Current research has revealed the importance of a class of cell surface proteins called integrins in various vital physiological functions such as blood clotting, regulation of blood pressure, tissue blood flow, and vascular remodeling. The key to integrin functionality is its ability to mediate force transmission by interacting with the extracellular matrix and cytoskeleton. In addition, they play a role in signal transduction via their connection with the proteins in focal adhesion (FA) points. To understand the complex mechanism of cell-cell and cell-extracellular matrix (ECM) adhesion that is responsible for these diverse biochemical interactions, it is necessary to identify the integrins on cells and monitor their interaction with various ligands. To this end, for the first time, we employ surface-enhanced Raman spectroscopy (SERS) to detect integrins. The results show the capability using SERS to detect the integrins to the nanomolar concentration regime and to distinguish between two different kinds of integrins, V3 and 51, that are present in vascular smooth muscle cells (VSMCs). It is anticipated that the SERS approach will potentially help elucidate the mechanism of integrin-ligand interactions in a variety of phenomena of physiological importance.
This study reports on current work involving the use of Surface Enhanced Raman Spectroscopy (SERS) for the intracellular detection of cell constituents in mouse fibroblast cells using gold nanoshells. Gold nanoshells were acquired from Nanospectra Biosciences that are based on a silica dielectric core and an outer gold shell layer. They
have the unique property of a tunable surface plasmon resonance wavelength from the visible through the near infrared which allows control of the electromagnetic field strength on its surface. Hence gold nanoshells can serve as SERS substrates with plasmonic properties that are not aggregation dependent and thus can be expected to overcome the reproducibility problem that is generally associated with aggregation based colloidal metal nanoparticles. These results represent the first steps in the development of a nanoshell-based SERS probe to detect cell organelles and/or intracellular biochemicals with the goal of ultimately improving the ability to monitor intracellular biological processes in real time.