Analysis of plasma protein adsorption onto PEGylated nanoparticles by complementary methods: 2‐DE, CE and Protein Lab‐on‐chip® system

Abstract

The biodistribution of colloidal carriers after their administration in vivo depends on the adsorption of some plasma proteins and apolipoproteins on their surface. Poly(methoxypolyethyleneglycol cyanoacrylate-co-hexadecylcyanoacrylate) (PEG-PHDCA) nanoparticles have demonstrated their capacity to cross the blood-brain barrier (BBB) by a mechanism of endocytosis. In order to clarify this mechanism at the molecular level, proteins and especially apolipoproteins adsorbed at the surface of PEG-PHDCA nanoparticles were analyzed by complementary methods such as CE and Protein Lab-on-chip in comparison with 2-D PAGE as a method of reference. Thus, the ability of those methodologies to identify and quantify human and rat plasma protein adsorption onto PEG-PHDCA nanoparticles and conventional PHDCA nanoparticles was evaluated. The lower adsorption of proteins onto PEG-PHDCA nanoparticles comparatively to PHDCA nanoparticles was evidenced by 2-D PAGE and Protein Lab-on-chip methods. CE allowed the quantification of adsorbed proteins without the requirement of a desorption procedure but failed, in this context, to analyze complex mixtures of proteins. The Protein Lab-on-chip method appeared to be very useful to follow the kinetic of protein adsorption from serum onto nanoparticles; it was complementary to 2-D PAGE which allowed the identification (with a relative quantification) of the adsorbed proteins. The overall results suggest the implication of the apolipoprotein E in the mechanism of passage of PEG-PHDCA nanoparticles through the BBB.

Biomolecular coronas provide the biological identity of nanosized materials

“…Small hydrophobic molecules, loosely speaking, partition in biological compartments according to physicochemical equilibrium principles 46 , while larger micron-sized objects engage significantly with macrophages and other elements of the front-line immune system 29 . In contrast, because of their size and surface, nanoparticle-corona complexes can engage with a wide range of endogenous cellular uptake and other processes, and potentially reach all cellular and organ compartments [27][28][29]35 , interact with them, and initiate signalling processes 10 . Endocytic mechanisms of cellular uptake are known from the extensive biomolecular transport literature 43,47 .…”

“…While surface modifications (such as PEGylation 39 ) reduce the binding of additional biomolecules, some association of biomolecules may still occur 35,40 . Their presence may lead to more subtle and poorly understood biological consequences, issues possibly related to current struggles in achieving efficient targeting of nanomedicines in vivo.…”

“…There have also been suggestions that surface biomolecules (including adsorbed endogenous proteins) could influence the crossing of biological barriers, such as the blood-brain barrier 35,58,59 . Mastering these phenomena will have deep implications for both nanosafety and nanotherapeutics 4 .…”

The design and utility of polymer-stabilized iron-oxide nanoparticles for nanomedicine applications

“…One of the most effi cient polymers employed in preventing protein binding on surfaces is PEG, which has been used to limit interactions between proteins and nanoparticles surfaces [54]. There are two significant factors that are known to influence the efficiency of PEGamelioration of protein binding to surfaces: molecular weight and grafting density.…”

Cysteine‐capped gold nanoparticles suppress aggregation of proteins exposed to heat stress

“…Furthermore, the degree of the structural perturbation that proteins undergo in response to their interaction with particular nanoparticles varies across protein species. The complete plasma proteome is composed of approximately 3700 different proteins and about 50 of these have been shown to associate with nanoparticles (6,7). Therefore, there are concerns regarding the safety of nanoparticles and whether modifications that biological materials undergo upon their interaction with nanoparticles may alter their intended function (8).…”