Nanostructured surfaces of biodegradable silica fibers enhance directed amoeboid cell migration in a microtubule-dependent process

Abstract

Cell motion and in particular amoeboid migration is crucial for the survival of living organisms. To advance biomedical research, a constant need for novel materials and surface structures arises, improving immigration of cells into artificial structures used for tissue engineering and for advancing therapy in modern medicine. This work focuses on investigating amoeboid single-cell migration on intrinsically nano-structured, biodegradable silica fibers in comparison to chemically equivalent plain glass surfaces. Cell migration trajectories are classified into directed runs and quasi-random migration by a local mean squared displacement (LMSD) analysis. We find that directed movement on silica fibers is enhanced in a significant manner by the fibers' nanoscale surface-patterns. Further, cell adhesion on the silica fibers is a microtubule-mediated process. Cells lacking microtubules detach from the fibers, but adhere well to glass surfaces. Knock-out mutants of myosin II migrating on the fibers are as active as cells with active myosin II, while the migration of the knock-out mutants is hindered on plain glass. Identifying relevant cytoskeletal compounds for cell migration in 2D vs. 3D will help to optimize materials or surfaces that boost specific migration strategies to open up new opportunities for innovative diagnostic and therapeutic concepts

Mesoscale substrate curvature overrules nanoscale contact guidance to direct bone marrow stromal cell migration

“…The cellular response to nano/micrometre-sized fibres, grooves, pillars and contact-printed lines has been well documented, demonstrating the role of contact guidance and topographical guidance by nano-and microscale geometrical features in cell migration [6,[16][17][18][19][20][21][22][23][24][25]. Moreover, there is a growing body of evidence that cells can also respond to geometrical cues equal or even larger than cell size [26][27][28][29][30].…”

Modulation of Mammalian Cell Behavior by Nanoporous Glass

“…While proliferation is highly diminished or even stopped on all samples, a high number of cells detaches from nanoporous samples while cells on FLAT samples remain adherent. In a recently published study, we found that the microtubule‐diminishing drug Benomyl has a similar effect on the adhesion of amoeboid cells of Dictyostelium discoideum to nanostructured SiO 2 fibers: Upon drug treatment, almost all of the cells deadhere from the nanostructured fibers, adhesion to flat glass is persisting. [ 45 ] These findings indicate a suitability of these nanoporous substrates for the quick detection of active substances that interfere with cytoskeletal and adhesion processes. This or similar effects found in future studies could be fostered for clinical application, e.g., in personalized cancer treatments to see if a specific patient's cancer cells respond differently to a set of potential drugs or drug combinations.…”

“…Proliferation Experiments: Prior to the experiments, nanoporous glass membranes with four different mean pore sizes (17,45,81, and 124 nm) and FLAT glass reference samples were glued to glass sample holders for upside-down culture and autoclaved. The glasses and TCPS reference surfaces were pre-incubated with phosphate buffered saline (PBS, Sigma-Aldrich) for 15 min and culture medium for 30 min.…”

“…To elucidate cell behavior on nanoporous glass membranes, we analyzed the proliferation of L929 cells under standard cell culture conditions. For this purpose, cells were seeded onto nanoporous glass membranes with four different mean pore sizes (17,45,81, and 124 nm) and two flat reference surfaces (FLAT/TCPS). Microscopy and cell counting was performed for days 1, 2, 3, 4, 6, 7, and 10 after cell seeding (Figure 2a).…”

Freeform direct laser writing of versatile topological 3D scaffolds enabled by intrinsic support hydrogel

“…In the natural ECM, this is enabled by the loosely intertwined, yet mechanically strong, densely packed extracellular matrix proteins. Since cells are capable of sensing this environment with submicron resolution, 7 and are highly influenced by the 2D and 3D morphology of the substrate, 8,9 a scaffold fabrication technique with corresponding submicron resolution is needed. Several rapid prototyping methods were established within recent years for the generation of 3D scaffolds for cell support.…”