Microbubbles Conjoining LyP-1 as a Tumor Probe for Ultrasound Molecular Imaging: Targeting Efficiency Evaluation on Microfluidic Platform

Microbubbles promise not only as effective acoustic probes for ultrasonic molecular imaging,but also as drug carrier vehicles by conjuncting to specific antibody or ligand. Microbubble´s targeting efficiency to certain cells or moleculars is one of the major challenges of being as the acoustic probes. In this study, we developed tumor targeted contrast microbubbles by binding LyP-1 (a cyclic nonapeptide acid peptide) targeted to cancer cell. In addition, we utilized microfluidic technology to evaluate the targeted capability and efficiency of microbubbles to tumor cell surface. The system includes 8×8 chamber microfluidic array and each chamber contains eight micro cell sieves which is semicircular for cell trapping. Assisted with the controllable fluid shear stress, the microbubble´s targeted to the cell and the corresponding affinity efficiency could be quantitatively evaluated under a florescent microscope. The result demonstrated that LyP-1 is an efficient maker to be congjuated with microbubbles as tumor targeting probe. Moreover, this system is shown as a useful low-cost and high efficient in vitro platform for studying ultrasonic molecular imaging, drug-delivery and therapy.