A surface plasmon resonance study of albumin adsorption to PEO-PPO-PEO triblock copolymers

Abstract

Pluronic surfactants, PEO-PPO-PEO triblock copolymers, have been investigated widely due to their protein-resistant properties in applications as coatings for implants and in controlled drug release systems. We have studied a wide range of these copolymers, varying in both PEO and PPO block size, by adsorbing them to a polystyrene surface and investigating their subsequent resistance to human serum albumin adsorption. This investigation has been carried out in real time, using surface plasmon resonance, with the surfaces subsequently visualized by atomic force microscopy. This approach has allowed determination of the effect of the lengths of the PEO and PPO polymer chains on protein resistivity. For low-molecular-weight Pluronics a significant, yet not complete, reduction in albumin adsorption has been observed whereas higher molecular weight Pluronics appear to completely inhibit adsorption within the time frame of this experiment. An increase in the PPO block size of the copolymer also appears to increase its protein resistance. This work further confirms that the binding strength of the anchoring block to the hydrophobic surface, rather than the length of the protruding hydrophilic PEO chains, determines a copolymer's protein resistance capability.

Poly(l-lysine)-grafted-poly(ethylene glycol)-based surface-chemical gradients. Preparation, characterization, and first applications

“…The protein resistance of PEG modified surfaces is attributed mainly to entropic repulsion and the high water content of the PEG chains. Among other methods, PEG chains may be immobilized on surfaces via covalent coupling, either by "grafting to" [16][17][18][19] or "grafting from," 20 via the adsorption of PEG-containing block copolymers, 18,[21][22][23] graft copolymers, 24,25 and interpenetrating polymer networks 26,27 and via functionalization with ethylene glycol-terminated alkanethiols 7,[28][29][30][31] or silanes. 32,33 For the platforms dealing with PEG in a brushlike conformation, it was found that the most important parameter determining the protein resistance is the ethylene glycol monomer density on the surface n EG expressed as EG units/surface unit.…”

Adsorption of a PEO–PPO–PEO triblock copolymer on metal oxide surfaces with a view to reducing protein adsorption and further biofouling

“…In contrast, PEO-PPO-PEO can form a pancake structure on hydrophilic surfaces (Schroen et al 1995), which is insufficient 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 (Chang et al 2010). The mechanism of protein resistance ability of PEO-PPO-PEO is attributed to the high hydration of PEO chains extending into the bulk solution, resulting in a steric barrier (Freij-Larsson et al 1996;Green et al 1998). (1997).…”

“…PEO-PPO-PEO (where PPO stands for poly(propylene oxide)) triblock copolymers, commercially available under the name of Pluronic ® , can also be used to form PEO-based polymer coatings through adsorption on hydrophobic surfaces (Freij-Larsson et al 1996), thereby reducing protein adsorption (Green et al 1998). Pluronic ® is commonly used as a non-ionic polymeric surfactant in chemical and pharmaceutical industries (Amiji & Park 1992;Green et al 1997).…”

Polyethylene Glycol Grafting on Polypropylene Membranes for Anti-fouling Properties

“…Many techniques have been used to prepare PEG surfaces for biomaterials applications. The simplest technique is the adsorption of Polyethylene-polypropylenepolyethylene (PEG/PPG/PEG) copolymers onto a hydrophobic substrate [5,6]. A problem of PEG surfaces prepared by a simple adsorption technique is their tendency of elution or competitive adsorption.…”