Seminar by Prof. Rainer Adelung

University of Kiel (Germany)

Exploring Physical Interactions: Novel Approaches for Antiviral and Antibacterial Treatments by Nanomaterials

This seminar talk will provide an overview of recent advancements in antiviral and antibacterial treatments for personal therapy and air filtration systems, focusing on the work of the functional nanomaterials group at Kiel University. Unlike traditional molecular drugs or medical agents, the primary emphasis here lies on physical interactions or interactions with nanostructured surfaces, rather than chemical effects influenced by drug solubility. The entire system, whether it's the complete environment of a technical system or the broader network surrounding personal therapy (including the immune system), is leveraged.

Two main examples will be discussed: tetrapodal microcrystals of zinc oxide and the graphene-based aeromaterials derived from them through a templating process. While the pharmaceutical effects of zinc oxide nanoparticles, which have long been used in various products like creams and ointments due to their mild antiseptic and drying properties, are well-known, tetrapodal zinc oxide has recently shown curative effects based on immunization [1] in animal models. This breakthrough discovery has led to the translation of tetrapodal zinc oxide from the research group to the pharmaceutical market, exemplified by the development of "Afinovir," a GMP-certified cream containing tetrapodal zinc oxide for herpes therapy (see Figure 1). Tetrapodal zinc oxide facilitates early virus detection by the immune system through the CD4 CD8 signaling pathway, enabled by antigen-presenting cells that can efficiently internalize the virus due to immobilization on nanostructured surfaces of the zinc oxide crystal.

Additionally, the talk will explore the antibacterial effects of tetrapodal zinc oxide, with a focus on their potential application in 3D printed skin patches. These patches demonstrate specific antibacterial effects and the ability to deliver proteins, such as VEGF, to aid in wound healing, as demonstrated by Leonard Siebert [2].

In contrast to personal therapeutic medicine, the sterilization effects provided by Aeromaterials in air filtration systems are less complex. The unique structural characteristics of Aeromaterials, including interconnected large free volumes and low weight, are utilized for the pyrolysis [3] of pathogens, as demonstrated by Fabian Schütt. The low mass results in low heat capacity, allowing for high temperatures to be reached with relatively low power consumption. The high free volume, combined with a hierarchical micro-nanostructure, ensures high filter efficiency. As part of the Graphene Spearhead Project AEROGrAFT, the development of an air filter system for passenger jets in collaboration with the aviation company Lufthansa Technik will be presented. This example will highlight the technological challenges and the certification procedures required in the aviation industry.

_{Figure 1. Micrographs of tetrapodal Zink Oxide. A. Scanning electron microscopy image, the arm diameters of the ZnO microcrystals are in the order of ~1-3µm SEM. B. Fluorescence microscopy of a tetrapod with GFP labeled herpes virus bound to a tetrapod.}

References

[1] The Journal of Immunology 196 (11), 4566-4575 (2016).
[2] Advanced Functional Materials 31 (22), 2170154 (2021).
[3] Materials Today 48, 7-17 (2021).