape, 45 ± 0.6 nm	Targeted computed tomography imaging and tumour radiosensitization	[79]
CeO2	15–20 nm	Cytotoxic effect against colorectal cancer cell line	[169]
CeO2	Band-gap was 4.1 eV, spherical shape, 15–20 nm	Cytotoxic effect against colorectal cancer cell line	[170]
CeO2	Calculated crystallites from Scherrer around 4 nm	Sensitization to radiotherapy	[185]
CeO2	Spherical particles, 100–200 nm	Cytotoxic effect on prostate cancer cells	[186]
CuO	Spherical particles average 5.4 nm	Sensibiliser for radiation therapy	[187]
CuO	Nanoparticles can be seen in TEM images, but the measured diameter was about 1–2 μm	Antitumour activity on human colorectal cancer cell lines	[188]
CuO	10 to 190 nm average 110 nm	Photothermal activity against lung cancer	[174]
Fe3O4-DOX	~22 nm, spherical, Au-Fe3O4, DOX	Magnetic gold nanoparticles modified with iron oxide nanoparticles and functionalized with PEG for transporting the anti-cancer drug DOX	[189]
Gd2O3	3–4 nm	MRI imaging	[178]
Gd2O3	Average size 1.8 nm	Electron capture anti-cancer therapy	[190]
Gd2O3	100 nm	Magnetic imaging and theranostics	[177]
GaO(OH)	Oval GaO(OH) with β-cyclodextrin NPs, 380–400 nm	A drug carrier	[159]
HfO2	65 nm	Anti-cancer effects Enhancing the effects of radiation therapy	[191]
SnO2	Irregular NPs, 21.3 ± 11.4 nm	Cytotoxicity, ROS and H2O2 generation along with lipid peroxidation, SnO2 NPs weakened the antioxidant capacity of cells	[192]
SnO2	Folic acid coated tin oxide nanoparticles (FA-SnO2 NPs), Spherical NPs, 157 nm,	Targeting human ovarian cancer cells with minimal side effects against normal cells	[2]
TiO2	TiO2 -PEG Spherical particles, 10–25 nm,	Energy conversion to enhance induced heat efficacy in photo-thermal therapy; reduction of melanoma tumour size after PTT	[193]
ZnO	Spherical and hexagonal NPs, 45–60 nm	Antioxidant and cytotoxic properties in lung cancer (A549) cells	[166]
ZnO	Approximately 20 nm	Cytotoxic properties against human ovarian cancer cells	[158]
ZnO	Nanoparticles can be seen in TEM images, but the measured hydrodynamic diameter came out to 13.87 nm	Anti-cancer agents	[167]
ZnO	Marsdenia Tenacissima hexagonal, elongated and rod-like ZnO at different nanometre scales	Anti-cancer agent	[168]