Functionalization of graphene oxide generates a unique interface for selective serum protein interactions

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Immunology

Background:

• Nanomaterial use in biomedicine raises concerns about potential toxicity, allergy, and inflammation.
• Graphene oxide (GO) can adsorb serum proteins and activate the complement system, leading to inflammatory responses.

Purpose of the Study:

• To investigate the serum behaviors of graphene oxide (GO) and the impact of surface modification, specifically PEGylation.
• To evaluate the potential of PEGylated GO (nGO-PEG) in modulating immune responses induced by nanomaterials.

Main Methods:

• Incubation of unfunctionalized GO and PEGylated nGO-PEG with human sera.
• Analysis of protein adsorption and complement C3 cleavage using mass spectrometry and Western blot.
• Proof-of-concept experiment demonstrating nGO-PEG's ability to mitigate C3a/C3a(des-Arg) levels.

Main Results:

• Unfunctionalized GO strongly adsorbed proteins and induced complement C3 cleavage, generating inflammatory anaphylatoxin C3a/C3a(des-Arg).
• PEGylated nGO-PEG showed reduced protein binding and complement C3 activation.
• nGO-PEG exhibited selective binding to immune-related proteins, including C3a/C3a(des-Arg), and decreased its levels in sera.
• nGO-PEG demonstrated potential in eliminating C3a/C3a(des-Arg) induced by other nanomaterials.

Conclusions:

• Surface modification, particularly PEGylation, is crucial for regulating the nanobiointerface and mitigating adverse biological effects of nanomaterials.
• PEGylated GO presents a novel strategy for modulating nanomaterial-induced immune responses.
• Understanding nanobio interactions is key to developing safer nanomaterials for biomedical applications.