Degradable conjugated polymer particles for photoacoustic imaging and drug delivery

Conjugated polymer particles are stable imaging probes for biomedical analysis, offering high fluorescence and photoacoustic contrast with low cytotoxicity. They are non-bleaching, tunable in resonance frequency for specific imaging modalities, and functionalizable for targeted detection of pathological tissues. However, their non-biodegradability limits clinical use due to potential accumulation and adverse side effects. I will present the synthesis of imidazole-based conjugated polymer particles, which exhibit either strong fluorescence or high photoacoustic contrast, depending on the co-polymer structure. The imidazole units can be oxidized, degrading the particles into small, water-soluble molecules. This oxidative degradation is mediated by activated macrophages, immune cells that scavenge foreign particles in the body. This strategy offers a pathway to biodegradable imaging probes and expands possibilities for drug delivery and transient organic electronics and optoelectronics at the biointerface.