Multifunctional surface microrollers for targeted cargo delivery in physiological blood flow

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Materials Science

Background:

• Mobile microrobots show potential for targeted medical theranostics in hard-to-access body regions.
• Blood flow impedes microrobot propulsion, especially for those <10 micrometers.
• Effective cell/tissue targeting and preservation under dynamic flow are crucial.

Purpose of the Study:

• To develop cell-sized, leukocyte-inspired microrollers for targeted drug delivery and navigation in blood flow.
• To functionalize microrollers with cancer-targeting antibodies and light-cleavable drugs.
• To demonstrate controlled propulsion and targeting within physiological conditions.

Main Methods:

• Fabrication of ~3.0 and ~7.8-micrometer magnetically responsive Janus microparticle microrollers.
• Functionalization with anti-HER2 antibodies and doxorubicin.
• Magnetic propulsion/steering and testing in blood flow models (planar, endothelialized, 3D).

Main Results:

• Microrollers achieved propulsion speeds up to 600 µm/s (76 body lengths/s).
• Successful targeting of cancer cells within a heterogeneous population.
• Propulsion against physiologically relevant blood flow (up to 2.5 dynes/cm²) and on inclined 3D surfaces.

Conclusions:

• The leukocyte-inspired microroller platform enables controlled propulsion, navigation, and active cargo delivery in the circulatory system.
• This bioinspired approach advances in vivo theranostic capabilities.
• The microrollers demonstrate potential for minimally invasive cancer treatment.