Abstract 377: Development of a Cell-Based Assay for In Vitro Assessment of Ultrasound Enhanced Bevacizumab Release from Echogenic Liposomes for Delivery into Atherosclerotic Adventitia
Introduction. Vascular endothelial growth factor (VEGF) is an important mediator of angiogenesis, not only in tumor growth, but also in vulnerable atheroma progression. Recent research has indicated that bevacizumab, an anti-cancer monoclonal antibody targeting VEGF, can inhibit atheroma progression. We have developed bevacizumab-loaded echogenic liposomes (BEV-ELIP) as an ultrasound-triggered intrinsically targeted controlled release vehicle for treatment of developing atheroma.
Hypothesis. PMA-treated human umbilical vein endothelial cell (HUVEC) cultures can serve as a means of optimizing BEV-ELIP inhibition.
Methods. Bevacizumab (1 μg/ml) was added to 18-hour HUVEC cultures in 96-well plates, followed by 10 nM phorbol 12-myristate 13-acetate (PMA) 4 hours later and incubated for 24 hours. Controls consisted of no PMA, no BEV; no PMA + BEV; and no BEV + PMA. Cells were enumerated using a hemacytometer and tetrazolium dye MTT.
Results. PMA enhanced cell proliferation by 21-50% relative to control cultures, but bevacizumab treatment of PMA cultures inhibited cell proliferation by 30-55%, to levels lower than no PMA + BEV controls (Fig. 1). Cell proliferative effects were paralleled by both cell-associated and secreted VEGF levels (determined by western blot and ELISA, respectively).
Conclusions. We have developed an in vitro cell-based assay for testing BEV-ELIP efficacy with and without ultrasound pretreatment, involving addition of a BEV-containing sample before PMA and determining the inhibition of cell proliferation. This allows us to optimize our therapeutic prior to testing in an in vivo developing atheroma model.
- © 2013 by American Heart Association, Inc.