title: A Route to Aliphatic Poly(ester)s with Thiol Pendant Groups: From Monomer Design to Editable Porous Scaffolds.
abstract: Biodegradable aliphatic polyesters such as poly(lactide) and poly(ε-caprolactone), largely used in tissue engineering applications, lack suitable functional groups and biological cues to enable interactions with cells. Because of the ubiquity of thiol groups in the biological environment and the pliability of thiol chemistry, we aimed to design and synthesize poly(ester) chains bearing pendant thiol-protected groups. To achieve this, 3-methyl-6-(tritylthiomethyl)-1,4-dioxane-2,5-dione, a lactide-type monomer possessing a pendant thiol-protected group, was synthesized. This molecule, when used as a monomer in controlled ring-opening polymerization in combination with lactide and ε-caprolactone, appeared to be a convenient "building block" for the preparation of functionalized aliphatic copolyesters, which were easily modified further. A polymeric sample bearing pyridyl disulfide groups, able to bind a cysteine-containing peptide, was efficiently obtained from a two-step modification reaction. Porous scaffolds were then prepared by blending this latter copolymer sample with poly(L-lactide-co-ε-caprolactone) followed by salt leaching. A further disulfide exchange reaction performed in aqueous medium formed porous scaffolds with covalently linked arginine-glycine-aspartic acid sequences. The scaffolds were characterized by thermal and mechanical tests, and scanning electron microscopy surface images revealed a highly porous morphology. Moreover, a cytotoxicity test indicated good cell viability.
authors.affiliation: Department of Fibre and Polymer Technology, KTH Royal Institute of Technology , 114 28 Stockholm, Sweden.|Department of Chemistry and Biology "A. Zambelli", University of Salerno , via Giovanni Paolo II 132, 84084 Fisciano, Salerno, Italy.
authors.forename: Tiziana
authors.initials: T
authors.lastname: Fuoco
authors.affiliation: Department of Fibre and Polymer Technology, KTH Royal Institute of Technology , 114 28 Stockholm, Sweden.
authors.forename: Anna
authors.initials: A
authors.lastname: Finne-Wistrand
authors.affiliation: Department of Fibre and Polymer Technology, KTH Royal Institute of Technology , 114 28 Stockholm, Sweden.|Department of Science and Technology, University of Sannio , via dei Mulini 59/A, 82100 Benevento, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Pappalardo
mesh_terms: D001672:Biocompatible Materials / Q000138:chemical synthesis* / Q000737:chemistry*; D002208:Caproates / Q000737:chemistry; D004146:Dioxanes / Q000138:chemical synthesis / Q000737:chemistry*; D016503:Drug Delivery Systems; D007783:Lactones / Q000138:chemical synthesis / Q000737:chemistry*; D011091:Polyesters / Q000737:chemistry; D011108:Polymers; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds
chemical_list: D001672:Biocompatible Materials; D002208:Caproates; D004146:Dioxanes; D007783:Lactones; D011091:Polyesters; D011108:Polymers; C016240:polycaprolactone; C033616:poly(lactide); C121056:caprolactone