Dependence of perpendicular pressure to luminal surface on heating drug delivery performance using a laser-mediated thermal balloon with porcine carotid artery walls ex vivo

We studied the dependence of a perpendicular pressure to the luminal surface on the heating drug delivery performance using a laser-mediated thermal balloon with porcine carotid artery walls ex vivo. We proposed the combination use of our laser-mediated thermal balloon and drug coated balloon (DCB) to enhance a drug delivery performance. We prospected that the perpendicular pressure, which was applied directly to the luminal surface by balloon dilatation, would enhance the quantity of DCB drug delivered into artery wall. To simulate our laser thermal balloon heating, 63°C preheated artery samples were prepared by heated saline dropping for 15 s, and then these samples were dipped in 37°C saline for 15 s. Non-heated artery samples were prepared by dipping in 37°C saline for 30 s. The perpendicular pressure up to 10 atm corresponding to DCB dilatation pressure was added directly to these artery samples by fluorescence Rhodamine B solution for 30 s. The quantity of drug delivered was microscopically measured with fluorescence brightness in the cross-section of the drug delivered artery samples. We found drastic drug delivery increase at 8 atm using the pre-heated artery sample. Delamination of intima layer was observed by EVG stained cross-sectional specimens with 8 atm in the pre-heated artery sample. We think this drastic pressure dependence on the heating drug delivery performance might be corresponding to increase in permeability of drug into the artery wall originated to morphology change in intima.