Rajora MA, Dhaliwal A, Zheng M, Choi V, Overchuk M, Lou JWH, Pellow C, Goertz D, Chen J, Zheng G

Advanced Science

DOI: 10.1002/advs.202304453

Microbubble‐enabled focused ultrasound (MB‐FUS) has revolutionized nano and molecular drug delivery capabilities. Yet, the absence of longitudinal, systematic, quantitative studies of microbubble shell pharmacokinetics hinders progress within the MB‐FUS field. Microbubble radiolabeling challenges contribute to this void. This barrier is overcome by developing a one‐pot, purification‐free copper chelation protocol able to stably radiolabel diverse porphyrin‐lipid‐containing Definity® analogues (pDefs) with >95% efficiency while maintaining microbubble physicochemical properties. Five tri‐modal (ultrasound‐, positron emission tomography (PET)‐, and fluorescent‐active) [64Cu]Cu‐pDefs are created with varying lipid acyl chain length and charge, representing the most prevalently studied microbubble compositions. In vitro, C16 chain length microbubbles yield 2–3x smaller nanoprogeny than C18 …