Basic study of effects on the smooth muscle cells' proliferation with novel short-term thermal angioplasty in vitro and in vivo

We investigated the effect on smooth muscle cells' proliferation with stretch-fixing in both in vitro and in vivo porcine study to determine the optimum heat condition of novel short-term thermal angioplasty, Photo-thermo Dynamic Balloon Angioplasty (PTDBA). With PTDBA, we have obtained the sufficient arterial dilatation by short-term heating (< 15 s, < 70 °C) and low dilatation pressure (< 0.4 MPa) without excessive neo-intimal hyperplasia on chronic phase. The smooth muscle cells were found to be fixed with stretched shape in vascular wall after PTDBA in vivo. The deformation rate of smooth muscle cells' nuclei was 1.6 ± 0.1 after PTDBA (15 s, 65 °C, 0.35 MPa). The smooth muscle cells, which were extracted from porcine arteries, were cultured on the specially designed equipment to give stretch-fixing stimulus in vitro. The cell proliferation was inhibited at 20 % stretching compared to 15 % stretching significantly (p < 0.05). The immunostaining specimens of basic Fibroblast Growth Factor (bFGF) and its receptor FGFR-1 were made from the porcine arteries in vivo. We found that the expressions of bFGF and FGFR-1 in the media were not observed after PTDBA. We think that these results suggested the possibility for the inhibition of the excessive cell proliferation after PTDBA.