| 초록 |
Molecular imaging in tumor biology is becoming one of the most active scientific and clinical research areas. Especially, optical imaging based on fluorescence resonance energy transfer (FRET) phenomena has emerged as an important technique to describe clinical targets in vivo. In the present work, we show a polymeric FRET system that emits specific fluorescence upon responding to lowering pH. As a pH sensitive moiety, sulfadimethoxine is chosen and is conjugated with methacrylol chloride to synthesize methyl methacrylate based sulfadimethoxine monomer (MbSDM). Pyrene and coumarin are selected as FRET donor and FRET acceptor, respectively. For synthesis of linear FRET system, pyrene is modified to atom transfer radical polymerization (ATRP) initiator of MbSDM for preparation of pH sensitive polymeric backbone. For synthesis of multi-arm FRET system, pyrene with multi-initiating center is used as ATRP initiator of MbSDM. The sequential ATRP of methyl methacrylate based coumarin monomer is performed to position coumarin at the end of polymeric backbone. This polymeric backbone could be reversibly changed in end-to-end distance, which comes from the unique property of pH sensitive sulfadimethoxine. FRET from pyrene to coumarin as a function of pH change will be studied. |
