Mussel Adhesive Protein Mimetic Polymers for the Preparation of Nonfouling Surfaces

Abstract

A new biomimetic strategy for modification of biomaterial surfaces with poly(ethylene glycol) (PEG) was developed. The strategy exploits the adhesive characteristics of 3,4-dihydroxyphenylalanine (DOPA), an important component of mussel adhesive proteins, to anchor PEG onto surfaces, rendering the surfaces resistant to cell attachment. Linear monomethoxy-terminated PEGs were conjugated either to a single DOPA residue (mPEG-DOPA) or to the N-terminus of Ala-Lys-Pro-Ser-Tyr-Hyp-Hyp-Thr-DOPA-Lys (mPEG-MAPD), a decapeptide analogue of a protein found in Mytilus edulis adhesive plaques. Gold and titanium surfaces were modified by adsorption of mPEG-DOPA and mPEG-MAPD from solution, after which surface analysis by X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectroscopy confirmed the presence of immobilized PEG on the surface. The ability of modified surfaces to resist cell attachment was examined by culturing 3T3 fibroblasts on the surfaces for up to 14 days. Quantitative image analysis revealed that cell adhesion to mPEG-DOPA and mPEG-MAPD modified surfaces decreased by as much as 98% compared to control surfaces. Modified Ti surfaces exhibited low cell adhesion for up to 2 weeks in culture, indicating that the nonfouling properties of mPEG-DOPA and mPEG-MAPD treated surfaces persist for extended periods of time. This strategy paradoxically exploits the strong fouling characteristics of MAP analogues for antifouling purposes and may be broadly applied to medical implants and diagnostics, as well as numerous nonmedical applications in which the minimization of surface fouling is desired.

Surface Presentation of Bioactive Ligands in a Nonadhesive Background Using DOPA-Tethered Biotinylated Poly(ethylene glycol)

“…A. Woodlam, Inc.). The reported thickness, before and after the adsorption of streptavidin and biotinylated IgG 1 (5-8 biotin molecules per IgG 1 ; biotin (5)(6)(7)(8) -IgG 1 ; BD Biosciences, San Jose, CA), was the average from 3 surfaces with 3 different spots measured on each surface. XPS spectra were collected on an Omicron ESCALAB (Omicron, Taunusstein, Germany) with a monochromatic Al Kα (1486.6 eV) 300-W X-ray source.…”

“…We examined sequential adsorption of streptavidin and biotin (5)(6)(7)(8) -IgG 1 to characterize the binding activity of DPB/DP surfaces. Nonspecific adsorption of streptavidin and biotin (5)(6)(7)(8) IgG 1 was very low for surfaces coated with 100% DP (DPB0) (Fig.…”

“…We have previously shown that DOPA-PEG5000 surfaces greatly reduce the nonspecific adhesion of proteins and cells 8,20 . The non-fouling properties of PEG5000 improved with increasing DOPA content, due to the corresponding increase in the PEG5000 surface density.…”

Multifunctional biomaterial coatings: synthetic challenges and biological activity

“…Other investigations demonstrated a half-life of 14 days on titanium in buffer and at room temperature (Tang et al, 2014). Furthermore, cell-repellent properties of DOPA-modified PEG-coatings were stable over 14 days, highlighting the strong anchorage under cell culture conditions (Dalsin et al, 2003). Two different approaches are mainly used to apply mussel adhesive properties in the field of biomaterials.…”

“…On the other hand, DOPA is incorporated into polymers or recombinantly expressed proteins (mussel foot proteins from the blue mussel (Mytilus edulis) by enzymatic hydroxylation of tyrosine residues (Hwang et al, 2007). Whereas in small artificial peptides DOPA is primarily responsible for adhesion to the surface, it is also relevant in proteins and polymers for crosslinking with itself or with amino groups to obtain a three-dimensional network (Yu et al, 1999;Burzio and Waite, 2000;Dalsin et al, 2003;Byun et al, 2014). Beyond that, different strategies to introduce functional moieties in DOPA-containing molecules are applied.…”