Cells at Surfaces

The cells at surfaces group aims to understand the mechanisms of how human cells and tissues interact with materials/material surfaces and to use this knowledge for the development of novel materials for Healthcare applications.

Using novel advanced in vitro models that more closely mimic the in vivo situation; we study the cellular events governing integration or non-integration of materials into host tissue as well as cellular processes involved in wound healing. We are also interested in how drug-releasing materials can be used to steer the tissue response.

Improving wound healing

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Fig.1 Scanning Electron Microscopy (SEM) image of a macrophage embedded in a fibrin-gel
When damage to the body occurs, healing processes often lead to fibrosis or tissue scarring, where normal tissue is replaced by permanent scar/fibrotic tissue with impaired functionality. This development of fibrotic tissue is commonly observed in response to implantation of materials.

Our goal is to understand the occurrence of and mechanisms involved in impaired wound healing, tissue scarring as well as fibrosis induced by the implantation of biomaterials for the development of material-based treatment strategies. For this, we develop new in vitro models including co-cultures and 3D-cultures and use analytical tools including Microarray-technology, ELISAs, SEM or 2-photon microscopy.

Steering integration and non-integration of materials

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Fig.2 Confocal Laser Scanning Microscopy (CLSM) image of human bone cells (actin cytoskeleton in green, nucleus in blue) on blood-derived fibrin (red) formed on mi-cro-rough titanium after 4 days of culture.
Implantable biomaterials are designed to function either in a transient or permanent manner. Depending on the clinical indication, integration of an implant material into the host tissue is desired or needs to be avoided. Generally, fast and specific protein adsorption and enhanced cell migration towards the implant is beneficial in the former situation, whereas non-fouling is favored in the latter one.  In both cases however, implant surface properties including roughness, surface chemistry or wettability influence the tissue response to the material. Addition of drug-release functionality to a material can be used to further enhance such a response or to add novel properties such as an antibacterial effect to the material.

Our aim is to understand how such material properties influence different stages of the tissue response to implants and to develop novel materials and material surfaces to either achieve or to avoid tissue integration.

Our tool box

We study cell-material interactions as well as the early events of blood-material interaction and its influence on human cell response by developing tissue-specific in vitro models mainly focusing on bone, skin and soft tissue. Ultimately, we evaluate the predictive power of our models via correlation with in vivo results and clinical data. For this, we use state of the art techniques including gene- and protein expression analysis, siRNA or fluorescence microscopy.