Lyotropic liquid crystals (LCs) seem to play a significant role in biological systems. The well-known example of this material is DNA, that tends to self-organize into various lyotropic mesophases at high concentration water solutions [1]. Previous studies indicated that gold nanoparticles show different arrangement in DNA LCs. It was observed that elongated nanoparticles accumulate in the whole volume of the mesophase, while nanoclusters tend to aggregate on the top of the mesophase [2-3].

In the present work, mini gold nanorods (GNRs) have been chosen due to their strong photothermal efficiency [4]. The formation of DNA LCs doped with mini GNRs was investigated and compared with pure DNA LCs by polarized light microscopy. Furthermore, two-photon microscopy was used to image the distribution of mini GNRs in the DNA LC matrix. These systems could potentially be useful as models of interactions of NRs with DNA for biomedical applications such as cancer thermotherapy, owing to the large absorption cross-sections of mini GNRs. Moreover, mini GNRs exhibit higher cellular uptake (especially in tumor changed tissues) and lower cytotoxicity both in vitro and in vivo [5]. Reliable and reproducible protocols describing the synthesis of mini GNRs with well-defined plasmonic and optical properties predestine them as model materials for such investigations.

References

[1] Phys. Rev. Lett., 2006, 96, 177801

[2] Nanoscale, 2013, 5, 10975

[3] Langmuir, 2017, 33, 36, 8993–8999

[4] Chem. Mater., 2018, 30, 4, 1427–1435

[5] ACS Biomater. Sci. Eng., 2016, 2, 5, 789 –797