New application of optical agent to image angiogenesis in hindlimb ischemia.

Optical agents targeting α(v)β₃ are potential tools to image the angiogenic response to limb ischemia. The left (L) femoral artery was ligated in 17 mice and sham surgery performed on the contralateral right (R) hindlimb. Seven days later, IntegriSense (2 nmol) was injected into 11 mice and 6 were probe controls. Six hours later, mice underwent optical imaging. Ratios of photon flux in the L/R limbs were calculated. Tissue was stained for α(v) , CD31, and lectin. The signal was increased in the ischemic limbs compared to contralateral legs and ratio of photon flux in L/R limb averaged 2.37. Control probe showed no hindlimb signal. IntegriSense colocalized with CD31 by dual fluorescent staining. Ratios for L/R hindlimbs correlated with quantitative lectin staining (r = 0.88, p = 0.003). Optical imaging can identify and quantify angiogenic response to hindlimb ischemia.