Objective: Motexafin lutetium (Lu-Tex, Antrin® Injection) is a photosensitizer that selectively accumulates in atheromatous plaque where it can be activated by far-red light. The localization and retention of intra-arterially administered Lu-Tex and its efficacy following activation by endovascularly delivered light (photoangioplasty) was evaluated. Methods: Bilateral iliac artery lesions were induced in 17 rabbits by balloon denudation, followed by a high cholesterol diet. Lu-Tex distribution within the atheroma was examined (n=8) following local injection. Fluorescence spectral imaging and chemical extraction techniques were used to measure Lu-Tex levels within the atheroma and adjacent normal tissue. Photoactivation was performed 15 min following Lu-Tex administration (180 J/cm fiber at 200 mW/cm fiber). Two weeks post photoangioplasty, vessels were harvested and hematoxylin and eosin (H&E) and RAM11 (macrophages) staining was performed. Results: Local delivery of Lu-Tex achieved immediate high concentrations within plaque (mean 40× control iliac atheroma). Mean percent plaque area in the treated segments was significantly lower than in the non-treated contralateral lesions (73 vs. 82%, P<0.01). No medial damage was observed. Quantitative analysis using RAM11 positive cells revealed significant reduction of macrophages in treated lesions in both the intima (5 vs. 22%, P<0.01) and in media (8 vs. 23%, P<0.01) compared to untreated contralateral segments. Conclusions: Local delivery provides high levels of Lu-Tex selectively within atheroma. Photoactivation results in a significant decrease in macrophage and a small decrease in atheroma burden without damage to the normal vessel wall. © 2001 Elsevier Science B.V.
M., H., K.W., W., J., P., R.A., M., W., B., P.G., Y., & A., Y. (2001). Photoangioplasty with local motexafin lutetium delivery reduces macrophages in a rabbit post-balloon injury model. Cardiovascular Research, 49(2), 449–455. https://doi.org/10.1016/S0008-6363(00)00278-9