Kwangmeyung Kim,† Misu Lee,† Hyungkyu Park,†§ Jong-Ho Kim,† Sungwon Kim,† Hesson Chung,† Kuiwon Choi,† In-San Kim,‡ Baik L. Seong,§ and Ick Chan Kwon*†
†Biomedical Research Center, Korea Institute of Science and Technology, 39-1 Haweolgog-Dong, Sungbook-Gu, Seoul 136-791, Korea, ‡Advanced Medical Technology Cluster for Diagnosis & Prediction, Kyungpook National University, Korea, and §Department of Biotechnology, College of Engineering, Yonsei University, Korea
Here, we report for the first time cell-permeable and biocompatible polymeric nanoparticles consisting of a polymer conjugated to a near-infrared (NIR) fluorescence (Cy5.5)-linked effector caspase-specific peptide. The close spatial proximity of the NIR fluorochromes in polymeric nanoparticles results in an autoquenched state, but polymer nanoparticles give rise to strong NIR fluorescence signal under apoptotic cells. Thus, the smart polymeric nanoparticle developed here is an attractive probe for real-time imaging of apoptosis in single cells.