Stent Coating with eNOS Plasmid DNA-Encapsulated Lipopolyplexes. (A) Lipopolyplexes (LPPs) were prepared by plasmid DNA complexation with poly(beta-amino ester) followed by encapsulation in cationic liposomes. Transmission electron microscopy (TEM) analysis confirmed the size of approximately 200-400 nm and spherical shape. (B) Endothelial nitric oxide synthase (eNOS) expressing plasmid vector with 3.0 kB pVAX1 vector and cDNA encoding for human eNOS. Gel electrophoresis shows 1-10 kB ladder in lane 1, intact plasmid in lane 2, and the fragments after restriction enzyme digestion in lane 3. (C) Fabrication and expansion of LPP-immobilized type B gelatin-coated Relysis Mini Legend® stainless steel coronary stents. LPP were formulated with rhodamine-labeled phospholipids for fluorescence microscopy. The stent expansion was initiated with up to 8 atmospheres of pressure over 5 seconds. (D) In vitro release profile of rhodamine-labeled lipopolyplexes from poly(D,L-lactide-co-glycolide) (PLGA)/type B gelatin-coated stents. Lipopolyplex release was examined from stents with no PLGA, with 12 mg of PLGA, and with 24 mg of PLGA coatings.