Micromachines (Aug 2022)

Evaluation of 3D Printability and Biocompatibility of Microfluidic Resin for Fabrication of Solid Microneedles

  • Atabak Ghanizadeh Tabriz,
  • Beatriz Viegas,
  • Michael Okereke,
  • Md Jasim Uddin,
  • Elena Arribas Lopez,
  • Nazanin Zand,
  • Medhavi Ranatunga,
  • Giulia Getti,
  • Dennis Douroumis

DOI
https://doi.org/10.3390/mi13091368
Journal volume & issue
Vol. 13, no. 9
p. 1368

Abstract

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In this study, we have employed Digital Light Processing (DLP) printing technology for the fabrication of solid microneedle (MN) arrays. Several arrays with various geometries, such as cones, three-sided pyramids and four-sided pyramids, with different height to aspect ratios of 1:1, 2:1 and 3:1, were printed. Post-processing curing optimizations showed that optimal mechanical properties of the photocurable resin were obtained at 40 °C and 60 min. Ex vivo skin studies showed that piercing forces, penetration depth and penetration width were affected by the MN geometry and height to aspect ratio. Cone-shaped MNs required lower applied forces to penetrate skin and showed higher penetration depth with increasing height to aspect ratio, followed by three-sided and four-sided printed arrays. Cytotoxicity studies presented 84% cell viability of human fibroblasts after 2.5 h, suggesting the very good biocompatibility of the photocurable resin. Overall, DLP demonstrated excellent printing capacity and high resolution for a variety of MN designs.

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