Effect of Core‐Crosslinking on Protein Corona Formation on Polymeric Micelles

Abstract

Most nanomaterials acquire a protein corona upon contact with biological fluids. The magnitude of this effect is strongly dependent both on surface and structure of the nanoparticle. To define the contribution of the internal nanoparticle structure, protein corona formation of block copolymer micelles with poly(N‐2‐hydroxypropylmethacrylamide) (pHPMA) as hydrophilic shell, which are crosslinked—or not—in the hydrophobic core is comparatively analyzed. Both types of micelles are incubated with human blood plasma and separated by asymmetrical flow field‐flow fractionation (AF4). Their size is determined by dynamic light scattering and proteins within the micellar fraction are characterized by gel electrophoresis and quantified by liquid chromatography‐high‐resolution mass spectrometry‐based label‐free quantitative proteomics. The analyses reveal only very low amounts of plasma proteins associated with the micelles. Notably, no significant enrichment of plasma proteins is detectable for core‐crosslinked micelles, while noncrosslinked micelles show a significant enrichment of plasma proteins, indicative of protein corona formation. The results indicate that preventing the reorganization of micelles (equilibrium with unimers) by core‐crosslinking is crucial to reduce the interaction with plasma proteins.

Squaric Ester‐Based Nanogels Induce No Distinct Protein Corona but Entrap Plasma Proteins into their Porous Hydrogel Network

“…Measurements were recorded after 1 h incubation time at 37 °C ( Figure ). As shown earlier, 1 h of incubation is usually a sufficient time for the formation of a protein corona, [ 3 ] and follows previous protocols by Alberg and co‐workers [ 12,18 ] who further investigated the potential formation of a protein corona for other non‐colloidal polymeric nanocarriers. The black dots in the upper graphs show the autocorrelation function of the nanogel/plasma mixture at scattering angles of 30°, 50°, or 70°, while the fit of the sum of the individual components is represented by the red line, and the blue line displays the fit including an additional aggregation function if required.…”

“…Subsequently, the corresponding proteins were identified and labelfreely quantified by data processing and database search, as described recently. [12,27] In analogy to previous proteomic analyses of nanocarriers using this method, [12,18] comparison of the AF4 fraction of the plasma incubated nanocarrier with the fractions of the plasma as well as the nanocarrier control were used to identify those proteins that got enriched by the presence of the nanogel. By this means, proteins which are simply co-eluting contaminants resulting from nanocarrier fabrication or co-eluting free plasma proteins could be excluded.…”

“…[13,14] While so far mainly the protein corona of colloidal particles, [15][16][17] that are easily isolated by centrifugation, had been studied, Alberg et al investigated first non-colloidal polymer nanocarriers by means of their established AF4 LC-MS method. [12,18] Due to the low density of these non-colloidal polymeric nanocarriers, which is comparable to plasma/water, their isolation by centrifugation would not have been feasible. The studied nanocarriers were either polymeric brushes or crosslinked polymeric micelles consisting of a dense hydrophobic core, whose surface is coated and intrinsically stabilized by fully hydrated, hydrophilic "stealth" polymers according to the Whitesides' rules.…”

Targeting Cancer Chemotherapy Resistance by Precision Medicine-Driven Nanoparticle-Formulated Cisplatin

“…It is accepted that, when NPs enter (patho)­physiological environments, proteins and other biomolecules bind to the nanomaterial surface, leading to the rapid formation of a biomolecule corona. The corona may be critically codefining the biological, medical, biotechnological, and pathophysiological identity of NPs, although the mechanistic details have not been resolved in detail. − As the impact of the corona can still not be predicted reliably, the design of NPs with low biomolecule adsorption properties is desirable and can be achieved by several chemical functionalization strategies. , Here, the use of polypept­(o)­ide-based formulations promise good colloidal stability, biocompatibility (low immunogenicity, low toxicity, prolonged in vivo circulation, no complement activation, no plasma protein aggregation), and low corona formation properties. Polypept­(o)­ides are hybrid copolymers combining polypeptides with the polypeptoid polysarcosine (pSar, poly­( N -methyl glycine)), which is biologically well-tolerated. , pSar is considered a promising alternative to poly­(ethylene glycol), showing advantages of reduced proinflammatory cytokine secretion, reduced complement activation, and evasion of the accelerated blood clearance (ABC) phenomenon. − …”

“…24−30 As the impact of the corona can still not be predicted reliably, the design of NPs with low biomolecule adsorption properties is desirable and can be achieved by several chemical functionalization strategies. 31,32 Here, the use of polypept(o)ide-based formulations promise good colloidal stability, biocompatibility (low immunogenicity, low toxicity, prolonged in vivo circulation, no complement activation, no plasma protein aggregation), and low corona formation properties. Polypept-(o)ides are hybrid copolymers combining polypeptides with the polypeptoid polysarcosine (pSar, poly(N-methyl glycine)), which is biologically well-tolerated.…”