Study of drug delivery to vascular wall with a heating ex vivo

We studied the drug delivery methodology on a vascular wall with a heating to improve drug delivery performance. The drug delivery has been used for hyperplasia suppression such as the drug eluting stent. We think thermal denature of vascular collagen might lengthen drug penetration depth to the media because of collagen structure change. The drug concentration and penetration depth in vascular were measured by a fluorescent microscope after 15 s of immersing vascular pieces in heated 3.5 μg/ml Rhodamine B solution. The heating temperature was set to 50-70 and 37°C for control. The drug concentration and penetration depth increased with heating temperature increasing. The drug concentration was 10-10⁴ times higher than the control. The penetration depth was 2-9 times longer than the control. We found possibility of drug delivery performance improvement by the means of thermal denatured collagen in the vascular wall.