Hyperbranched DNA clusters

TL;DR

This study combines simulations and experiments to explore the formation of hyperbranched DNA clusters, revealing deviations from classical theory due to intracluster bonds and proposing an extended theoretical model.

Contribution

It introduces an extended Flory-Stockmayer theory that accurately describes DNA cluster formation considering intracluster bonds, validated by simulations and experiments.

Findings

Clusters do not reach percolation despite full bonding due to intracluster bonds.

The extended theory matches experimental and simulation data.

DNA nanostars form hyperbranched structures with tunable properties.

Abstract

Taking advantage of the base-pairing specificity and tunability of DNA interactions, we investigate the spontaneous formation of hyperbranched clusters starting from purposely designed DNA tetravalent nanostar monomers, encoding in their four sticky-ends the desired binding rules. Specifically, we combine molecular dynamics simulations and Dynamic Light Scattering experiments to follow the aggregation process of the DNA nanostars at different concentrations and temperatures. At odd with the Flory-Stockmayer predictions, we find that, even when all possible bonds are formed, the system does not reach percolation due to the presence of intracluster bonds. We present an extension of the Flory-Stockmayer theory that properly describes the numerical and the experimental results.