[Zurück]

C. Jochum, N. Adzić, G. Kahl, C. N. Likos:
"Modelling and conformation characteristics of DNA-based dendrimers";
Poster: From Electrons to Phase Transitions (ViCoM Conference 2018), Vienna; 04.04.2018 - 06.04.2018.

Dendrimers are synthetic macromolecules possessing a highly branched and regular
internal structure. They are synthesized in a step-wise fashion by repeating units from
various central multifunctional cores, on which radially branched shells called
generations are covalently attached. Charging these dendrimers leads to conformational
responsiveness, one of the most important ingredients for envisioned applications of the
same, which is essentially lacking for their neutral counterparts.
Recently, Dan Luo and co-workers at Cornell University synthesized dendrimer-like DNA
(DL-DNA) from the enzymatic ligation of Y-shaped DNA (Y-DNA) building blocks [1].
These charged DNA dendrimers are novel macromolecule aggregates, which hold high
promise in bringing about targeted self-assembly of soft-matter systems in the bulk and
at interfaces.
Inspired by these findings, we study systems of such DL-DNA molecules in order to
advance the theoretical analysis of novel self-assembled structures. First, we simulate a
single DL-DNA molecule, whose base-pairs are modeled by charged monomers. Their
interactions are chosen to mimic the equilibrium properties of DNA correctly. We then
employ MD simulations to measure the dependence of equilibrium properties, e.g. the
influence of salinity, the tensor of gyration, and form factors, on the dendrimer´s
generation.
The obtained results are compared to experiments. In the future, we plan to use DL-DNA
to investigate the phenomenon of cluster crystals in the bulk [2], a novel form of solids
with multiple site occupancy. Furthermore, we want to study two-dimensional surface
ordering of low-generation DL-DNA and Y-DNA with tunable rigidity around the junction
point [3].
The study of these charged dendrimer-systems is an important field of research in the
area of soft matter due to their potential role to various interdisciplinary applications [4,
5], ranging from molecular cages and carriers for drug and gene delivery in a living
organism to the development of dendrimer/dendron-based ultra-thin films (monolayers
and multilayers) in the area of nanotechnology.

[1] Y. Li, Y. Tseng, and D. Luo, Nat. Mater. 3, 38 (2004).
[2] B. Mladek, M. Neumann, G. Kahl, and C. Likos, Phys. Rev. Lett. 96, 045701 (2006).
[3] C. Velasco, C. Likos, and G. Kahl, Mol. Phys. 113, 2699-2706 (2015).
[4] D. Tully and J. Fréchet, Chem. Commun. 14, 1229 (2001).
[5] C. Lee, J. MacKay, J. Fréchet, and F. Szoka, Nat. Biotechnol. 23, 1517 (2005).

DL-DNA

Projektleitung Gerhard Kahl:
DFS