Protein- and Cell-Resistance of Zwitterionic Peptide-Based Self-Assembled Monolayers: Anti-Biofouling Tests and Surface Force Analysis

Abstract

Peptide-based self-assembled monolayers (peptide-SAMs) with specific zwitterionic amino acid sequences express an anti-biofouling property. In this work, we performed protein adsorption and cell adhesion tests using peptide-SAMs with repeating units of various zwitterionic pairs of amino acids (EK, DK, ER, and DR). The SAMs with the repeating units of EK and DK (EK and DK SAMs) manifested excellent bioinertness, whereas the SAMs with the repeating units of ER and DR (ER and DR SAMs) adhered proteins and cells. We also performed surface force measurements using atomic force microscopy to elucidate the mechanism underlying the difference in the anti-biofouling property. Our measurements revealed that water-induced repulsion with a range of about 8 nm acts between EK SAMs (immobilized on both probe and substrate) and DK SAMs, whereas such repulsion was not observed for ER and DR SAMs. The strength of the repulsion exhibited a clear correlation with the protein- and cell-resistance of the SAMs, indicating that the interfacial water in the vicinity of EK and DK SAMs is considered as a physical barrier to deter protein and cells from their adsorption or adhesion. The range of the repulsion observed for EK and DK SAMs is longer than 8 nm, indicating that the hydrogen bonding state of the interfacial water with a thickness of 4 nm is modified by EK and DK SAMs, resulting in the expression of the anti-biofouling property.

Prediction of Serum Adsorption onto Polymer Brush Films by Machine Learning

“…due to simple synthesis, well-defined monolayer structure, and a large diversity of surface chemistry (polarity, surface charge, etc.) by simply altering the terminal group. − Thus far, the water molecule’s interaction at the monolayer’s interfaces has been expected to play an essential role in the antibiofouling properties of SAMs as the underlying mechanism in antibiofouling. ,,− However, the quantitative prediction of protein adsorption onto SAMs is still difficult, as many kinds of forces with different physical origins are involved in the protein–SAM interactions. These interactions cannot be accurately estimated by theoretical calculations (e.g., DLVO theory) or molecular simulations. ,− Therefore, it is still challenging to design antibiofouling SAMs based on the previous findings.…”

Design of biomaterials through direct ring-opening metathesis polymerisation of functionalised cyclic alkenes

“…94 The hydration state and biocompatibility of these polymers can be tuned by controlling the side chain spacing 94,114,139–141 and changing the chemical structure of the side chains. 142–167…”

Bioactive Coatings on Titanium: A Review on Hydroxylation, Self-Assembled Monolayers (SAMs) and Surface Modification Strategies

“…The properties of the solid surfaces, including their physical, chemical, electric, bioactivity and optical properties can be modulated by incorporating the specific terminal end group of the SAMs [ 70 ]. Consequently, this type of surfaces has shown wide applicability in very different fields such as molecular sensors [ 71 ], electrochemical sensing [ 72 , 73 ] biosensors [ 74 , 75 ], preventive anti-biofouling surfaces [ 76 ], organic electronics [ 77 , 78 ] and tribological applications [ 79 ], among others.…”