Vesicles tethered to microbubbles by hybridized DNA oligonucleotides: flow cytometry analysis of this new drug delivery vehicle design.

Hybridization of complementary lipid-linked DNA oligonucleotides was used to tether small unilamellar vesicles (SUVs) to the lipid monolayer shells of air-microbubbles, a new attachment design for a drug delivery vehicle to be used in tandem with ultrasound imaging. Flow cytometry was used, and a novel analysis was developed, based upon light scattering and fluorescence intensity, to quantify the fraction of microbubbles of chosen size-ranges with oligonucleotide-tethered fluorescently labeled SUVs. Fluorescence microscopy was used to verify that our methodology results in successful high-density SUV tethering to a similar fraction of the microbubbles when compared to the flow cytometry statistics.