Fig. 6: Cyclic elevation of anisotropic nano-blockers escalates # ligand inter-cluster edges that reversibly stimulate integrin recruitment.

a Schematic illustration of the cyclic elevation (“E.”) and non-elevation (“NE.”) of high-anisotropy nano-blockers grafted to the materials (“High aniso.”) that can reversibly escalate # ligand inter-cluster edges. b In situ atomic force microscopy (AFM) images of the cyclic elevation of high-anisotropy nano-blockers for reversible tuning of # ligand inter-cluster edges repeated over two cycles marked with white dotted lines at the midsection for height analysis and c the subsequent computation of peak height changes of the nano-blockers (n = 5; ***p < 0.001). d Schematic illustration of utilizing L-cysteine to compute the number of polymer linkers coupled to the nano-blocker surfaces using Ellman’s assay for (e) computation of the reacted L-cysteine molarity on the anisotropic nano-blockers either coupled with a low (used in this study) or high density of polymer linker (n = 4; ***p < 0.001). f Scanning electron microscopy (SEM), elemental energy dispersive spectroscopy (EDS) mapping (Fe from the magnetite phase of the nano-blocker core), and overlay images of immuno-GNP (IGNP)-based tagging of integrin in stem cells adhered to the materials displaying tunable # ligand inter-cluster edges. g Schematic illustration and SEM images of the IGNP-tagged integrin in stem cells that could infiltrate through nano-gaps (at low polymer linker density showing the image in Fig. 5f) or were blocked (at high polymer linker density) when the anisotropic nano-blockers were elevated. h Computation of the average number of IGNP-tagged integrin in stem cells at the cell boundary per unit area (μm²) (n = 3 gold nanoparticles; **p < 0.01; ***p < 0.001) and inter-distance of the liganded GNPs after cell culturing (n = 10 edges). A piece of permanent magnet (295 mT) was employed (“E.”) or non-employment (“NE.”) above the materials for the cyclic elevation of high-anisotropy nano-blockers. High-anisotropy nano-blockers were linearized (“Lin.”) on the materials via magnetic annealing during their grafting to the material surface. In the SEM images, stem cells and IGNPs are each colored green and white, respectively. Scale bars: 200 nm (AFM) and 500 nm (SEM and EDS). Data are shown as the means ± standard errors. Statistical analysis was performed using one-way ANOVA along with the Tukey–Kramer post hoc test. N.S. denotes no statistically significant difference. Source data are provided as a Source Data file.