3D nanoprinting of embryo microinjection needles with anti-clogging features

Area of Science:

• Biomedical Engineering
• Microfabrication
• Developmental Biology

Background:

• Microinjection is crucial for biomedical applications, but conventional microneedles often clog.
• Clogging obstructs substance delivery into biological targets like embryos.
• Existing top-down microfabrication methods have limitations in addressing microneedle clogging.

Purpose of the Study:

• To investigate the potential of Two-Photon Direct Laser Writing (DLW) for fabricating clog-resistant microneedles.
• To design and test 3D-printed microneedles with specific architectural features to prevent clogging.
• To evaluate the enhanced delivery performance of these novel microneedles in biological models.

Main Methods:

• Utilized Two-Photon Direct Laser Writing (DLW) to 3D print hollow microneedles.
• Incorporated clog-reducing features: fine-point tip, side ports, and an internal microfilter.
• Conducted serial microinjection experiments using live zebrafish embryos.

Main Results:

• The 3D-printed microneedles exhibited significantly enhanced delivery performance compared to controls.
• No instances of complete blockage were observed with the novel microneedles.
• Standard glass and control 3D-printed microneedles experienced pervasive clogging.

Conclusions:

• DLW-based 3D printing offers a promising bottom-up approach for advanced microneedle fabrication.
• The designed microneedles effectively remediate clogging issues, improving microinjection reliability.
• These findings support the use of DLW-printed microneedles for high-precision applications, especially serial injections.