| AVS 57th International Symposium & Exhibition | |
| Biomaterial Interfaces | Wednesday Sessions |
| Session BI2-WeM |
| Session: | Proteins & Peptides on Surfaces |
| Presenter: | S. Kristensen, Aarhus University, Denmark |
| Authors: | S. Kristensen, Aarhus University, Denmark J. Malmström, Aarhus University, Denmark J. Lovmand, Aarhus University, Denmark M. Duch, Aarhus University, Denmark D.S. Sutherland, Aarhus University, Denmark |
| Correspondent: | Click to Email |
Synthetic materials are often used for biomedical applications. Interaction of cells with the interfaces and tissue components determine the biological outcome of the device. Knowledge about the interaction between the cells and biointerfaces is hence of importance in area such as biomaterials, tissue engineering and cell culture. The interaction of the cells with its surroundings is mediated at the molecular and macromolecular level. Specific interaction with the extracellular matrix components or macromolecules in the outer membrane of adjacent cells provides signaling and communication pathways. Here patterns of extracellular matrix protein are used to study the development of cellular adhesion complexes.
Protein nanopatterns at the 100-3000 nm scale and with lateral ordering between independent ligands and controlled lateral mobility has been made by using a nanoscale chemical contrast of Au patches in a background of SiO2 by colloidal lithography. The nanostructured surfaces are made by depositing a triple polyelectrolyte layer (PDDA/PSS/PAX) at Au substrates. Latex particles self assemble at the surface governed by electrostatic forces followed by SiO2 evaporation and removal of the particles. The generated short range ordered arrays were further modified by octadecylmercaptane adsorption. The samples were subsequently treated with PLL-g-PEG for 30 min. followed by adsorption of fibronectin for 2 h. Myoblast cell(C2C12) or MDA-MB-435 cells were added to the samples and allowed to adhere to the surfaces for 6 h or 24 hours.
Fibronectin distribution at the nanopatterned surfaces was studied via liquid AFM showing that protein were adsorbed preferentially on the alkane thiol patches. SEM images showed that protein was patterned over large areas. Protein patterns of several other proteins such as Osteopontin, Vitronectin and Laminin were also demonstrated. Fluorescent microscopy showed that cells adhered to the patterns of size from 200nm and up. Small focal complexes were observed at the 200nm structures which were not linked to the actin cytoskeleton. For 500nm and 1000nm patchs cell showed small focal adhesions connected to thin actin fibers and the adhesions were limited to individual patches.
We utilize colloidal lithography to fabricate protein patterns of size from nano to micro scale and from different proteins. The patterned areas are of a sufficiently large area to carry out large scale cellular characterisation in terms of adhesion morphology and differentiation. The protein patterning makes it possible to limit the length of developing focal adhesions to single patches and hence alter the cells ability to generate forces, spread and move.