Understanding the Lipid and Protein Corona Formation on Different Sized Polymeric Nanoparticles

Abstract

When in contact with biological fluids, nanoparticles dynamically absorb biomolecules like proteins and lipids onto their surface, forming a "corona". This biocorona is a dynamic and complex structure that determines how host cells respond to nanoparticles. Despite the common use of mouse models in pre-clinical and toxicological experiments, the impact of corona formed in mouse serum on the biophysical and biological properties of different size NP has not been thoroughly explored. Furthering the knowledge on the corona formed on NP exposed to mouse serum proteins can help in understanding what role it might have in in vivo studies at systemic, tissue, and cellular levels. To investigate biocorona formation, different sized polystyrene NP were exposed to mouse serum. Our data show a size- and time-dependent protein and lipid corona formation. Several proteins were identified and apolipoproteins were by far the most common group on the NPs surfaces. Moreover, we observed that cholesterol and triglycerides effectively bind to NP emphasizing that proteins are not the only biomolecules with high-affinity binding to nanomaterial surfaces. These results highlight that further knowledge on NP interactions with mouse serum is necessary regarding the common use of this model to predict the in vivo efficiency of NP.

Figure 1

Size distribution of COOH-PS nanoparticles in PBS (black) and MS (blue). Mean by DCS. Measurements were performed by DCS in PBS and 1 h after MS incubation.

Figure 2

Size dependence differences in protein corona of COOH-PS NPs after MS incubation. NPs (200 nm, 80 nm, 26 nm) were incubated at 0,5 mg ml⁻¹ (mass normalized samples) with MS during 1 h, 12 h and 24 h. NP were separated from free proteins by centrifugation and proteins adsorbed to COOH-PS NP was resolved by 10% SDS-Page gel and stained with Coomassie. Full length gel is presented in Supplementary Fig. 6.

Figure 3

Size-dependent differences around COOH-PS NP by SDS-page gel. 200 nm, 80 nm and 26 nm COOH-PS NPs were incubated with MS at 0,5 mg ml⁻¹ or for 1 h at 37 °C. The protein corona was resolved by 10% acrylamide SDS-page gel and a densitometry analysis using Image J/FIJI. A- Myosin-9, B- Clusterin, C- APO E, D- APO A-I. Full lenght gels are presented in Supplementary Figs. 7 and 8.

Figure 4

Venn diagram representing the distribution of proteins found to associate with COOH-PS NP following incubation with MS.

Figure 5

Lipid quantification on COOH-PS NP after MS incubation. Levels of triglycerides and cholesterol in the corona were quantified after 1 h and 24 h incubation with MS in COOH-PS NPs normalized to 5 × 10¹⁰ μm² surface area. (A) Overtime comparison between 200 nm and 80 nm lipid corona. (B) Each condition was set in triplicate. Bars correspond to means plus SD. One-way ANOVA with Bonferroni post Hoc test. (*P < 0,05; **P < 0,01; ****P < 0,0001).