Fabrication of polymer microneedles using a two-photon polymerization and micromolding process

Area of Science:

• Biomaterials Science
• Drug Delivery Systems
• Nanotechnology

Background:

• Microneedle technology shows potential for transdermal delivery of diabetes medications such as insulin.
• Conventional microneedles face limitations due to poor fracture resistance, hindering clinical use.
• This study introduces polymer microneedles fabricated using advanced microfabrication techniques.

Purpose of the Study:

• To develop and evaluate polymer microneedles for enhanced transdermal drug delivery.
• To address the mechanical limitations of existing microneedle technologies.
• To create a robust microneedle system for delivering protein-based therapeutics for diabetes.

Main Methods:

• Utilized two-photon polymerization (2PP) for microfabrication of microneedle molds.
• Employed polydimethylsiloxane (PDMS) micromolding to create negative molds.
• Fabricated eShell 200 polymer microneedle arrays using a photo-reactive, water-resistant acrylate-based polymer.

Main Results:

• The eShell 200 microneedle array exhibited adequate compressive strength for transdermal applications.
• Human epidermal keratinocyte viability on eShell 200 surfaces was comparable to polystyrene controls.
• In vitro tests confirmed successful penetration of human stratum corneum and epidermis by the microneedle arrays.

Conclusions:

• The 2PP microfabrication and PDMS micromolding process can yield microneedles with suitable properties for transdermal delivery.
• This method offers a viable approach for creating microneedle structures for diabetes treatment.
• The developed microneedles are suitable for delivering insulin and other protein-based drugs transdermally.