title: Molecular recognition in poly(epsilon-caprolactone)-based thermoplastic elastomers.
abstract: The molecular recognition properties of the hydrogen bonding segments in biodegradable thermoplastic elastomers were explored, aiming at the further functionalization of these potentially interesting biomaterials. A poly(epsilon-caprolactone)-based poly(urea) 2 was synthesized and characterized in terms of mechanical properties, processibility and histocompatibility. Comparison of the data with those obtained from the structurally related poly(urethane urea) 1 revealed that the difference in hard segment structure does not significantly affect the potency for application as a biomaterial. Nevertheless, the small differences in hard block composition had a strong effect on the molecular recognition properties of the hydrogen bonding segments. High selectivity was found for poly(urea) 2 in which bisureidobutylene-functionalized azobenzene dye 3 was selectively incorporated while bisureidopentylene-functionalized azobenzene dye 4 was completely released. In contrast, the incorporation of both dyes in poly(urethane urea) 1 led in both cases to their gradual release in time. Thermal analysis of the polymers in combination with variable temperature infrared experiments indicated that the hard blocks in 1 showed a sharp melting point, whereas those in 2 showed a very broad melting trajectory. This suggests a more precise organization of the hydrogen bonding segments in the hard blocks of poly(urea) 2 compared to poly(urethane urea) 1 and explains the results from the molecular recognition experiments. Preliminary results revealed that a bisureidobutylene-functionalized GRGDS peptide showed more supramolecular interaction with the PCL-based poly(urea), containing the bisureidobutylene recognition unit, as compared to HMW PCL, lacking this recognition unit.
authors.affiliation: Laboratory of Macromolecular and Organic Chemistry, Eindhoven University of Technology, P.O. Box 513, NL-5600 MB Eindhoven, The Netherlands.
authors.forename: Eva
authors.initials: E
authors.lastname: Wisse
authors.forename: A J H
authors.initials: AJ
authors.lastname: Spiering
authors.forename: Ellen N M
authors.initials: EN
authors.lastname: van Leeuwen
authors.forename: Raymond A E
authors.initials: RA
authors.lastname: Renken
authors.forename: Patricia Y W
authors.initials: PY
authors.lastname: Dankers
authors.forename: Linda A
authors.initials: LA
authors.lastname: Brouwer
authors.forename: Marja J A
authors.initials: MJ
authors.lastname: van Luyn
authors.forename: Martin C
authors.initials: MC
authors.lastname: Harmsen
authors.forename: Nico A J M
authors.initials: NA
authors.lastname: Sommerdijk
authors.forename: E W
authors.initials: EW
authors.lastname: Meijer
mesh_terms: D016475:3T3 Cells; D000818:Animals; D001672:Biocompatible Materials; D002152:Calorimetry, Differential Scanning; D002455:Cell Division; D020724:Elastomers / Q000138:chemical synthesis / Q000737:chemistry*; D051379:Mice; D018625:Microscopy, Atomic Force; D008958:Models, Molecular; D008968:Molecular Conformation; D011091:Polyesters / Q000138:chemical synthesis / Q000737:chemistry*; D013499:Surface Properties; D013816:Thermodynamics
chemical_list: D001672:Biocompatible Materials; D020724:Elastomers; D011091:Polyesters; C016240:polycaprolactone