The massive production and application of nanomaterials
(NMs) have
raised concerns about the potential adverse effects of NMs on human
health and the environment. Evaluating the adverse effects of NMs
by laboratory methods is expensive, time-consuming, and often fails
to keep pace with the invention of new materials. Therefore, in silico methods that utilize machine learning techniques
to predict the toxicity potentials of NMs are a promising alternative
approach if regulatory confidence in them can be enhanced. Previous
reviews and regulatory OECD guidance documents have discussed in detail
how to build an in silico predictive model for NMs.
Nevertheless, there is still room for improvement in addressing the
ways to enhance the model representativeness and performance from
different angles, such as data set curation, descriptor selection,
task type (classification/regression), algorithm choice, and model
evaluation (internal and external validation, applicability domain,
and mechanistic interpretation, which is key to ensuring stakeholder
confidence). This review explores how to build better predictive models;
the current state of the art is analyzed via a statistical evaluation
of literature, while the challenges faced and future perspectives
are summarized. Moreover, a recommended workflow and best practices
are provided to help in developing more predictive, reliable, and
interpretable models that can assist risk assessment as well as safe-by-design
development of NMs.