Paper Title
Nano-Coating Of Living Cells By Surface-Initiated Radical Polymerization From The Cell Surface

Abstract
Simple but highly versatile in the formation of polymerbrushes on solid substrates is surface-initiated, atom-transferradical polymerization (SI-ATRP), where polymers aregrown, by controlled radical reactions, from the ATRPinitiators that are introduced onto a substrate.1Although hybrid structures of living cells and syntheticpolymers have a great deal of potential in cell-based applications,such as cell-based sensors, biomotors, biocatalysis,theranostics, cell therapy, and cells-on-a-chip, it is extremelychallenging to perform SI-ATRP (and of course otherpolymerization protocols) on the surfaces of individual livingcells, because the reaction conditions are lethal to chemicallylabile cells.2 In this work, a cytocompatible method of surface-initiated, activator regenerated by electron transfer, atom transfer radical polymerization (SI-ARGETATRP) is developed for engineering cell surfaces with synthetic polymers.3 Dopamine-based ATRP initiators are used for both introducing the ATRP initiator onto chemically complex cell surfaces uniformly (by the material-independent coating property of polydopamine)and protecting the cells from radical attack during polymerization (by the radical-scavenging property of polydopamine).Synthetic polymers are grafted onto the surface of individual yeast cells without significant loss of cell viability, and theuniform and dense grafting is confirmed by various characterization methods including agglutination assay and cell-division studies. This work will provide a strategic approach to the generation of living cell–polymer hybrid structures and open the door to their application in multitude of areas, such as sensor technology, catalysis, theranostics, and cell therapy. Keywords: ATRP, Cell encapsulation, Nano-coating, cell surface modification, surface-initiated, polydopamine