AVS 60th International Symposium and Exhibition
    Biomaterial Interfaces Tuesday Sessions
       Session BI-TuP

Paper BI-TuP2
Monocyte Adhesion to Protein Functionalized Nanopatterns

Tuesday, October 29, 2013, 6:00 pm, Room Hall B

Session: Biomaterials Interfaces Poster Session
Presenter: A.S. Andersen, Aarhus University, Denmark
Authors: A.S. Andersen, Aarhus University, Denmark
D.S. Sutherland, Aarhus University, Denmark
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Through a biofunctionalized nanopattern proteins are presented in circular nanopatches, which can range from 66nm-3μm in size. These protein nanopatches are used to study cell binding, specifically in regards to ligand clustering. Monocytes are the precursors for our body’s macrophages, the scavenger cells, which for example help during inflammation and to remove apoptotic cells. Monocytes are found in the blood and needs to be recruited to sites of inflammation. This happens in four stages, rolling, binding, diapedesis and migration. The focus of this research is in the first two stages. During binding an integrin, LFA1, on the monocyte binds to its ligand, ICAM1, on the epithelial cells and it is known that these form focal adhesions (FA). The size of the FA, needed to get a strong binding, is not known. This research uses a nanopattern (1), biofunctionalized through a serial protein deposition (2) mimicking FA ICAM1 patches. The binding of THP1 cells to 100-800nm sized ICAM1 nanopatterns will be shown. It illustrates a cut off in size where the cell binding disappears indicating that there is a crucial size of FA for monocytes to adhere.

Further, results showing a protein nanopattern made inside a microfluidic channel are presented. The nanopattern consists of circular gold covered holes 800nm in diameter, in a PLL-g-PEG covered SiO2 surface. The gold holes have been biofunctionalized through a serial protein deposition which gives an oriented antibody pattern, with the possibility to change to any protein with a FC domain attached. The microfluidic setup will allow for cell studies under flow and opens up the opportunity to mimic the flow conditions found in the blood stream during cellular adhesion, which have been shown to be an important factor in monocyte adhesion.

1: Jenny Malmström, Brian Christensen, Hans P. Jakobsen, Jette Lovmand, Rasmus Foldbjerg, Esben S. Sørensen, and Duncan S. Sutherland. Large Area Protein Patterning Reveals Nanoscale Control of Focal Adhesion Development. Nano letters, Vol 10, 686-694, 2010.

2: Stine H. Kristensen, Gitte A. Pedersen, Lene N. Nejsum and Duncan S. Sutherland. Nanoscale E-Cadherin Ligand Patterns Show Threshold Size for Cellular Adhesion and Adherence Junction Formation. Nano Letters, 12(4), 2129-2133 2012.