Long-Term In Vivo Glucose Monitoring by Luminescent Nanoparticles

Diabetes mellitus is a chronic and noncommunicable disease with complications found in the retina, heart, kidneys and neural system. Effective monitoring of blood glucose levels is an important tool for the prevention, diagnosis and management of diabetes. Optical sensors with an extended service time and infection risk mitigation have attracted a great deal of research interest in continuous glucose detection. However, their practical application for glucose monitoring is still constrained by the side effects of ultraviolet excitation light and operational reliability in subcutaneous tissues. Herein, glucose transducers were engineered with an optimized excitation wavelength and injectable platform.

We developed a continuous glucose monitoring system based on a visible-light excited nanoparticle transducer. We experimentally demonstrated that the nanoparticle transducer showed promise for sensitive glucose detection. The visible-light-excited transducer demonstrated potential in long-term and high-frequency monitoring in practical applications with reduced side effects compared with ultraviolet radiation.

Furthermore, we showed an implantable hydrogel platform embedded with luminescent polymer dots (Pdots) for sensitive and long-term glucose monitoring. We used Pdots in a polyacrylamide hydrogel matrix to construct an implantable transducer. The hydrogel-Pdot transducer showed bright luminescence with a ratiometric response to glucose changes. The in vitro and in vivo sensitivities of the hydrogel implant were enhanced by varying the enzyme concentration and injection volume. After implantation, the hydrogel with the Pdot transducer remained at the implant site for 1 month without migration and could be removed from the subcutaneous tissue for further analysis.

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