Specialized pro-resolving lipid mediators (SPM), such as resolvin D1 (RvD1), attenuate inflammation and improve vascular remodeling in small animal vascular injury models. We describe the translational development of thin-film sustained-release devices with Benzo-RvD1 (Benzo), a synthetic analog of RvD1. An ovine bypass graft model was used to evaluate perivascular delivery. Lab-scale devices were translated toward clinical devices through a development effort with a medical device contract manufacturing organization (CMO). Pre-clinical devices were applied to ovine carotid artery bypass grafts with saphenous vein. Either a 25% pluronic gel matrix (n = 8) or a thin film device (n = 8) was applied to each anastomosis with unloaded Control or Benzo-loaded test articles. Angiography was performed at implantation and harvest, plasma was collected for pharmacokinetics, and grafts were harvested at 4 weeks for histology. A GMP-ready approach to manufacture was identified with necessary engineering controls to mitigate defects. Terminal irradiative sterilization was found suitable for polymers but negatively impacted Benzo levels. Aneurysmal dilation was seen in all explanted vein grafts. Thin film devices were associated with reduced lumen radius to total wall thickness ratio (p < 0.05), increased adventitial inflammation (p < 0.001), and reduced collagen (p < 0.01). There was no difference in total wall thickness between vehicle and drug. Benzo was detected in plasma at implantation in the gel cohort but was otherwise absent across all other conditions and time points. Thin film devices were easily applied to bypass graft anastomoses in vivo. Unexpected aneurysmal dilation and outward remodeling of ovine vein grafts obscured hypothesis testing, and alternate models should be evaluated. PLGA-based films increased adventitial inflammation, which was counterproductive to the mode of action of the Benzo therapeutic. These findings highlight some of the challenges of preclinical development for SPM therapeutics and perivascular drug delivery. This work presents the development of devices to reduce inflammation following vascular surgery. Devices are thin films that conform around surgical locations such as bypass grafts and release a novel therapeutic agent to resolve inflammation more quickly. Existing methods of small-scale production were adapted for large-scale manufacture, and the resulting devices were then tested in a large-animal model of bypass surgery. This work highlights some of the key challenges faced in advancing a technology from laboratory to commercial manufacture, which is required for subsequent human trials.
Kim et al. (Fri,) studied this question.