Dual-Targeted Theranostic Delivery of miRs Arrests Abdominal Aortic Aneurysm Development.

Abdominal aortic aneurysm (AAA) is an often deadly disease without medical, non-invasive treatment options. The upregulation of vascular cell adhesion molecule-1 (VCAM-1) on aortic endothelium provides an early target epitope for a novel biotechnological theranostic approach. MicroRNA-126 was used as a therapeutic agent, based on its capability to downregulate VCAM-1 expression in endothelial cells and thereby reduces leukocyte adhesion and exerts anti-inflammatory effects. Ultrasound microbubbles were chosen as carriers, allowing both molecular imaging as well as targeted therapy of AAA. Microbubbles were coupled with a VCAM-1-targeted single-chain antibody (scFv) and a microRNA-126 mimic (M) constituting theranostic microbubbles (Targ-M). Targ-M downregulates VCAM-1 expression in vitro and in an in vivo acute inflammatory murine model. Most importantly, using Targ-M and ultrasound-guided burst delivery of M, the development of AAA in an angiotensin-II-induced mouse model can be prevented. Overall, we describe a unique biotechnological theranostic approach with the potential for early diagnosis and long-sought-after medical therapy of AAA.