Functionalizing Cell Membranes with DNA Origami for Multiplexed Biomolecular Sensing

The plasma membrane is the primary communicating interface between the cell and extracellular environment. Thus, the ability to engineer new functions into the cell membrane to externally monitor or manipulate cellular interactions is of great significance. Previous studies have focused on engineering cell surface proteins or incorporating synthetic protein constructs into the cell membrane, which are often highly challenging. Therefore, designing a robust approach to incorporate nanodevices with diverse structural and dynamic functions into the cell membrane can enable engineering of the cell surface as a functional material. DNA origami has enabled the fabrication of nanostructures with diverse biological applications such as molecular measurements, and biomolecular sensing1. Hence, to extend the functions of DNA nanostructures to the context of the cell plasma membrane, we developed a robust and controllable approach to incorporate DNA origami nanostructures into cell membranes2. Our approach enables the development of cell‐based multiplexed detection tools to examine and report the presence of various extracellular biomolecular and potentially biophysical cues. Our method implements a cholesterol conjugated DNA strand serving as the membrane incorporated oligo (MIO) to serve as an anchoring site for the binding of a DNA origami membrane bound breadboard (MBB). First, we confirmed the functionalization of the cell membrane with MIO by visualization of a complementary fluorescent oligo (Fig. 1A). Next, we utilized an intermediate oligo that binds to the MIO and extends a single‐stranded DNA binding site away from the surface for subsequent binding of the MBB (Fig. 1B). Using this functionalization scheme, we effectively coated the surface of five cell types with MBB structures (Fig. 1C, image shown for CH12.LX B Cells). In addition, confocal imaging techniques confirmed MBB presence around the cell periphery (Fig. 1D). Next, we leveraged this approach to facilitate controllable cell‐cell adhesion. We used oligos that connect two MBBs by binding to extended overhangs on the outward facing side. We used this approach to facilitate controllable binding between two heterotypic and homotypic cells functionalized with MBB structures (Fig. 2A). Finally, we used the overhangs on the outward facing side to incorporate aptamers that can detect the presence of extracellular single stranded DNA (Fig. 2B) and platelet‐derived growth factor (PDGF). We have developed a robust approach to functionalize the cell membrane with 3D DNA origami nanostructures. Our approach enables controlled cell‐cell attachment to construct higher order cellular assemblies. In addition, MBB can serve as a versatile and multiplexed cell‐based platform to monitor and report biomolecular or potentially biophysical cues in the cell surrounding environment. Support or Funding Information Funding was provided by National Institute of Health grant R01HL14194. This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .