Sequential nucleophilic substitutions permit orthogonal click functionalization of multicomponent PEG brushes.
Multicomponent poly(ethylene glycol) (PEG) brushes (i.e., ≥ 2 adjacent PEG brushes) can be used to engineer culture substrates with microscale, nonfouling regions decorated with covalently immobilized ligands that mediate biospecific interactions. However, synthesizing such brushes with orthogonal immobilization chemistries to permit differential biofunctionalization is nontrivial and often requires synthesis of PEG-co-polymers. To simplify synthesis and enhance the versatility of such substrates, we developed a protocol for generating orthogonal click-functionalized multicomponent PEG brushes using sequential nucleophilic substitutions by sodium azide, ethanolamine, and propargylamine. The novel application of propargylamine-mediated substitution functionalizes PEG brushes with acetylene groups, and for the first time, ethanolamine-mediated substitution is shown to be sufficient for passivating the "living" polymer chain ends between brush synthesis steps. Thus, our multicomponent PEG brushes present dual orthogonal chemistries (i.e., azido and acetylene groups) for ligand immobilization via versatile copper-free click reactions, which are useful for in situ surface modifications during cell culture.
Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, Wisconsin, United States.
Jin
J
Sha
Ethan S
ES
Lippmann
Jason
J
McNulty
Yulu
Y
Ma
Randolph S
RS
Ashton
D002448:Cell Adhesion; D018929:Cell Culture Techniques; D002478:Cells, Cultured; D057930:Click Chemistry; D053595:Embryonic Stem Cells / Q000502:physiology; D061307:Human Umbilical Vein Endothelial Cells / Q000502:physiology; D006801:Humans; D007700:Kinetics; D011092:Polyethylene Glycols / Q000138:chemical synthesis* / Q000737:chemistry; D011109:Polymethacrylic Acids / Q000138:chemical synthesis* / Q000737:chemistry; D013499:Surface Properties
D011109:Polymethacrylic Acids; D011092:Polyethylene Glycols