title: Influence of Block Copolymerization on the Antifreeze Protein Mimetic Ice Recrystallization Inhibition Activity of Poly(vinyl alcohol).
abstract: Antifreeze (glyco) proteins are produced by many cold-acclimatized species to enable them to survive subzero temperatures. These proteins have multiple macroscopic effects on ice crystal growth which makes them appealing for low-temperature applications-from cellular cryopreservation to food storage. Poly(vinyl alcohol) has remarkable ice recrystallization inhibition activity, but its mode of action is uncertain as is the extent at which it can be incorporated into other high-order structures. Here the synthesis and characterization of well-defined block copolymers containing poly(vinyl alcohol) and poly(vinylpyrrolidone) by RAFT/MADIX polymerization is reported, as new antifreeze protein mimetics. The effect of adding a large second hydrophilic block is studied across a range of compositions, and it is found to be a passive component in ice recrystallization inhibition assays, enabling retention of all activity. In the extreme case, a block copolymer with only 10% poly(vinyl alcohol) was found to retain all activity, where statistical copolymers of PVA lose all activity with very minor changes to composition. These findings present a new method to increase the complexity of antifreeze protein mimetic materials, while retaining activity, and also to help understand the underlying mechanisms of action.
authors.affiliation: Department of Chemistry, University of Warwick , Coventry, CV4 7AL, U.K.
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Congdon
authors.affiliation: Department of Chemistry, University of Warwick , Coventry, CV4 7AL, U.K.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Notman
authors.affiliation: Department of Chemistry, University of Warwick , Coventry, CV4 7AL, U.K.|Warwick Medical School, University of Warwick , Coventry, CV4 7AL, U.K.
authors.forename: Matthew I
authors.initials: MI
authors.lastname: Gibson
mesh_terms: D021301:Antifreeze Proteins / Q000737:chemistry*; D040761:Biomimetic Materials / Q000737:chemistry*; D003451:Cryoprotective Agents / Q000737:chemistry*; D003460:Crystallization; D057927:Hydrophobic and Hydrophilic Interactions; D007053:Ice; D058105:Polymerization; D011142:Polyvinyl Alcohol / Q000737:chemistry*
chemical_list: D021301:Antifreeze Proteins; D003451:Cryoprotective Agents; D007053:Ice; D011142:Polyvinyl Alcohol