Ultrasound-Based Molecular Imaging of Tumors with PTPmu Biomarker-Targeted Nanobubble Contrast Agents.
Ultrasound imaging is a widely used, readily accessible and safe imaging modality. Molecularly-targeted microbubble- and nanobubble-based contrast agents used in conjunction with ultrasound imaging expand the utility of this modality by specifically targeting and detecting biomarkers associated with different pathologies including cancer. In this study, nanobubbles directed to a cancer biomarker derived from the Receptor Protein Tyrosine Phosphatase mu, PTPmu, were evaluated alongside non-targeted nanobubbles using contrast enhanced ultrasound both in vitro and in vivo in mice. In vitro resonant mass and clinical ultrasound measurements showed gas-core, lipid-shelled nanobubbles conjugated to either a PTPmu-directed peptide or a Scrambled control peptide were equivalent. Mice with heterotopic human tumors expressing the PTPmu-biomarker were injected with PTPmu-targeted or control nanobubbles and dynamic contrast-enhanced ultrasound was performed. Tumor enhancement was more rapid and greater with PTPmu-targeted nanobubbles compared to the non-targeted control nanobubbles. Peak tumor enhancement by the PTPmu-targeted nanobubbles occurred within five minutes of contrast injection and was more than 35% higher than the Scrambled nanobubble signal for the subsequent two minutes. At later time points, the signal in tumors remained higher with PTPmu-targeted nanobubbles demonstrating that PTPmu-targeted nanobubbles recognize tumors using molecular ultrasound imaging and may be useful for diagnostic and therapeutic purposes.
['Johansen|Mette L|ML|', 'Perera|Reshani|R|', 'Abenojar|Eric|E|0000-0002-2733-4006', 'Wang|Xinning|X|', 'Vincent|Jason|J|', 'Exner|Agata A|AA|0000-0003-3913-7066', 'Brady-Kalnay|Susann M|SM|0000-0003-4635-4093']
D000818:Animals D014408:Biomarkers, Tumor D003287:Contrast Media D042783:Endothelial Cells D005260:Female D006801:Humans D007668:Kidney D008819:Mice, Nude D057054:Molecular Imaging D053758:Nanoparticles D009369:Neoplasms D054623:Receptor-Like Protein Tyrosine Phosphatases, Class 2 D014463:Ultrasonography
molecular imaging PTPmu nanobubbles receptor protein tyrosine phosphatase dynamic contrast enhanced ultrasound time intensity curve ultrasound contrast agents