Tuning and modeling nanoparticles with flexible cores

Nanoparticles are versatile platforms functionalized with ligands on their surfaces. Their diverse applications span cosmetics, material engineering, and biomedicine. Coarse-grained modeling is typically employed for understanding nanoparticle properties and design, but it often represents the core as rigid, limiting the portrayal of environmental and biological interactions.

To capture the full range of nanoparticle dynamics, Paesani and Ilie developed a tunable and responsive coarse-grained model involving what they call MetaParticles (MPs) — nanomaterials with flexible cores. In simulations, they subjected MPs of various sizes and symmetries to external stress.

“The MP model stands out due to its modularity,” said author Ioana Ilie. “By adjusting the springs, representing flexible bonds, that connect beads mimicking nanostructures, the model can be tuned to become either more flexible or more rigid; by endowing the beads with attractive properties, the surface becomes heterogeneous; by adjusting bead arrangement, the MPs become anisotropic, enabling the study of phenomena such as aggregation, cellular uptake or material behavior.”

The duo’s results demonstrated elastomer-like responses of MPs under applied tension, with variations depending on size, bead arrangements, and area of applied stress. Additionally, they found that MPs follow different deformation pathways based on size, which further contributes to the development of tunable nanomaterials.

The authors aim to eventually enhance the adaptability of nanoparticles in biomedical applications, where core design is tightly linked to precise functions such as drug delivery and imaging.

“We are now enriching the MP model with specific details gained from atomistic simulations and experiments performed by our collaborators,” Ilie said. “Based on the gained knowledge, we will fine-tune the model to mirror interactions of flexible nanoparticles and understand their interactions with the cellular membrane.”

Source: “Metaparticles: Computationally engineered nanomaterials with tunable and responsive properties,” by Massimiliano Paesani and Ioana M. Ilie, Journal of Chemical Physics (2024). The article can be accessed at https://doi.org/10.1063/5.0232274 .

This paper is part of the 2024 JCP Emerging Investigators Special Collection, learn more here .