Insights into the writing process of the mask-free nanoprinting fluid force microscopy technology

Platelets are activated immediately when contacting with non-physiological surfaces.
Minimization of surface-induced platelet activation is important not only for platelet storage but
also for other blood-contacting devices and implants. Chemical surface modification tunes the
response of cells to contacting surfaces, but it requires a long process involving many regulatory
challenges to transfer into a marketable product. Biophysical modification overcomes these
limitations by modifying only the surface topography of already approved materials. The
available large and random structures on platelet storage bags do not cause a significant impact
on platelets because of their smallest size (only 1–3 μm) compared to other cells. We have
recently demonstrated the feasibility of the mask-free nanoprint fluid force microscope
(FluidFM) technology for writing dot-grid and hexanol structures. Here, we demonstrated that
the technique allows the fabrication of nanostructures of varying features including grid, circle,
triangle, and Pacman-like structures. Characteristics of nanostructures including height, width,
and cross-line were analyzed and compared using atomic force microscopy imaging. ... mehrBased on
the results, we identified several technical issues, such as the printing direction and shape of
structures that directly altered nanofeatures during printing. Importantly, both geometry and
interspace governed the degree of platelet adhesion, especially, the structures with triangular
shapes and small interspaces prevent platelet adhesion better than others. We confirmed that
FluidFM is a powerful technique to precisely fabricate a variety of desired nanostructures for
the development of platelet/blood-contacting devices if technical issues during printing are well
controlled.