Open Access

Biodegradable polymers play a crucial role in biomedical applications, particularly as nanocarriers in drug delivery. While labeling the polymers with fluorescent dyes facilitates monitoring their biodistribution and post cellular uptake, tracking polymer degradation within biological systems remains a challenge. This raises important unanswered questions regarding the fate of the polymers, their degradation products, and the degree of their degradation within biological systems. In this study, we developed a novel dynamic biodynamer (BDP-Lys) composed of BODIPY and lysine-hydrazide monomers linked by reversible dynamic covalent bonds, designed to control the fluorescence of BODIPY by degradation. The BDP-Lys undergoes pH-responsive degradation, leading to recovery of quenched BODIPY and enhanced fluorescence emissions, thereby enabling direct monitoring of intracellular polymer degradation. Physicochemical characterization revealed its molecular weight, filament-like morphology, and a notable 12-fold increase in fluorescence intensity at acid-induced degradation. In vitro studies demonstrated excellent biocompatibility, efficient cellular uptake and a threefold increase in fluorescence due to polymer degradation in mammalian cells, resulting in a maximum of 17 % monomer release in the first 24 h. Thus, BDP-Lys emerges as a promising tool for exploring polymer behavior in biological systems, providing real-time insights into degradation and offering new opportunities to address unresolved questions in the field.