Stimulation of vascular cells by extracellular signals - A biophysical analysis

Stimulation of vascular cells by extracellullar signals Treatment of vascular diseases often requires the selective addressing of endothelial (ECs) and smooth muscle cells (SMCs). The two vascular cell types are important for the wound healing after stent implantation. Recent research designs new materials and coatings for stents to improve the complex healing process. The aim of my work was to find and investigate different reactions in the two vascular cell types (ECs and SMCs) through surface chemistry, topography and other stimulating factors like electrical fields or applied external stretching forces. On various iridium-oxide stent coatings ECs seem to be more sensitive to chemical differences than SMCs. On PDMS micro-nano-grooves ECs and SMCs align not significant differently to the structure. Cell assays on nano-structured and bio-functionalized surfaces reveal a universal ligand distance dependency for both cell types. Upon application of uniaxial mechanical stretch or an directed electrical field, ECs and SMCs show significant different responses. General characteristics of the two cell types can be quantitatively described by an automatic controller model. These findings are promising for further studies to improve wound healing after implantation and even more to allow the artificial generation of new blood vessels (angiogenesis)

Nano- and microstructured materials for in vitro studies of the physiology of vascular cells

The extracellular environment of vascular cells in vivo is complex in its chemical composition, physical properties, and architecture. Consequently, it has been a great challenge to study vascular cell responses in vitro, either to understand their interaction with their native environment or to investigate their interaction with artificial structures such as implant surfaces. New procedures and techniques from materials science to fabricate bio-scaffolds and surfaces have enabled novel studies of vascular cell responses under well-defined, controllable culture conditions. These advancements are paving the way for a deeper understanding of vascular cell biology and materials–cell interaction. Here, we review previous work focusing on the interaction of vascular smooth muscle cells (SMCs) and endothelial cells (ECs) with materials having micro- and nanostructured surfaces. We summarize fabrication techniques for surface topographies, materials, geometries, biochemical functionalization, and mechanical properties of such materials. Furthermore, various studies on vascular cell behavior and their biological responses to micro- and nanostructured surfaces are reviewed. Emphasis is given to studies of cell morphology and motility, cell proliferation, the cytoskeleton and cell-matrix adhesions, and signal transduction pathways of vascular cells. We finalize with a short outlook on potential interesting future studies