2019 Volume 8 Pages 38-44
We studied the effects of interactive pressure on the delivery of hydrophobic rhodamine B to ex vivo heated artery walls to determine the optimal drug delivery conditions. The heated artery samples, which were maintained at 63℃ on the intimal surface, were prepared by heating for 15 s. Interactive pressure up to 10 atm was directly applied with a rhodamine B solution to the artery samples from the intima side over 30 s. The fluorescence brightness distribution of rhodamine B in the samples were measured microscopically to investigate the quantity and depth of drug delivery. We found a decrease in the depth of drug delivery in the heated artery samples compared with the reference artery samples. This decrease in drug delivery depth may have resulted from increased hydrophobic binding of rhodamine B at the intima because of heating. We also found a significant increase in quantity of drug delivery at a certain interactive pressure in the heated artery samples. Hematoxylin-eosin staining of cross sections of pressurized heated artery samples revealed delamination of the intima and extension of the internal elastic lamina. We hypothesize that the dependence of drug delivery quantity on the interactive pressure is attributed to morphological changes in the intima and the internal elastic lamina.