Fabricating High-Resolution and High-Dimensional Microneedle Mold through the Resolution Improvement of...

Area of Science:

• Biomaterials Engineering
• Additive Manufacturing
• Drug Delivery Systems

Background:

• Stereolithography (SLA) 3D printing offers rapid, cost-effective fabrication of microneedles for transdermal drug delivery.
• A key limitation of SLA is reduced resolution in precise microneedle printing.
• Optimizing printing parameters is crucial for high-fidelity microneedle production.

Purpose of the Study:

• To optimize SLA 3D printing conditions for high-resolution microneedle fabrication.
• To investigate the impact of printing angle, needle height, aspect ratio, and spacing on microneedle tip sharpness.
• To demonstrate the fabrication of advanced microneedle designs and their ex vivo skin penetration.

Main Methods:

• Systematic optimization of SLA 3D printing parameters, focusing on printing angle (x and y axes).
• Fabrication of microneedles with controlled dimensions (height, base, tip diameter).
• Ex vivo testing of dissolving microneedle patches on porcine skin.

Main Results:

• A printing angle of 60° in both x and y axes yielded the sharpest microneedle tips.
• Optimal conditions produced microneedles with a height of 1180 ± 20 µm, base of 490 ± 20 µm, and tip diameter of 30.2 ± 3.4 µm.
• Dissolving microneedle patches fabricated using the optimized 3D printed molds successfully penetrated ex vivo porcine skin.

Conclusions:

• Adjusting the printing angle in SLA 3D printing is a critical factor for achieving high-resolution and high-dimensional microneedles.
• This optimized technique enables the fabrication of complex microneedle structures, such as side-notched arrowhead (SNA) designs.
• The developed high-resolution 3D printing technology holds significant potential for manufacturing advanced drug delivery tools and microdevices.