The research group of Prof. Plank focuses on developing tools and technologies for targeted delivery of active substances and uses such tools for therapeutic purposes. In this context, a major focus has been the construction of virus-like particles for nucleic acid delivery. Synthetic modules representing essential viral functions are self-assembled to form nanoparticles with virus-like biological function.

Equipping these delivery systems with magnetic nanoparticles allows remote-controlling and localizing delivery by magnetic force. “Magnetofection”, invented by Prof. Plank and Christian Bergemann, greatly improves dose-response profiles and delivery kinetics, briefly the efficiency, of most gene vectors and is therefore used by many researchers worldwide. The Plank group and collaborators have used Magnetofection with great success in a veterinary clinical study of immuno gene therapy of feline fibrosarcoma. A platform technology for combined magnetic cell separation and Magnetofection cells has been developed in the EU-Project Magselectofection. And in the EU funded project GAMBA, magnetic nanoparticles have served as actuators for activating heat-responsive promoters for controlling gene expression via AC magnetic field hyperthermia.

An extension of the magnetic drug targeting concept is its combination with ultrasound-triggered delivery. For this purpose, the Plank group develops magnetic microbubbles. These are gas-filled spheres that comprise in their shells the active agent to be delivered and a multitude of magnetic nanoparticles. Microbubbles are responsive to ultrasound, that is, ultrasound can be used to image drug delivery and to destroy microbubbles. Hence, magnetic microbubbles can be accumulated at a target site by magnetic force, and local drug release can be triggered by ultrasound irradiation.

Magnetic formulations and microbubbles can be used for medical imaging. Magnetic nanoparticles and their formulations are suitable contrast agents in magnetic resonance imaging, microbubbles can be used in ultrasound diagnostics. This work is done in collaboration with the Departments of Nuclear Medicine and Radiology at our university hospital.

Last but not least, Prof. Plank’s research group is also engaged in biomaterials science and tissue engineering. Implant materials such as titanium and steal devices (e.g. screws, plates, stents) or collagen or fibrinogen are modified with synthetic nucleic acid vectors. Cells that colonize such implants get transiently programmed to produce desired growth factors that induce a desired cell differentiation process. The research group focusses on bone and cartilage healing. Fields of application will be plastic and orthopedic surgery as well as dental medicine.

In all these projects, the chemistry of biologically functional molecules, their biophysics and the biological activity resulting from chemical structure and physical properties are decisive factors. Concerning methods, our work comprises everything from chemical synthesis (peptide and polymer chemistry, synthesis of magnetic nanoparticles), to biophysical characterization, to exploiting self-assembly in pharmaceutical formulation, to application in cell culture and animal models including the relevant biological and biochemical characterization techniques.

It is intended to forward this work into human clinical application within the coming years. Therefore, Prof. Plank has founded the spin-off company Ethris GmbH (www.ethris.com) together with Dr. Carsten Rudolph. The founders serve as managing directors of the company. Ethris develops messenger RNA therapeutics based on the academic discoveries of the founders and their coworkers.