Pretreatment with intraluminal rapamycin nanoparticle perfusion inhibits neointimal hyperplasia in a rabbit vein graft model.
OBJECTIVE
Poly lactic-co-glycolic acid nanoparticles (PLGA-NP) are widely used as a biodegradable biomaterial in medicine. Rapamycin-eluting stents have been used for prevention of restenosis during surgery. This study investigated the effect of pretreatment with intraluminal perfusion of carbopol-encapsulated rapamycin-loaded PLGA nanoparticles (RAP-PLGA-NP) on neointimal hyperplasia in a rabbit vein graft model.


METHODS
A segment of common carotid artery was replaced with a segment of external jugular vein in 60 rabbits which were then separated into four treatment groups, ie, Group 1, in which vein grafts were pretreated with intraluminal RAP-PLGA-NP perfusion, Group 2 in which vein grafts underwent equivalent empty vehicle (PLGA-NP) perfusion, Group 3, in which vein grafts received no treatment, and Group 4, which served as a sham operation group receiving normal vein contrast. On postoperative day 28, the grafts and normal veins were harvested for histologic examination, flow cytometry analysis, and high-performance liquid chromatography measurement.


RESULTS
Compared with Group 1, the intima of the grafts were thickened, the ratio of intimal area to vessel area increased, and the collagen volume index of the vein grafts increased significantly in Groups 2 and 3. The cell proliferation index in Group 1 (21.11 ± 3.15%) was much lower than that in Group 2 (30.35 ± 2.69%) and in Group 3 (33.86 ± 8.72%). By high-performance liquid chromatography measurement, retention of rapamycin was detected in Group 1 (11.2 ± 0.37 μg/10 mg) 28 days after single drug perfusion.


CONCLUSIONS
Pretreatment with intraluminal RAP-PLGA-NP perfusion may inhibit neointimal hyperplasia in vein grafts by penetrating into local tissue and limiting cell proliferation.
Department of Cardiovascular Surgery, Qilu Hospital of Shandong University, Jinan, People’s Republic of China.
Kai
K
Liu
Guangqing
G
Cao
Xiquan
X
Zhang
Ruifang
R
Liu
Weiwei
W
Zou
Shuming
S
Wu
D000818:Animals; D006083:Graft Occlusion, Vascular / Q000473:pathology / Q000517:prevention & control; D066298:In Vitro Techniques; D007601:Jugular Veins / Q000187:drug effects / Q000473:pathology / Q000637:transplantation; D019344:Lactic Acid / Q000737:chemistry; D023421:Models, Animal; D050997:Nanomedicine; D053758:Nanoparticles / Q000008:administration & dosage* / Q000737:chemistry; D058426:Neointima / Q000473:pathology / Q000517:prevention & control*; D010477:Perfusion; D011100:Polyglycolic Acid / Q000737:chemistry; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011817:Rabbits; D020123:Sirolimus / Q000008:administration & dosage* / Q000097:blood / Q000493:pharmacokinetics; D014182:Transplantation, Autologous
D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D020123:Sirolimus