Nanorobotics for Targeted Delivery

We have pioneered a general growth method to fabricate billions of designer nanostructures (Nat. Mat. 2013, [1]) that we termed nano- glancing angle deposition (nanoGLAD). The method allows us to realize billions of hybrid nanostructures with a material composition and control over the shape that cannot be obtained by other methods (see also Nanofabrication & Materials Discovery). Using nanoGLAD we grow nanopropellers with which we probe the microstructure of tissue. We also investigate nanocarrier-based gene delivery. An overview of our work can be seen in the Figure above.

We have used our nanoGLAD method over the years to grow magnetic nanopropellers that can be moved with great precision in solution using weak magnetic fields. We have previously shown their propulsion through very soft complex tissues such as mucous or the vitreous (Science Adv. 2018, [2]). One important aspect in developing the helical nanopropellers is to ensure that they can be biocompatible. We have shown that the strong hard magnetic FePt, which is biocompatible (Adv. Mat. 2020, [3]), can be integrated in the GLAD process. We have also realized structures that decompose in water by using an alloy from Mg and Zn as their body (Adv. Func. Mat. 2024, [4]). Moreover, tuning the Mg:Zn ratio allows us to tune the degradation time from hours to weeks.

In the course of our research, we have applied our magnetically actuatable nano- and microstructures to explore tissue penetration and found that the porosity of many biological barriers is poorly understood and difficult to measure. For this reason, we have expanded our research efforts and are establishing a setup to examine the microstructure of tissue. Our longstanding goal is the targeted delivery of genes that are too large for viruses to transport.

1. “Hybrid nanocolloids with programmed 3D-shape and material composition”, A.G. Mark, J.G. Gibbs, T.-C. Lee, P. Fischer, Nature Mat. 12, 802, (2013).
2. “A swarm of slippery micropropellers penetrates the vitreous body of the eye”, Z. Wu, J. Troll, H.-H. Jeong, Q. Wei, M. Stang, F. Ziemssen, Z. Wang, M. Dong, S. Schnichels, T. Qiu, P. Fischer, Science Advances 4, eaat4388, (2018).
3. “Biocompatible magnetic micro‐ and nanodevices: fabrication of FePt nanopropellers and cell transfection”, V.M. Kadiri, C. Bussi, A.W. Holle, K. Son, H. Kwon, G. Schütz, M.G. Gutierrez, P. Fischer, Adv. Mat. 32, 2001114 (2020).
4. “Degradable and Biocompatible Magnesium Zinc Structures for Nanomedicine: Magnetically Actuated Liposome Microcarriers with Tunable Release”, F Peter, VM Kadiri, R Goyal, J Hurst, S Schnichels, A Avital, M Sela, P Mora-Raimundo, A Schroeder, M Alarcón-Correa, P Fischer, Adv. Func. Mat., 2314265, (2024).