title: Tuning the properties and functions of 17β-estradiol-polysaccharide conjugates in thin films: impact of sample history.
abstract: In addition to its role in the regulation of sex-related processes, 17β-estradiol (E2) participates in the prevention and treatment of cardiovascular diseases via nongenomic pathways mediated by estrogen receptors (ER-α) located in the cell membrane. To achieve specific nongenomic activity of E2, we linked E2 (4.4 mol %) to chitosan-phosphorylcholine (CH-PC) (20 mol % PC). Injections of ER-α solutions (5 to 100 nmol L(-1)) over rehydrated CH-PC-E2 thin films led to permanent adsorption of ER-α to the film surface, as detected by quartz crystal microbalance with dissipation (QCM-D). However, ER-α did not bind onto CH-PC-E2 films formed in situ and never dried. X-ray photoelectron spectroscopy (XPS) analysis of spin-cast CH-PC-E2 films revealed significant E2 enrichment of the topmost section of the film, attributed to the preferential migration of E2 toward the film/air interface upon drying. Mechanical analysis of CH-PC-E2 films in the frequency domain probed by QCM-D indicated that rehydrated films behave as an entangled network with junction points formed by self-assembly of hydrophobic E2 moieties and by ion pairing among PC groups, whereas films formed in situ are entangled polymer solutions with temporary junctions. The structural analysis presented offers useful guidelines for the study of amphiphilic biomacromolecules designed for therapeutic use as thin films.
authors.affiliation: Faculté de Pharmacie and Département de Chimie, Université de Montréal, CP 6128 Succursale Centre Ville, Montréal, QC, H3C 3J7, Canada.
authors.forename: Zhimei
authors.initials: Z
authors.lastname: Miao
authors.forename: Piotr
authors.initials: P
authors.lastname: Kujawa
authors.forename: Yiu-Ting Richard
authors.initials: YT
authors.lastname: Lau
authors.forename: Sayaka
authors.initials: S
authors.lastname: Toita
authors.forename: Baowen
authors.initials: B
authors.lastname: Qi
authors.forename: Jun
authors.initials: J
authors.lastname: Nakanishi
authors.forename: Isabelle
authors.initials: I
authors.lastname: Cloutier
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Tanguay
authors.forename: Françoise M
authors.initials: FM
authors.lastname: Winnik
mesh_terms: D001672:Biocompatible Materials / Q000138:chemical synthesis*; D048271:Chitosan / Q000737:chemistry; D004958:Estradiol / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D018625:Microscopy, Atomic Force; D010767:Phosphorylcholine / Q000737:chemistry; D056951:Photoelectron Spectroscopy / Q000379:methods; D011108:Polymers / Q000138:chemical synthesis; D011134:Polysaccharides / Q000737:chemistry*; D058525:Quartz Crystal Microbalance Techniques / Q000379:methods; D013499:Surface Properties
chemical_list: D001672:Biocompatible Materials; D011108:Polymers; D011134:Polysaccharides; D010767:Phosphorylcholine; D004958:Estradiol; D048271:Chitosan