title: Elastic poly(ε-caprolactone)-polydimethylsiloxane copolymer fibers with shape memory effect for bone tissue engineering.
abstract: A porous shape memory scaffold with biomimetic architecture is highly promising for bone tissue engineering applications. In this study, a series of new shape memory polyurethanes consisting of organic poly(ε-caprolactone) (PCL) segments and inorganic polydimethylsiloxane (PDMS) segments in different ratios (9 : 1, 8 : 2 and 7 : 3) was synthesised. These PCL-PDMS copolymers were further engineered into porous fibrous scaffolds by electrospinning. With different ratios of PCL: PDMS, the fibers showed various fiber diameters, thermal behaviour and mechanical properties. Even after being processed into fibrous structures, these PCL-PDMS copolymers maintained their shape memory properties, and all the fibers exhibited excellent shape recovery ratios of  >90% and shape fixity ratios of  >92% after 7 thermo-mechanical cycles. Biological assay results corroborated that the fibrous PCL-PDMS scaffolds were biocompatible by promoting osteoblast proliferation, functionally enhanced biomineralization-relevant alkaline phosphatase expression and mineral deposition. Our study demonstrated that the PCL-PDMS fibers with excellent shape memory properties are promising substrates as bioengineered grafts for bone regeneration.
authors.affiliation: Institute of Materials Research and Engineering (IMRE), A*STAR, 2 Fusionopolis Way. Innovis, #08-03, 138634, Singapore.
authors.forename: Dan
authors.initials: D
authors.lastname: Kai
authors.forename: Molamma P
authors.initials: MP
authors.lastname: Prabhakaran
authors.forename: Benjamin Qi Yu
authors.initials: BQ
authors.lastname: Chan
authors.forename: Sing Shy
authors.initials: SS
authors.lastname: Liow
authors.forename: Seeram
authors.initials: S
authors.lastname: Ramakrishna
authors.forename: Fujian
authors.initials: F
authors.lastname: Xu
authors.forename: Xian Jun
authors.initials: XJ
authors.lastname: Loh
mesh_terms: D018786:Bone Substitutes / Q000138:chemical synthesis*; D049109:Cell Proliferation / Q000502:physiology; D002470:Cell Survival / Q000502:physiology; D002478:Cells, Cultured; D004129:Dimethylpolysiloxanes / Q000737:chemistry*; D055119:Elastic Modulus; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006358:Hot Temperature; D006801:Humans; D057139:Nanofibers / Q000737:chemistry* / Q000648:ultrastructure; D010006:Osteoblasts / Q000166:cytology / Q000502:physiology*; D011091:Polyesters / Q000138:chemical synthesis*; D013314:Stress, Mechanical; D013718:Tensile Strength; D023822:Tissue Engineering / Q000295:instrumentation / Q000379:methods; D054457:Tissue Scaffolds
chemical_list: D018786:Bone Substitutes; D004129:Dimethylpolysiloxanes; D011091:Polyesters; C016240:polycaprolactone; C013830:baysilon