In Vivo visualization of microplastic degradability and intestinal functional responses in a plastivore insect

The plastivore insect Tenebrio molitor demonstrates significant potential for the rapid biodegradation and bioremediation of micro(nano)plastics. However, real-time visualization of the digestive degradation and removal of microplastics (MPs) during intestinal transit, along with the associated in vivo intestinal functional responses, remains challenging. Here, we developed second near-infrared (NIR-II) window aggregated-induced emission (AIE) MPs of two sizes (29.8 μm and 299.5 μm, respectively) to enable real-time monitoring of MPs removal in T. molitor larvae, and quantified the degradation kinetics. Our findings revealed that small MPs were digested and passed through the intestine more rapidly compared to large MPs, in strong contrast with patterns observed in organisms lacking plastic-degrading capacity. Digestive removal was more pronounced in the posterior than in the anterior midgut. A NIR-II peroxynitrite probe (NIR-ONOO^-) was synthesized to investigate the intestinal functional responses to MPs biodegradation. Generation of reactive nitrogen species (RNS) was extensive during feedstock digestion in the intestine. The larvae instinctively modulated the ONOO^- levels and heterogeneously redistributed the ONOO^- in response to MPs biodegradation, with a more pronounced effect observed in larvae fed large MPs. This work presents a robust trafficking technology for the dynamic and in vivo visualization of micro(nano)plastics removal and bioremediation in plastivore species.