Materials-Biology Interactions - A Huge Challenge for Nanotechnological Applications

The interaction of man-made materials with biological systems - e.g. cells, tissues organs - is an important issue, especially for products in the fields of medicine, food, cosmetics and other consumer products.

The new possibilities offered by nanotechnology will, most likely, lead to an increase in contact with living systems. New products and applications will interact with the surrounding tissue in two ways: They will bring about the desired effect(s) of e.g. medical applications such as bone replacements or artificial heart valves; they might, however, also exert an unwanted - i.e., negative - impact, e.g. through unintended ingestion or inhalation of nanomaterials.

The consequences of these "side effects" must be studied in detail as we have to know how to handle nanomaterials in their specific applications. To provide answers on questions such as the stability of nanomaterials within the human body, the chances of exposure during the use of "nano-products" or the biological mechanisms that may be induced by nanoparticles or nanomaterials to the general public and to the various stakeholders involved is a key requirement if the research community is to introduce nanotechnology in a responsible manner.

In our laboratory, we try to provide answers to these issues by focusing on three different topics:

• The basic mechanisms of cellular responses to new materials - CellBio@Interfaces
• The use of new materials for medical applications - MaTisMed
• The possible risks through interactions of nanoparticles with human cells and tissues - Nanointercell

The first topic comprises the development of cellular systems and monitoring tools for the characterisation of cell-material interactions. We thus study the behaviour, status and health of thousands or millions of cells in culture systems. A more precise understanding of minute differences between individual cells or cell types could lead to better treatments for diseases and a more predictable design for cell-based sensors as well as for tissue engineering scaffolds.

The second topic is to define and refine materials and material surfaces in such a way that cell migration, proliferation and differentiation can be controlled according to the final function an implant has to fulfil.

For this purpose, we try to model the in vivo situation as closely as possible using cell lines and primary cells of different species, preferentially human cells. These models are being used to investigate how chemical composition, structure, the release of bioactive substances and applied forces at the cell-material interface influence cellular performance.

Thirdly, we are interested in the impact of nanomaterials on living systems, as several engineered nanomaterials (ENMs) such as carbon nanotubes (CNT), metal oxides or metal nanoparticles are already produced on an industrial scale and used in a huge variety of products.

Their potential impact on health and environment is still controversial. Yet, it is still unknown to what extent ENMs are able to adversely affect biological processes. With our activities, most of which are embedded in and coordinated with a world-wide network of experts, we want to actively contribute to a safe and sustainable development of nanotechnology.

The open questions in relation to nanoparticles and their possible risks are many. One of the most important challenges is the dependency of biological effects on the properties of the nanoparticles in question, especially their size, surface properties and chemical composition.

Moreover, biological effects may vary tremendously depending on the different uptake routes (lung, gut, skin), or tissues and organ systems such as the immune system, neurons, macrophages or the liver may exhibit completely different reactions in response to nanomaterial X, Y or Z.

The complexity of this field makes it very difficult to focus on all these questions simultaneously. The only way of tackling these issues is through an "integrated approach", an international network of research groups and institutes that complement each other, exchange data and results and, eventually, assemble the separate pieces of the puzzle into a coherent framework of knowledge and expertise.

We are, therefore, actively engaged in the following expert groups and international consortia:

• Academic member and member of the steering committee of the DECHEMA Working Group "Responsible Production and Use of Nanomaterials"
• Member of the Council of the European Academy for the Research on the Consequences of Scientific and Technological Advance; Project Group: Nanomaterials, Nanodevices, Nanocomputing
• Appointed as "Nanobotschafter (Nano ambassador)", an initiative of the "Deutsches Museum" in Munich
• Manager of the "NanoCare" consortium, a research project of the German Ministry for Education and Research
• Member of the Action Group "NanoDialog" of the German Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (BMU)
• Founder member of the IANH, the "International Alliance for NanoEHS Harmonization"
• Elected member of the foundation board of the "GEN SUISSE" foundation
• Member of the scientific board of the CNT-Initiative, an activity of the German Industry funded by the German Ministry for Education and Research

Further Projects

NanoImpactNet: FP7 network (not a research project) that will

• Facilitate collaboration between projects
• Communicate results to stakeholders and their needs back to researchers
• Help implement the EU's Action Plan for Nanotechnology

NanoMMUNE: FP7 research project that will

• the synthesis and detailed characterization of representative classes of ENs.
• the monitoring of potential hazardous effects by in vitro and in vivo systems.
• transcriptomics and oxidative lipidomics to determine nanotoxic signatures.
• risk assessment of potential adverse effects of ENs on human health.

DaNa: a German initiative together with Switzerland and Austria on the

• Acquisition, evaluation and broad-based illustration of societal relevant data and findings of nanomaterials