Molecular imaging of human ACE-1 expression in transgenic rats.

Objectives: The aim of this study was to develop a molecular imaging strategy that can monitor myocardial angiotensin-converting enzyme (ACE)-1 upregulation as a function of progressive heart failure.

Background: High-affinity technetium-99m-labeled lisinopril (Tc-Lis) has been shown to specifically localize in tissues that express ACE in vivo, such as the lungs. Whether Tc-Lis can also detect upregulation of ACE in the heart, by external in vivo imaging, has not been established.

Tumor-targeted HPMA copolymer-(RGDfK)-(CHX-A''-DTPA) conjugates show increased kidney accumulation.

N-(2-hydroxypropyl) methacrylamide (HPMA) copolymer-RGDfK conjugates targeting the alpha(v)beta(3) integrin have shown increased accumulation in solid tumors and promise for selective delivery of radiotherapeutics to sites of angiogenesis- or tumor-expressed alpha(v)beta(3) integrin. An unresolved issue in targeting radiotherapeutics to solid tumors is toxicity to non-target organs. To reduce toxicity of radiolabeled conjugates, we have synthesized HPMA copolymer-RGDfK conjugates with varying molecular weight and charge content to help identify a polymeric structure that maximizes tumor accumulation while rapidly clearing from non-targeted organs.

An assessment of radionuclidic impurities of (210)Po produced via neutron irradiation of (209)Bi for use in targeted alpha-particle radiotherapy.

Radionuclidic impurities of (210)Po prepared by neutron irradiation of (209)Bi via the (209)Bi(n,gamma)(210)Bi reaction were investigated. Following irradiation and ingrowth, a pure (210)Po solution was obtained by sublimation and dissolution. Results were obtained by liquid scintillation (LS) counting, isotope dilution alpha (alpha)-spectrometry, and high-purity germanium gamma-ray spectrometry.

Polymeric conjugates of mono- and bi-cyclic alphaVbeta3 binding peptides for tumor targeting.

The alphaVbeta3 integrin plays important roles in tumor-induced angiogenesis and tumor metastasis and hence, many small molecule alphaVbeta3 ligands have been developed for cancer diagnosis and therapy. Although these show good alphaVbeta3 targeting, most have suboptimal pharmacokinetics and show rapid tumor washout. We studied the biodistribution and tumor targeting properties of N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer based conjugates of mono-(RGDfK) and doubly cyclized (RGD4C) alphaVbeta3 binding peptides.