Nano Korea is the largest international symposium on the nanoscale science and technology in the country. The 2022 edition, the 20th International Nanotech Symposium & Exhibition, which was held in Ilsan, South Korea, on 6-7 July 2022, was a meaningful occasion to confirm major research results and up-to-date research trends in Korea and overseas, increase exchanges among researchers in relevant fields, and materialize the results of research. The conference was well visited, attracting more than 1.500 international participants from academia, industry and regulators.

SABYDOMA’s partner KRICT (Dr Jongwoon Kim and Ms. Minju Na) represented the project in the international conference. Under the title “Development of a nano-mixture QSAR model for predicting the toxicity of metal oxide mixtures to Vibrio fischeri”, Minju presented a poster on her research study which conducted both mixture toxicity assay and molecular dynamics (MD) based molecular descriptor calculations to develop a nano-mixture QSAR model. The mixture toxicity assay was performed with SiO2, TiO2, and ZnO nanoparticles (NP) of various sizes (8 ~ 140 nm). Molecular descriptors were calculated based on MD to reflect the characteristics of each NPs of different sizes. Two machine learning algorithms (random forest (RF), support vector machine (SVM)) were applied to develop a nano-mixture QSAR model. A total of two types of models (experiment-based and calculation-based) showed good performance with R2 > 0.7. The RF based model had a slightly higher performance than the SVM based model.

The fact that Metal oxide (MO) nanoparticles (NPs), which are widely used in various applications, have size-dependent unique physicochemical properties, means that toxicity can occur among chemicals at no-observed effect levels by the cocktail effect. As the nano-mixture toxicity is one of hot issues in the fields of toxicology and environmental science from the aspects of both sides on risk assessment and safe-by-design of mixture products, this work was very relevant for the conference.

Minju explaining her work to one of the participants of the conference