Polymeric Microneedle Arrays with Glucose-Sensing Dynamic-Covalent Bonding for Insulin Delivery

Area of Science:

• Biomaterials Science
• Drug Delivery Systems
• Diabetes Therapeutics

Background:

• Rising diabetes incidence demands improved blood glucose control methods.
• Microneedle patches offer convenient transdermal therapeutic delivery.
• Existing in situ polymerization methods for microneedle fabrication risk toxic precursor exposure.

Purpose of the Study:

• To develop a novel polymeric microneedle patch using dynamic-covalent crosslinking.
• To create a microneedle system that integrates glucose sensing with insulin delivery.
• To circumvent the toxicity issues associated with in situ polymerization in microneedle fabrication.

Main Methods:

• Fabrication of dynamic-covalent hydrogel networks using phenylboronic acid (PBA)-diol bonds.
• Utilizing shear-thinning and self-healing properties of hydrogels for microneedle mold loading via centrifugation.
• Drying the loaded hydrogels to form skin-penetrating microneedle arrays.

Main Results:

• The fabricated microneedle patches possess suitable mechanical properties for skin penetration.
• Insulin release from the microneedles is shown to be glucose-responsive, accelerating in the presence of glucose.
• Short-term in vivo studies in a diabetic rat model demonstrated effective blood glucose control, confirming insulin activity and bioavailability.

Conclusions:

• Dynamic-covalent crosslinking provides a safe and effective alternative to in situ polymerization for microneedle array fabrication.
• The developed microneedle patch offers a convenient form factor for transdermal insulin delivery.
• This approach facilitates precise glucose control and circumvents toxicity concerns, advancing diabetes therapeutic strategies.