Functionalizable Antifouling Coatings as Tunable Platforms for the Stress-Driven Manipulation of Living Cell Machinery

Abstract

Cells are continuously sensing their microenvironment and subsequently respond to different physicochemical cues by the activation or inhibition of different signaling pathways. To study a very complex cellular response, it is necessary to diminish background environmental influences and highlight the particular event. However, surface-driven nonspecific interactions of the abundant biomolecules from the environment influence the targeted cell response significantly. Yes-associated protein (YAP) translocation may serve as a marker of human hepatocellular carcinoma (Huh7) cell responses to the extracellular matrix and surface-mediated stresses. Here, we propose a platform of tunable functionable antifouling poly(carboxybetain) (pCB)-based brushes to achieve a molecularly clean background for studying arginine, glycine, and aspartic acid (RGD)-induced YAP-connected mechanotransduction. Using two different sets of RGD-functionalized zwitterionic antifouling coatings with varying compositions of the antifouling layer, a clear correlation of YAP distribution with RGD functionalization concentrations was observed. On the other hand, commonly used surface passivation by the oligo(ethylene glycol)-based self-assembled monolayer (SAM) shows no potential to induce dependency of the YAP distribution on RGD concentrations. The results indicate that the antifouling background is a crucial component of surface-based cellular response studies, and pCB-based zwitterionic antifouling brush architectures may serve as a potential next-generation easily functionable surface platform for the monitoring and quantification of cellular processes.

Biorecognition antifouling coatings in complex biological fluids: a review of functionalization aspects

“…, affibodies) 46,155–158 or other specific functions, such as antimicrobial effects, 159,160 or cell adhesion promotion. 161 Peptides are easily tunable and stable, however, the affinity typically does not achieve the affinity of antibodies.…”

“…150,151 Among protein-based BEs, non-antibody based short peptides can be easily tailored to carry intended properties, such as fouling resistance, 47,[152][153][154] biorecognition (e.g., affibodies) 46,[155][156][157][158] or other specific functions, such as antimicrobial effects, 159,160 or cell adhesion promotion. 161 Peptides are easily tunable and stable, however, the affinity typically does not achieve the affinity of antibodies.…”

Polymer brush structures functionalized with molecular beacon for point-of-care diagnostics

“…Synthetic polymer-brush coatings offer an alternative approach to blocking buffers [18][19][20]. They may eliminate Non-Specific Binding (NSB) in real clinical samples and therefore increase the singnal to noise ratio (SNR), improving the assay's Limit of Detection (LOD) and reducing the need for complex signal amplification [21][22][23].…”

Tuning of Surface Charge of Functionalized Poly(Carboxybetaine) Brushes Can Significantly Improve Label‐Free Biosensing in Complex Media

“…[ 1–8 ] Besides the resistance to fouling, the platform should be easily functionalized, i.e., conjugated with molecules having specific biological activity, usually a high affinity for specific targets. [ 9–16 ] Applications that require such functionalized antifouling platforms span from rapid detection of chemical and biological species, coatings of nanoparticles used in drug delivery, membranes for separation and cleaning technologies, to scaffolds for tissue engineering.…”

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Besides the resistance to fouling, the platform should be easily functionalized, i.e., conjugated with molecules having specific biological activity, usually a high affinity for specific targets. [9][10][11][12][13][14][15][16] Applications that require such functionalized antifouling platforms span from rapid detection of chemical and biological species, coatings of nanoparticles used in drug delivery, membranes for separation and cleaning technologies, to scaffolds for tissue engineering.Poly(carboxybetaine) (pCB) brushes are outstanding antifouling platforms allowing facile functionalization with biorecognition elements (BREs) via EDC/NHS (carbodiimide/N-hydroxysuccinimide) chemistry. [17][18][19] Their extraordinary properties stem from their high hydrophilicity and overall electroneutrality, which makes them resistant to hydrophobic as well as electrostatic adsorption from contacted media.

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