Table 3.

Parameters included in QSAR models.

Nanomaterial	Toxicity endpoint	Characterization	Reference
18 NMs (carbon-based, metal oxides)	Cytotoxicity, apoptosis, pro-inflammatory effects, haemolysis, viability, mitochondrial membrane potential, morphology	7 descriptors: size, surface area, morphology, metal content, reactivity, free radical generation, zeta potential	[107]
18 NMs	Viability	17 quantum mechanical descriptors (enthalpy of formation of nanocluster, total and electronic energy, core–core repulsion energy, solvent accessible surface, energy of the highest occupied molecular orbital, energy of the lowest unoccupied molecular orbital, gap between both, electronic chemical potential, valence band, conduction band, Mulliken’s electronegativity, Parr and Pople’s absolute hardness, Schüürmann Molecular Orbital shift alpha quantities, polarizability derived from the heat of formation, and polarizability derived from dipole moment) and 11 experimental descriptors (area, volume, surface diameter, volume/mass diameter, volume/surface diameter, aspect ratio, porosity, sphericity, circularity)	[111]
51 NMs with four metal core structures	Viability, reducing equivalents, apoptosis, mitochondrial membrane potential	5 descriptors: core composition, coating, surface modification, relaxivities, zeta potential	[112]
42 NMs with two cores	Cytotoxicity	6 descriptors: primary particle size, size in water, size in PBS, cell in cell culture medium, concentration, zeta potential	[113]
13 pure, core-shell and alloy Au/Pd TiO2 NMs	Cytotoxicity (CHO-K1 cells)	2 descriptors: size, surface area	[114]
9 metal oxide NMs	Cytotoxicity (BEAS-2B cells)	14 descriptors: atomization energy of the metal oxide, period of the NP metal, and NP primary size, in addition to NP volume fraction (in solution) were identified as most predictive	[115]
24 metal oxide NMs	ROS, oxidative stress, pulmonary inflammation in mice	30 theoretical descriptors: conduction band energy predictive for some, solubility for other metal oxide NPs	[116]
41 metal oxide NMs	Cytotoxicity	4 descriptors; size, electronegativity, polarizability, molar volume	[117]
17 metal oxide NMs	Cytotoxicity (HaCaT cells)	7 theoretical descriptors (number of metal atoms, number of oxygen atoms, molecular weight, charge of the metal cation corresponding to a given oxide, metal electronegativity, sum of metal electronegativity for the individual metal oxide, sum of metal electronegativity for the individual metal oxide divided by the number of oxygen atoms in a specific metal oxide)	[118]
24 metal oxide NMs	Viability, 2 cell lines	30 descriptors: conduction band energy and ionic index were identified as very predictive	[108]
44 iron oxide NMs	4 cell types, 4 assays	4 descriptors: primary size, spin–lattice, spin–spin relaxivities, zeta potential; no single parameter performed best	[109]
6 metal oxide NMs	Oxidative stress	1 descriptor: energy band structure	[119]
307 studies, Cd quantum dots	Viability	24 qualitative and quantitative features (ligand, shell, surface modification, assay type, exposure time, exposure concentration, cell anatomical type, cell origin)	[120]
20 C60 fullerene NPs	Mutagenicity	3 descriptors: dose, illumination, metabolic activation	[121]
84 f-MWCNTs	Cytotoxicity, protein binding, immune response	5 descriptors: zeta potential, electrophoretic mobility, surface area, porosity, solubility	[122]