3D-Printed Biodegradable Microswimmer for Theranostic Cargo Delivery and Release

Area of Science:

• Biomedical Engineering
• Materials Science
• Nanotechnology

Background:

• Untethered mobile microrobots offer potential for minimally invasive theranostics in confined bodily sites.
• Integrated design considering power, control, sensing, medical function, and biodegradability is crucial for microrobot development.

Purpose of the Study:

• To report a hydrogel-based, magnetically powered and controlled, enzymatically degradable microswimmer.
• To enable responsive theranostic cargo delivery and release in pathological microenvironments.

Main Methods:

• A double-helical architecture was designed for volumetric cargo loading and magnetic field-driven swimming.
• A 3D microswimmer was fabricated using two-photon polymerization with gelatin methacryloyl and superparamagnetic iron oxide nanoparticles.
• Enzymatic degradation by matrix metalloproteinase-2 (MMP-2) and cargo release mechanisms were investigated.

Main Results:

• The microswimmer, approximately 20 μm long, is fully degraded by MMP-2 within 118 hours into non-toxic products.
• Microswimmers exhibit a responsive swelling behavior to pathological MMP-2 concentrations, enhancing cargo release.
• Demonstrated release of therapeutic molecules and anti-ErbB 2 antibody-tagged magnetic nanoparticles for cancer cell labeling.

Conclusions:

• The developed microswimmer is magnetically controlled, enzymatically degradable, and responsive to pathological markers for theranostic applications.
• This technology holds promise for targeted drug delivery, in vitro diagnostics, and potential future medical imaging applications.