Comparison of Protein-Repellent Behavior of Linear versus Dendrimer-Structured Surface-Immobilized Polymers

Abstract

For many biomedical applications, material surfaces should not only prevent unspecific protein adsorption and bacterial attachment as in many other applications in the food, health, or marine industry, but they should also promote the adhesion of tissue cells. In order to take a first step toward the challenging development of protein and bacteria-repelling and cell-adhesion-promoting materials, polyamine and poly­(amido amine) surface coatings with terminal amine groups and varying structure (dendrimer, oligomer, polymer) were immobilized on model surfaces via silane chemistry. Physicochemical analysis showed that all modifications are hydrophilic (contact angles <60°) and possess similar surface free energies (SFEs, ∼46–54 mN/m), whereas their amine group densities and zeta potentials at physiological conditions (pH 7.4) varied greatly (−50 to +75 mV). In protein adsorption experiments with single proteins (human serum albumin (HSA) and lysozyme) as well as complex physiological fluids (fetal bovine serum (FBS) and human saliva), the amounts of adsorbed protein were found to correlate strongly with the zeta potential of the surface coatings. Both modifications based on linear polymers exhibited good protein repellency toward all proteins examined and are thus promising for testing in cell adhesion studies.

Enhancement of Intracellular Calcium Ion Mobilization by Moderately but Not Highly Positive Material Surface Charges

“…The adverse effects of highly positive surface charges deduced from the ζ-potential might also be indirectly linked to protein adsorption, since it has been published that the protein adsorption is strongly affected by the ζ-potential (Krajewski et al, 1998;Lehnfeld et al, 2020) influencing the protein population (Shelton et al, 1988) and orientation (Norde and Lyklema, 1991;Antonini et al, 2014). Therefore, a further correlation between protein adsorption and ζ-potential of different surface modifications with well-defined effects on the cell behavior is of great interest.…”

In Situ Surface‐Initiated ATRP Mediated by Gallium‐Based Liquid Metal Nanodroplets

“…The zeta potential increased to 44.1 mV for PDMAEMA grafted GLM, which was due to the positive tertiary amine groups of PDMAEMA. [ 72 ] While the zeta potential of P(DMAEMA‐ b ‐SPMA) grafted GLM nanodroplets dropped to ‐32.2 mV due to the negative charged PSPMA (Figure 4b). In Figure 4c and Figure (Supporting Information), the newly appeared S signal at 167.6 eV in the XPS spectrum can be attributed to the characteristic sulfur element of PSPMA.…”