Ultrasound contrast agent loaded with XXXX as a theranostic microdevice.

@entity137 @entity4832 @entity174 @entity842 @entity741
The current study describes novel multifunctional polymer-shelled microbubbles (MBs) loaded with @entity842 (NO) for integrated therapeutic and diagnostic applications (ie, theranostics) of @entity741 . We used gas-filled MBs with an average diameter of 4  m stabilized by a biocompatible shell of @entity4832 . In vitro acoustic tests showed sufficient enhancement of the backscattered power (20 dB) acquired from the MBs' suspension. The values of attenuation coefficient (0.8 dB/cm MHz) and phase velocities (1,517 m/s) were comparable with those reported for the soft tissue. Moreover, polymer MBs demonstrate increased stability compared with clinically approved contrast agents with a @entity174 threshold of about 900 kPa. In vitro chemiluminescence measurements demonstrated that dry powder of NO-loaded MBs releases its gas content in about 2 hours following an exponential decay profile with an exponential time constant equal to 36 minutes. The application of high-power ultrasound pulse (mechanical index =1.2) on the MBs resuspended in saline decreases the exponential time constant from 55 to 4 minutes in air-saturated solution and from 17 to 10 minutes in degassed solution. Thus, ultrasound-triggered release of NO is achieved. @entity137 tests indicate that phagocytosis of the MBs by macrophages starts within 6-8 hours. This is a suitable time for initial diagnostics, treatment, and monitoring of the therapeutic effect using a single injection of the proposed multifunctional MBs.
