Comparison of PEI‐PEG and PLL‐PEG copolymer coatings on the prevention of protein fouling

Abstract

The effect of surface charge on the protein resistance of adsorbed layers of poly(ethylene imine)-[g]-poly(ethylene glycol), PEI-PEG, and poly(L-lysine)-[g]-poly(ethylene glycol), PLL-PEG, was studied. Mixed and monofunctional self-assembled monolayers, SAMs, on gold were obtained by adsorption of 16-mercapto-1-hexadecanoic acid and 16-mercapto-1-hexadecanol. The surface charge was systematically varied by changing the ratio of the two alkanethiols. The graft copolymers PEI-PEG and PLL-PEG were adsorbed at the SAMs and tested for resistance towards human serum albumin and fibrinogen. The adsorbed amount of copolymers increased with increasing negative surface charge. However, the best protein resistance was found at an intermediate surface charge. The PLL-PEG covered surfaces showed better protein resistance than the PEI-PEG covered surfaces. Thus, this work demonstrates that an adsorbed layer of PEG-grafted PEI and, in particular, PEG-grafted PLL is efficient in preventing protein adsorption when there is charge neutralization between the copolymer and the underlying surface.

Functionalization of Cationic Polymers for Drug Delivery Applications

“…57 The introduction of an artery wall-binding peptide to the PLL-b-PEG copolymer led to a specific targeting and drastically increased the transfection efficiency by 18 000% compared to the PLL-b-PEG copolymer without the covalently bound peptide. 58,59 Similar targeting properties were achieved by introducing a leukaemia-specific JL1 antigen to the PLL backbone. 60 PLL dendrimers and their PEGylated derivatives, including a pH-sensitive linker molecule for the release of the drug, have been prepared and applied for drug delivery purposes.…”

Surface characteristics of poly(γ‐alkyl α l‐glutamate)s with different alkyl groups

“…Testing temperature was rigorously controlled at 25.0 ± 0.1°C throughout the experiment. The amount of adsorbed protein was calculated from the following equation: where Δ m is the mass of adsorbed protein, Δ RU is the response unit from SPR and C spr is a proportionality constant, which has been calibrated to ∼ 0.066 ng/cm 2 for protein adsorption 26, 27…”

“…where Dm is the mass of adsorbed protein, DRU is the response unit from SPR and C spr is a proportionality constant, which has been calibrated to $ 0.066 ng/cm 2 for protein adsorption. 26,27…”

Poly(dopamine)-assisted preparation of star poly(ethylene glycol)-based coatings: A detailed study of their protein resistance and application in CE

“…bPEI can thus be employed as scaffolds for the fabrication of hyperbranched or multiarm star polymeric structures [29,30]. For example, linear PEGs have been grafted onto bPEI chains to obtain the multiarm star shaped copolymers which can be used as carriers for gene delivery [31], and the copolymers have also shown excellent prevention of non-specific protein adsorption [32]. Reactive and Functional Polymers xxx (2015) xxx-xxx Numerous strategies existed for surface PEGylation have been proposed based on polyelectrolytes on charged surfaces [33], thiolate on noble metals [34], alkylsilane on silicon (dioxide) [35], phosphonic acid on titanium oxides [36], and so on.…”