Ultrasonic release of doxorubicin from Pluronic P105 micelles stabilized with an interpenetrating network of N,N-diethylacrylamide.

Pluronic P105 micelles sequester hydrophobic drugs and release them upon insonation with low frequency ultrasound; however these micelles dissolve relatively quickly upon dilution. The objective of this research was to determine whether stabilization of these micelles would compromise their ability to sequester and release drug. P105 micelles were stabilized with an interpenetrating network of poly (N,N-diethylacrylamide), and ultrasonically-activated release of doxorubicin (Dox) was measured by a fluorescence technique. Results showed that stabilized micelles sequestered the Dox and released it upon insonation at 70 kHz. The amount released was not significantly different from that released from P105 micelles (P=0.481), and the drug re-encapsulation upon cessation of insonation was complete. This system has potential for controlled drug delivery to insonated tissues in vivo.