Triggered release of insulin from glucose-sensitive enzyme multilayer shells

Area of Science:

• Biomaterials Science
• Nanotechnology
• Drug Delivery Systems

Background:

• Insulin delivery systems require precise glucose responsiveness.
• Layer-by-layer (LbL) assembly offers a versatile platform for creating functional nanostructures.
• Controlled release of therapeutic proteins like insulin is a significant challenge.

Purpose of the Study:

• To develop a glucose-sensitive multilayer shell for insulin encapsulation and controlled release.
• To investigate the mechanism of glucose-induced insulin release from the fabricated core-shell system.
• To evaluate the potential of this system for advanced drug delivery applications.

Main Methods:

• Fabrication of a glucose-sensitive multilayer shell using layer-by-layer (LbL) assembly.
• Encapsulation of insulin within the multilayer structure.
• Assembly of glucose oxidase (GOD) and catalase (CAT) with glutaraldehyde (GA) cross-linking.
• Assessment of glucose-induced insulin release and microenvironment pH changes.

Main Results:

• The core-shell system demonstrated glucose sensitivity, with increased insulin release upon glucose introduction.
• Glucose catalysis by GOD/CAT shells led to H+ production, lowering the microenvironment pH.
• Acidic conditions promoted insulin release by breaking Schiff base bonds and increasing insulin solubility.

Conclusions:

• The developed CAT/GOD multilayer shell is a promising glucose-sensitive carrier for insulin delivery.
• The system's pH-dependent release mechanism offers a novel approach for controlled drug release.
• LbL capsules show significant potential for future applications in drug delivery and controlled release technologies.