Heparin- and basic fibroblast growth factor-incorporated stent: a new promising method for myocardial...

The problem for transmyocardial revascularization is the occlusion of transmural channels. We have developed a novel heparinized basic fibroblast growth factor (bFGF)-incorporating tubular stent by polymer materials of poly D, L-lactic/glycolic acid (PLGA) and polycaprolactone (PCL) with preferable biocompatibility and mechanical elasticity. This study investigated the effect of this new stent on transmyocardial perfusion.

Miniswine were grouped into bare stent group (BS), heparinized stent group (HS), and bFGF- and heparin-incorporated stent group (HBS). Two stents were implanted into the ischemic region. At 6 wk postoperatively, von Willebrand Factor (vWF) and Ki-67 antigen were immunohistologically stained. The expression of transforming growth factor-beta3 (TGF-β3), vascular endothelial growth factor (VEGF), interleukin-1beta (IL-1β), and vWF mRNA from the cardiac tissue around the stent were performed by reverse transcription polymerase chain reaction (RT-PCR). Left ventricular function and myocardial perfusion by echocardiography and nuclear scanning were also documented.

Ki-67 positively-staining proliferating cells, expressions of proangiogenic factors of TGF-β3, VEGF, vWF, IL-1β, and vascular density in HBS group were significantly different from those in HS and BS groups (P < 0.05). Neovascularization with endothelization, improvement in perfusion, and fractional shortening in BHS and HS groups were significantly better than those in BS group (P < 0.001).

Heparinized bFGF-incorporating stent developed in the present study may keep the myocardial channel open with full luminal endothelization. By inducing cellular migration and expression of angiogenic factors, this novel stent may further enhance neovascular formation, increase myocardial perfusion, and improve cardiac function.