title: Polythiolactone-based redox-responsive layers for the reversible release of functional molecules.
abstract: The development of thin macromolecular layers with incorporated disulfide bonds that can be disrupted and formed again under redox stimulation is of general interest for drug release applications, because such layers can provide rapid and reversible responses to specific biological systems and signals. However, the preparation of such layers from polythiols remains difficult, because of the fast oxidation of thiol groups in ambient conditions. Here we propose water-soluble thiolactone-containing copolymers as stable precursors containing protected thiol groups, allowing us to produce on demand polythiol layers on gold substrates in the presence of amine derivatives. Electrochemical, water contact angle, X-ray photoelectron spectroscopy, and X-ray reflectometry measurements evidence the formation of uniform copolymer layers containing both anchored and free thiol groups. The number of free thiols increases with the content of thiolactone units in the copolymers. In a second step, a thiolated dye, used as a model drug, was successfully grafted on the free thiol groups through disulfide bonds using mild oxidizing conditions, as proved by fluorescence and quartz crystal microbalance measurements. Finally, the reversible release/regrafting of the dye under redox stimulation is demonstrated.
authors.affiliation: Institute of Condensed Matter & Nanosciences (Bio & Soft Matter), Université catholique de Louvain , Croix du Sud 1, box L7.04.01, B-1348 Louvain-La-Neuve, Belgium.
authors.forename: Sabrina
authors.initials: S
authors.lastname: Belbekhouche
authors.forename: Stefan
authors.initials: S
authors.lastname: Reinicke
authors.forename: Pieter
authors.initials: P
authors.lastname: Espeel
authors.forename: Filip E
authors.initials: FE
authors.lastname: Du Prez
authors.forename: Pierre
authors.initials: P
authors.lastname: Eloy
authors.forename: Christine
authors.initials: C
authors.lastname: Dupont-Gillain
authors.forename: Alain M
authors.initials: AM
authors.lastname: Jonas
authors.forename: Sophie
authors.initials: S
authors.lastname: Demoustier-Champagne
authors.forename: Karine
authors.initials: K
authors.lastname: Glinel
mesh_terms: D000327:Adsorption; D003692:Delayed-Action Preparations / Q000737:chemistry*; D004220:Disulfides / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D007783:Lactones / Q000737:chemistry*; D008422:Materials Testing; D010084:Oxidation-Reduction; D011108:Polymers / Q000737:chemistry*; D013438:Sulfhydryl Compounds / Q000737:chemistry*
chemical_list: D003692:Delayed-Action Preparations; D004220:Disulfides; D007783:Lactones; D011108:Polymers; D013438:Sulfhydryl Compounds; D006046:Gold
keywords: disulfide link; drug release; gold surface modification; polythiol; responsive surface; stimuli-responsive polymer; thiolactone aminolysis