title: Thiol click modification of cyclic disulfide containing biodegradable polyurethane urea elastomers.
abstract: Although the thiol click reaction is an attractive tool for postpolymerization modification of thiolmers, thiol groups are easily oxidized, limiting the potential for covalent immobilization of bioactive molecules. In this study, a series of biodegradable polyurethane elastomers incorporating stable cyclic disulfide groups was developed and characterized. These poly(ester urethane)urea (PEUU-SS) polymers were based on polycaprolactone diol (PCL), oxidized dl-dithiothreitol (O-DTT), lysine diisocyanate (LDI), or butyl diisocyanate (BDI), with chain extension by putrescine. The ratio of O-DTT:PCL was altered to investigate different levels of potential functionalization. PEG acrylate was employed to study the mechanism and availability of both bulk and surface click modification of PEUU-SS polymers. All synthesized PEUU-SS polymers were elastic with breaking strengths of 38-45 MPa, while the PEUU-SS(LDI) polymers were more amorphous, possessing lower moduli and relatively small permanent deformations versus PEUU-SS(BDI) polymers. Variable bulk click modification of PEUU-SS(LDI) polymers was achieved by controlling the amount of reduction reagent, and rapid reaction rates occurred using a one-pot, two-step process. Likewise, surface click reaction could be carried out quickly under mild, aqueous conditions. Furthermore, a maleimide-modified affinity peptide (TPS) was successfully clicked on the surface of an electrospun PEUU-SS(BDI) fibrous sheet, which improved endothelial progenitor cell adhesion versus corresponding unmodified films. The cyclic disulfide containing biodegradable polyurethanes described provide an option for cardiovascular and other soft tissue regenerative medicine applications where a temporary, elastic scaffold with designed biofunctionality from a relatively simple click chemistry approach is desired.
authors.affiliation: †State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, 2999 North Renmin Road, Shanghai 201620, China.|‡McGowan Institute for Regenerative Medicine, University of Pittsburgh, 450 Technology Drive, Suite 300, Pittsburgh, Pennsylvania 15219, United States.|§Department of Surgery, University of Pittsburgh, 200 Lothrop Street F600, Pittsburgh, Pennsylvania 15219, United States.|∥College of Chemistry and Chemical Engineering and Biological Engineering, Donghua University, 2999 North Renmin Road, Shanghai 201620, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Fang
authors.affiliation: ‡McGowan Institute for Regenerative Medicine, University of Pittsburgh, 450 Technology Drive, Suite 300, Pittsburgh, Pennsylvania 15219, United States.|§Department of Surgery, University of Pittsburgh, 200 Lothrop Street F600, Pittsburgh, Pennsylvania 15219, United States.
authors.forename: Sang-Ho
authors.initials: SH
authors.lastname: Ye
authors.affiliation: †State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, 2999 North Renmin Road, Shanghai 201620, China.|∥College of Chemistry and Chemical Engineering and Biological Engineering, Donghua University, 2999 North Renmin Road, Shanghai 201620, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.affiliation: ⊥Department of Pharmacology, School of Pharmacy, Second Military Medical University, 325 Guo He Road, Shanghai 200433, China.
authors.forename: Ting
authors.initials: T
authors.lastname: Zhao
authors.affiliation: †State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, 2999 North Renmin Road, Shanghai 201620, China.|∥College of Chemistry and Chemical Engineering and Biological Engineering, Donghua University, 2999 North Renmin Road, Shanghai 201620, China.
authors.forename: Xiumei
authors.initials: X
authors.lastname: Mo
authors.affiliation: ‡McGowan Institute for Regenerative Medicine, University of Pittsburgh, 450 Technology Drive, Suite 300, Pittsburgh, Pennsylvania 15219, United States.|§Department of Surgery, University of Pittsburgh, 200 Lothrop Street F600, Pittsburgh, Pennsylvania 15219, United States.|#Department of Chemical Engineering, University of Pittsburgh, 1249 Benedum Hall, Pittsburgh, Pennsylvania 15261, United States.|▽Department of Bioengineering, University of Pittsburgh, 3700 O'Hara Street, Pittsburgh, Pennsylvania 15261, United States.
authors.forename: William R
authors.initials: WR
authors.lastname: Wagner
mesh_terms: D063566:Biodegradable Plastics / Q000737:chemistry*; D004220:Disulfides / Q000737:chemistry; D020724:Elastomers / Q000737:chemistry; D011140:Polyurethanes / Q000737:chemistry*; D013438:Sulfhydryl Compounds / Q000737:chemistry*; D014508:Urea / Q000737:chemistry
chemical_list: D063566:Biodegradable Plastics; D004220:Disulfides; D020724:Elastomers; D011140:Polyurethanes; D013438:Sulfhydryl Compounds; D014508:Urea