OBJECTIVETo assess the efficiency of eluting stent coated with arsenic trioxide (As(2)O(3)) suspended in poly-L-lactic acid (PLLA) to prevent in-stent restenosis in rabbits.

METHODSForty-five male New Zealand white rabbits were assigned to three groups (n = 15 for each group) at random: uncoated stents, stents coated with PLLA or stents coated with As(2)O(3) in PLLA. Animals were euthanized 28 days after stent implantation into the iliac arteries of rabbits. Neointimal thicknesses and apoptosis of vascular smooth muscle cell (VSMC) were measured. Stents coated with As(2)O(3) in PLLA were implanted in another 48 male New Zealand white rabbits, As(2)O(3) concentrations in serum and arterial tissue at implantation site were measured at 2 h and 1, 3, 7, 14, 28 days after As(2)O(3) eluting stent implantation (n = 8 for each time point).

RESULTSNeointimal hyperplasia was significantly reduced 51% and 31% and apoptosis significantly increased (21.0 +/- 3.3; 6.2 +/- 1.9(*); 5.3 +/- 2.1(*), (*)P < 0.01 vs. As(2)O(3) eluting stent) with As(2)O(3) eluting stent, versus PLLA-coated stents and uncoated stents. As(2)O(3) concentrations in arterial tissue at implantation site were 18.6 +/- 9.1 (ng/mg) at 1 day and 0.3 +/- 0.1 (ng/mg) at 28 days after stent implantation.

CONCLUSIONSAs(2)O(3) coated stents released As(2)O(3) to local tissue for at least 28 days, suppressed neointimal hyperplasia in rabbit iliac arteries and increased local VSMC apoptosis might be one of the mechanisms for inhibiting restenosis by As(2)O(3) coated stents.