Studies of Cell Adhesion and Cell Differentiation by Micro-and Nanostructured Surfaces

Background: Tissue engineering is an interdisciplinary research field with the goal to manufacture in vitro tissues and organs; so far, this succeeds only in few 3D tissues. Culturing primary cells is challenging since most human cells are fully differentiated in the adult and can, therefore, be poorly proliferated in vitro. Also, a loss of function and apoptosis can be induced during isolation and cultivation. Alternative cell sources are adult stem cells, as they show a high potential for proliferation and differentiation. For effective isolation of adult stem cells biocompatible and micro-and nanostructured cell culture systems are required. Fundamental investigations of the quality of material and methods for the potential production of functionalised surfaces have been done. Further, the biocompatibility and adhesion behaviour of defined epidermal cells on these modified surfaces have been evaluated. Methods: Cells were isolated from human skin material. The adhesion and differentiation of these primary epidermal cells on various surfaces were evaluated. Basically polymer surfaces, which differ in their properties, were investigated. Additionally, some polymer surfaces were gradually modified with functional groups, e.g. carboxylic groups and/or chemical or biochemical spacer molecules such as Protein G'. The application of the functional groups and/or chemical or biochemical spacer molecules could be confirmed with chemical and physical methods such as testing of hydrophobicity, ninhydrin test, measurements with a fluorescence-scanner and surface analysis through X-ray photo-electron spectroscopy (XPS). Results: Distinctive behaviour in adhesion and differentiation of primary epidermal cells were observed on various surfaces, dependent on the applied modification of these polymer surfaces, the cell shape, proliferation and differentiation range between apoptotic cells and cells showing progenitor-like properties. Conclusions: A broad range of cells can be isolated with different modifications of polymers. The modifications of the polymers must be adapted to the conditions in the extracellular matrix and gentle methods to detach cells after modification must be developed. The long-term objective is the effective isolation and cultivation of adult stem cells with these newly-developed biocompatible and micro- and nanostructured cell culture systems.