Cell Surface Modification with Lipophilic Linkers

Cell surface modification with bioactive groups is useful for adjusting their interactions and responses to chemical and physical stimuli. One method of surface modification is overexpression of membrane receptors, but this is time-consuming and restricted to membrane proteins. When non-protein molecules are needed for functionalization, chemical addition of bioactive groups may affect cell viability due to the use of harsh chemicals. To mitigate these shortcomings, we investigated the modification of cell surfaces by employing lipid-like linkers, which not only act quickly but also minimize the use of harsh chemicals. These lipid-like linkers carry a bioactive molecule at one end, while the other end self-inserts into target membranes. To achieve cell surface functionalization, we employed sheep red blood cells as model membranes and biotinylated FSL as lipophilic linkers. The biotin group exploited the specific biotin-streptavidin interaction to detect successful membrane functionalization. For quantitative measurements, we employed the Kinetic Exclusion Assay technology, which allowed us to determine the density of added bioactive groups on the cell surface and the affinity of the streptavidin-biotinylated linker interaction using fluorescence. We concluded this approach may be utilized for non-destructive modification of cell surfaces for a wide variety of biomedical and scientific applications.