Fluorescent poly(β-amino ester)s containing aza-BODIPYs as theranostic agents for bioimaging and photodynamic therapy

Photodynamic therapy (PDT) as a promising approach in cancer treatment has garnered significant attention due to its minimal invasiveness and low toxicity, as well as its ability to avoid side effects and facilitate combination therapies. The photosensitizer (PS) is the key component of PDT and can be employed in the diagnosis or visualization of cells. Herein, a water-dispersible, biodegradable and fluorescent poly(β-amino ester) (PBAE) based PS was developed for efficient PDT and imaging. The PBAE was specifically designed and synthesized to incorporate fluorescent groups, such as aza-BODIPY, and water soluble poly(ethylene glycol) segments into the polymer backbone by aza-Michael addition-based poly-condensation polymerization. Subsequently, the amine-end functionalized PBAEs with different aza-BODIPY contents (3.6 and 7.2 mol%) were end-capped with folic acid to increase the cancer-cell-targeting potential of the polymers. The polymeric PSs were then tested on brain tumor (U87-MG), cervical tumor (HeLa) and healthy (HUVEC) cell lines for the dual modality of imaging and PDT. The polymeric PSs demonstrated significant anti-cancer potential as evaluated via reactive oxygen species generation, photocytotoxicity, colony formation and cell invasion assays.