Quasi-SMILES-Based Nano-Quantitative Structure–Activity Relationship Model to Predict the Cytotoxicity of Multiwalled Carbon Nanotubes to Human Lung Cells

Quantitative structure–activity
relationship (QSAR) models
for nanomaterials (nano-QSAR) were developed to predict the cytotoxicity
of 20 different types of multiwalled carbon nanotubes (MWCNTs) to
human lung cells by using quasi-SMILES. The optimal descriptors, recorded
as quasi-SMILES, were encoded to represent the physicochemical properties
and experimental conditions for the MWCNTs from 276 data records collected
from previously published studies. The quasi-SMILES used to build
the optimal descriptors were (i) diameter, (ii) length, (iii) surface
area, (iv) in vitro toxicity assay, (v) cell line, (vi) exposure time,
and (vii) dose. The model calculations were performed by using the
Monte Carlo method and computed with CORAL software (www.insilico.eu/coral).
The quasi-SMILES-based nano-QSAR model provided satisfactory statistical
results (R2 for internal validation data
sets: 0.60–0.80; R2pred for external validation data sets: 0.81–0.88). The model
showed potential for use in the estimation of human lung cell viability
after exposure to MWCNTs with the following properties: diameter,
12–74 nm; length, 0.19–20.25 μm; surface area,
11.3–380.0 m2/g; and dose, 0–200 ppm.