Annexin A5-Conjugated Polymeric Micelles for Dual SPECT and Optical Detection of Apoptosis

摘要

Imaging of apoptosis can allow noninvasive assessment of disease states and response to therapeutic intervention for a variety of diseases. The purpose of this study was to develop and evaluate a multimodal nanoplatform for the detection of apoptosis.MethodsTo modulate the pharmacokinetics of annexin A5, a 36-kDa protein that binds specifically with phosphatidylserine, annexin A5 was conjugated to polyethylene glycol-coated, core-crosslinked polymeric micelles (CCPM) dually labeled with near-infrared fluorescence fluorophores and a radioisotope (indium 111). To evaluate the specificity of the binding of annexin A5-CCPM to apoptotic cells, both fluorescence microscopy and cell binding studies were performed in vitro. Pharmacokinetics, biodistribution, dual nuclear and optical imaging, and immunohistochemical studies were carried out in 2 xenografted tumor models to evaluate the potential applications of annexin A5-CCPM.