Abstract:We present a facile technique for the gray-scale chemical functionalization of polymer surfaces with high dynamic range. We demonstrate the use of this technique to create amine-functionalized substrates that are used for the patterned binding of fluorophores and the patterned synthesis of peptides. Studies of the behavior of the model organism Dictyostelium discoideum indicate the biocompatibility of the functionalized substrates.
“…We functionalized the nanoridges with collagen IV to render the surfaces adherent to mammalian cells such as MCF10A human breast epithelial cells and HL60 neutrophil-like cells. The exposed amine groups on collagen react naturally with surface acrylate groups through Michael addition 29 . To characterize the collagen coating, we treated the collagen-IV-coated nanoridges with NHS Alexa 594, which fluorescently labels the protein but not the acrylic polymer (Fig.…”
Section: Resultsmentioning
confidence: 99%
“…Any protein/peptide with surface amine and/or thiol groups is expected to exhibit good adhesion. The curing time of the replica can also be tuned to adjust the density of residual acrylate groups on the polymer surface available for the subsequent protein coating 29 . Figure 4 Functionalization of nanoridges with collagen IV.…”
The ability of cells to sense and respond to nanotopography is being implicated as a key element in many physiological processes such as cell differentiation, immune response, and wound healing, as well as in pathologies such as cancer metastasis. To understand how nanotopography affects cellular behaviors, new techniques are required for the mass production of biocompatible, rigid nanotopographic surfaces. Here we introduce a method for the rapid and reproducible production of biocompatible, rigid, acrylic nanotopographic surfaces, and for the functionalization of the surfaces with adhesion-promoting molecules for cell experiments. The replica surfaces exhibit high optical transparency, which is advantageous for high-resolution, live-cell imaging. As a representative application, we demonstrate that epithelial cells form focal adhesions on surfaces composed of nanoscale ridges and grooves, and that the focal adhesions prefer to localize on the nanoridges. We further demonstrate that both F-actin and microtubules align along the nanoridges, but only F-actin aligns along the nanogrooves. The mass production of nanotopographic surfaces opens the door to the investigation of the effect of physical cues on the spatial distribution and the dynamics of intracellular proteins, and to the study of the mechanism of mechanosensing in processes such as cell migration, phagocytosis, division, and differentiation.
“…We functionalized the nanoridges with collagen IV to render the surfaces adherent to mammalian cells such as MCF10A human breast epithelial cells and HL60 neutrophil-like cells. The exposed amine groups on collagen react naturally with surface acrylate groups through Michael addition 29 . To characterize the collagen coating, we treated the collagen-IV-coated nanoridges with NHS Alexa 594, which fluorescently labels the protein but not the acrylic polymer (Fig.…”
Section: Resultsmentioning
confidence: 99%
“…Any protein/peptide with surface amine and/or thiol groups is expected to exhibit good adhesion. The curing time of the replica can also be tuned to adjust the density of residual acrylate groups on the polymer surface available for the subsequent protein coating 29 . Figure 4 Functionalization of nanoridges with collagen IV.…”
The ability of cells to sense and respond to nanotopography is being implicated as a key element in many physiological processes such as cell differentiation, immune response, and wound healing, as well as in pathologies such as cancer metastasis. To understand how nanotopography affects cellular behaviors, new techniques are required for the mass production of biocompatible, rigid nanotopographic surfaces. Here we introduce a method for the rapid and reproducible production of biocompatible, rigid, acrylic nanotopographic surfaces, and for the functionalization of the surfaces with adhesion-promoting molecules for cell experiments. The replica surfaces exhibit high optical transparency, which is advantageous for high-resolution, live-cell imaging. As a representative application, we demonstrate that epithelial cells form focal adhesions on surfaces composed of nanoscale ridges and grooves, and that the focal adhesions prefer to localize on the nanoridges. We further demonstrate that both F-actin and microtubules align along the nanoridges, but only F-actin aligns along the nanogrooves. The mass production of nanotopographic surfaces opens the door to the investigation of the effect of physical cues on the spatial distribution and the dynamics of intracellular proteins, and to the study of the mechanism of mechanosensing in processes such as cell migration, phagocytosis, division, and differentiation.
We investigate the effects of surface nanotopography on the migration and cell shape dynamics of the amoeba Dictyostelium discoideum. Multiple prior studies have implicated the patterning of focal adhesions in contact guidance. However, we observe significant contact guidance of Dictyostelium along surfaces with nanoscale ridges or grooves, even though this organism lacks integrin-based adhesions. Cells that move parallel to nanoridges are faster, more protrusive at their fronts, and more elongated than are cells that move perpendicular to nanoridges. Quantitative studies show that nanoridges spaced 1.5 μm apart exhibit the greatest contact guidance efficiency. Because Dictyostelium cells exhibit oscillatory shape dynamics, we model contact guidance as a process in which stochastic cellular harmonic oscillators couple to the periodicity of the nanoridges. In support of this connection, we find that nanoridges nucleate actin polymerization waves of nanoscale width that propagate parallel to the nanoridges.
“…The monomers tris (2‐hydroxy ethyl) isocyanurate triacrylate (SR368 – Sartomer ® ) and dipentaerythritol pentaacrylate (SR399 – Sartomer ® ) were mixed in a proportion of 10/90 wt%. This prepolymer resin has been used previously, with some differences in the monomers proportion, for photonic and biological applications . Ethanol (2 mL) was added to the monomer composition to assist their dissolution.…”
Poly(para-phenylene vinylene) (PPV) is a key material for optoelectronics because it combines the potential of both polymers and semiconductors. PPV has been synthesized via solution-processable precursor route, in which the precursor polymer poly(xylene tetrahydrothiophenium chloride) (PTHT) is thermally converted to PPV throughout the sample as a whole. Much effort has been devoted to fulfill spatial selectivity of PPV conversion. However, none of the methods proposed stand for PPV conversion three dimensionally, which would be appealing for the design of microdevices. Here, we demonstrate the potential of fs-laser direct writing via two-photon polymerization (2PP) to fabricate PPV-doped 3D microstructures. PTHT is incorporated into the polymeric material and it is subsequently converted to PPV through a thermal treatment. Optical measurements, taken prior and after thermal conversion, confirm the PTHT to PPV conversion. Fs-laser direct writing via 2PP can be exploited to fabricate a variety of 3D microdevices, thus opening new avenues in polymer-based optoelectronics.
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