Proteomic and Lipidomic Analysis of Nanoparticle Corona upon Contact with Lung Surfactant Reveals Differences in Protein, but Not Lipid Composition

TLDR

Pulmonary surfactant, rich in phospholipids and surfactant proteins, forms the first line of host defense in the deep lung and is expected to generate a nanoparticle corona distinct from that formed in plasma. The study aims to characterize nanoparticle corona formation using native porcine surfactant as a model. The authors incubated PEG-, PLGA-, and lipid‑coated nanoparticles with porcine surfactant and applied label‑free shotgun proteomics and LC–MS lipidomics to quantify the adsorbed biomolecules. The coronas of PEG-, PLGA-, and lipid‑coated nanoparticles all share a conserved lipid profile, but differ markedly in protein composition, with up to 417 proteins identified and a predominance of lipid‑ and surface‑binding proteins such as SP‑A, SP‑D, and DMBT1, indicating that selective protein adsorption drives the similar lipid pattern and providing a unique quantitative dataset distinct from plasma coronas.

Abstract

Pulmonary surfactant (PS) constitutes the first line of host defense in the deep lung. Because of its high content of phospholipids and surfactant specific proteins, the interaction of inhaled nanoparticles (NPs) with the pulmonary surfactant layer is likely to form a corona that is different to the one formed in plasma. Here we present a detailed lipidomic and proteomic analysis of NP corona formation using native porcine surfactant as a model. We analyzed the adsorbed biomolecules in the corona of three NP with different surface properties (PEG-, PLGA-, and Lipid-NP) after incubation with native porcine surfactant. Using label-free shotgun analysis for protein and LC–MS for lipid analysis, we quantitatively determined the corona composition. Our results show a conserved lipid composition in the coronas of all investigated NPs regardless of their surface properties, with only hydrophilic PEG-NPs adsorbing fewer lipids in total. In contrast, the analyzed NP displayed a marked difference in the protein corona, consisting of up to 417 different proteins. Among the proteins showing significant differences between the NP coronas, there was a striking prevalence of molecules with a notoriously high lipid and surface binding, such as, e.g., SP-A, SP-D, DMBT1. Our data indicate that the selective adsorption of proteins mediates the relatively similar lipid pattern in the coronas of different NPs. On the basis of our lipidomic and proteomic analysis, we provide a detailed set of quantitative data on the composition of the surfactant corona formed upon NP inhalation, which is unique and markedly different to the plasma corona.