title: Reducing protein adsorption with polymer-grafted hyaluronic acid coatings.
abstract: We report a thermoresponsive chemical modification strategy of hyaluronic acid (HA) for coating onto a broad range of biomaterials without relying on chemical functionalization of the surface. Poly(di(ethylene glycol) methyl ether methacrylate) (PMEO2MA), a polymer with a lower critical solution temperature of 26 °C in water, was grafted onto HA to allow facile formation of biopolymer coatings. While the mechanism for film formation appears to involve a complex combination of homogeneous nucleation followed by heterogeneous film growth, we demonstrate that it resulted in hydrophilic coatings that significantly reduce protein adsorption despite the high fraction of hydrophobic (PMEO2MA). Structural characterization was performed using atomic force microscopy (AFM), which showed the formation of a dense, continuous coating based on 200 nm domains that were stable in protein solutions for at least 15 days. The coatings had a water contact angle of 16°, suggesting the formation of hydrophilic but not fully wetting films. Quartz crystal microbalance with dissipation monitoring (QCM-D) as well as biolayer interferometry (BLI) techniques were used to measure adsorption of bovine serum albumin (BSA), fibrinogen (Fbg), and human immunoglobulin (IgG), with results indicating that HA-PMEO2MA-coated surfaces effectively inhibited adsorption of all three serum proteins. These results are consistent with previous studies demonstrating that this degree of hydrophilicity is sufficient to generate an effectively nonfouling surface and suggest that segregation during the solubility transition resulted in a surface that presented the hydrophilic HA component of the hybrid biopolymer. We conclude that PMEO2MA-grafted HA is a versatile platform for the passivation of hydrophobic biomaterial surfaces without need for substrate functionalization.
authors.affiliation: Department of Chemistry, ‡Department of Chemical Engineering, and §Department of Biomedical Engineering, Carnegie Mellon University , Pittsburgh, Pennsylvania 15213, United States.
authors.forename: Mohamed H
authors.initials: MH
authors.lastname: Ramadan
authors.forename: Joseph E
authors.initials: JE
authors.lastname: Prata
authors.forename: Orsolya
authors.initials: O
authors.lastname: Karácsony
authors.forename: Gunnar
authors.initials: G
authors.lastname: Dunér
authors.forename: Newell R
authors.initials: NR
authors.lastname: Washburn
mesh_terms: D000327:Adsorption; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry; D002417:Cattle; D005340:Fibrinogen / Q000737:chemistry; D006801:Humans; D006820:Hyaluronic Acid / Q000097:blood*; D057927:Hydrophobic and Hydrophilic Interactions; D007074:Immunoglobulin G / Q000737:chemistry; D018625:Microscopy, Atomic Force; D011092:Polyethylene Glycols / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D011506:Proteins / Q000737:chemistry*; D012710:Serum Albumin, Bovine / Q000737:chemistry; D013499:Surface Properties
chemical_list: D001672:Biocompatible Materials; D007074:Immunoglobulin G; D011108:Polymers; D011506:Proteins; D012710:Serum Albumin, Bovine; D011092:Polyethylene Glycols; D005340:Fibrinogen; D006820:Hyaluronic Acid