Visible-Light-Activated High-Density Materials for Controlled in Vivo Insulin Release

Area of Science:

• Biomaterials Science
• Drug Delivery Systems
• Photochemistry

Background:

• Traditional insulin delivery methods face challenges in achieving precise glycemic control.
• Photoactivated Depot (PAD) materials offer a light-triggered approach to insulin release.
• First-generation PAD materials demonstrated proof-of-concept but had limitations in efficiency and light penetration.

Purpose of the Study:

• To develop and evaluate second-generation insulin photoactivated depot (PAD) materials with enhanced in vivo performance.
• To utilize visible light for insulin release, improving light penetration and therapeutic efficacy.
• To engineer highly dense insulin formulations for improved release kinetics.

Main Methods:

• Synthesis of coumarin-based photocleavable linkers and their conjugation to insulin.
• Formation of insulin trimers via light-cleavable groups for controlled solubility.
• Characterization of insulin trimers using mass spectrometry and assessment of in vitro photolysis.
• Fabrication of injectable particles and evaluation of light-triggered insulin release in vitro.
• In vivo assessment of the performance of second-generation PAD materials.

Main Results:

• Developed second-generation insulin PAD materials utilizing visible light for insulin release.
• Incorporated coumarin photocleavable groups, shifting release to the visible light spectrum for better tissue penetration.
• Created highly dense insulin trimers (87% insulin dry w/w) with light-triggered solubility changes.
• Demonstrated a 28-fold improvement in in vivo insulin release per unit of energy compared to first-generation materials.
• Achieved efficient insulin release from injectable particles upon irradiation with a 406 nm light source.

Conclusions:

• Second-generation insulin PAD materials represent a significant advancement in light-activated drug delivery.
• The novel chemistry enables enhanced insulin release efficiency and improved light penetration for in vivo applications.
• These materials hold promise for more precise and effective insulin therapy in diabetes management.