Coencapsulation of lipid microbubbles within polymer microcapsules for contrast applications

In this work, the authors examine the acoustic response generated by the coencapsulation of phospholipid shelled microbubbles within the aqueous core of polymer microcapsules and its feasibility as an ultrasound contrast agent. The addition of the polymer shell provides the added benefit of approximately doubling the inertial cavitation threshold of the microbubbles contained within. The feasibility of the utilisation of the coencapsulated contrast agent as a drug delivery vehicle is also discussed. It is concluded that the coencapsulated contrast agent provides contrast similar to that of unencapsulated microbubbles, both in acoustic response and image intensity of contrast to tissue.