Self-Adhesive Microneedles with Interlocking Features for Sustained Ocular Drug Delivery

Area of Science:

• Biomaterials Science
• Ophthalmology
• Drug Delivery Systems

Background:

• Sustained ocular drug delivery aims to improve patient compliance and therapeutic outcomes by reducing the need for frequent intravitreal injections.
• Microneedles (MNs) present a minimally invasive approach for ocular drug delivery, but securing MN patches in the eye remains a significant challenge.

Purpose of the Study:

• To develop and evaluate novel hydrogel microneedles (MNs) with integrated interlocking features for enhanced self-adhesion in ocular applications.
• To investigate a new fabrication process for creating MNs with complex interlocking geometries.

Main Methods:

• Fabrication of polyvinyl alcohol (PVA) hydrogel MNs with two distinct interlocking feature designs using a novel molding process.
• Evaluation of MN adhesion strength and penetration force using a sclera-mimicking phantom and ex vivo rabbit eyes.
• Comparison of performance between MNs with and without interlocking features.

Main Results:

• MNs incorporating interlocking features demonstrated an 80% increase in adhesion strength compared to standard MNs.
• A marginal increase in penetration force was observed with the interlocking features.
• Experimental results from phantom and ex vivo models showed comparable performance, validating the design's efficacy.

Conclusions:

• The proposed hydrogel MNs with interlocking features offer a promising solution for self-adhesion in ocular drug delivery systems.
• This design innovation facilitates secure MN patch placement, enabling effective sustained drug delivery and potentially overcoming limitations of current methods.