title: Stealth Immune Properties of Graphene Oxide Enabled by Surface-Bound Complement Factor H.
abstract: With mounting evidence that nanomaterials can trigger adverse innate immune responses such as complement activation, there is increasing attention to the development of strategies that mask the complement-activating properties of nanomaterials. The current gold standard to reduce complement activation of nanomaterials is the covalent attachment of polymer coatings on nanomaterial surfaces, even though this strategy provides only moderate protection against complement activation. Akin to protein coronas that form on nanomaterial surfaces in physiological fluids, noncovalent strategies based on protein adsorption would offer a simplified, biomimetic approach to mitigate complement activation. Herein, we demonstrate that precoating graphene-based nanomaterials with purified, natural proteins enables regulatory control of nanomaterial-triggered complement activation. When the graphene-based nanomaterials were coated with complement factor H, nearly complete protection (>90% reduction) against complement activation (a "stealth effect") was achieved. By contrast, coating the nanomaterials with a passivating layer of bovine or human serum albumins achieved moderate protection (∼40% reduction), whereas immunoglobulin G amplified complement activation by several-fold. Taken together, our results demonstrate that surface-bound factor H, as well as serum albumins, can prevent graphene oxide-triggered complement activation, thereby offering a facile approach to inhibit complement activation completely down to naturally occurring levels.
authors: School of Materials Science and Engineering, Nanyang Technological University , 50 Nanyang Avenue 639798, Singapore.
authors: Jason N
authors: JN
authors: Belling
authors: School of Materials Science and Engineering, Nanyang Technological University , 50 Nanyang Avenue 639798, Singapore.
authors: Joshua A
authors: JA
authors: Jackman
authors: School of Materials Science and Engineering, Nanyang Technological University , 50 Nanyang Avenue 639798, Singapore.
authors: Saziye
authors: S
authors: Yorulmaz Avsar
authors: School of Materials Science and Engineering, Nanyang Technological University , 50 Nanyang Avenue 639798, Singapore.
authors: Jae Hyeon
authors: JH
authors: Park
authors: School of Materials Science and Engineering, Nanyang Technological University , 50 Nanyang Avenue 639798, Singapore.
authors: Yan
authors: Y
authors: Wang
authors: School of Materials Science and Engineering, Nanyang Technological University , 50 Nanyang Avenue 639798, Singapore.
authors: Michael G
authors: MG
authors: Potroz
authors: School of Materials Science and Engineering, Nanyang Technological University , 50 Nanyang Avenue 639798, Singapore.
authors: Abdul Rahim
authors: AR
authors: Ferhan
authors: Paul S
authors: PS
authors: Weiss
authors: School of Materials Science and Engineering, Nanyang Technological University , 50 Nanyang Avenue 639798, Singapore.|School of Chemical and Biomedical Engineering, Nanyang Technological University , 62 Nanyang Drive 637459, Singapore.
authors: Nam-Joon
authors: NJ
authors: Cho
keywords: complement activation; factor H; graphene oxide; immunomodulation; protein coating; protein corona; serum albumin