title: Synthesis of Thermoresponsive Amphiphilic Polyurethane Gel as a New Cell Printing Material near Body Temperature.
abstract: Waterborne polyurethane (PU) based on poly(ε-caprolactone) (PCL) diol and a second oligodiol containing amphiphilic blocks was synthesized in this study. The microstructure was characterized by dynamic light scattering (DLS), small-angle X-ray scattering (SAXS), and rheological measurement of the PU dispersion. The surface hydrophilicity measurement, infrared spectroscopy, wide-angle X-ray diffraction, mechanical and thermal analyses were conducted in solid state. It was observed that the presence of a small amount of amphiphilic blocks in the soft segment resulted in significant changes in microstructure. When 90 mol % PCL diol and 10 mol % amphiphilic blocks of poly(l-lactide)-poly(ethylene oxide) (PLLA-PEO) diol were used as the soft segment, the synthesized PU had a water contact angle of ∼24° and degree of crystallinity of ∼14%. The dispersion had a low viscosity below room temperature. As the temperature was raised to body temperature (37 °C), the dispersion rapidly (∼170 s) underwent sol-gel transition with excellent gel modulus (G' ≈ 6.5 kPa) in 20 min. PU dispersions with a solid content of 25-30% could be easily mixed with cells in sol state, extruded by a 3D printer, and deposited layer by layer as a gel. Cells remained alive and proliferating in the printed hydrogel scaffold. We expect that the development of novel thermoresponsive PU system can be used as smart injectable hydrogel and applied as a new type of bio-3D printing ink.
authors.affiliation: Institute of Polymer Science and Engineering, National Taiwan University , No. 1, Sec. 4 Roosevelt Road, Taipei 10617, Taiwan, R.O.C.
authors.forename: Yi-Chun
authors.initials: YC
authors.lastname: Tsai
authors.affiliation: Institut Europeen des Membranes, Universite Montpellier , Montpellier 34090, France.
authors.forename: Suming
authors.initials: S
authors.lastname: Li
authors.affiliation: Department of Materials Science and Engineering, National Taiwan University of Science and Technology , Taipei 106, Taiwan, R.O.C.
authors.forename: Shiaw-Guang
authors.initials: SG
authors.lastname: Hu
authors.affiliation: Institute of Polymer Science and Engineering, National Taiwan University , No. 1, Sec. 4 Roosevelt Road, Taipei 10617, Taiwan, R.O.C.
authors.forename: Wen-Chi
authors.initials: WC
authors.lastname: Chang
authors.affiliation: National Synchrotron Radiation Research Center , Hsinchu City 300, Taiwan, R.O.C.
authors.forename: U-Ser
authors.initials: US
authors.lastname: Jeng
authors.affiliation: Institute of Polymer Science and Engineering, National Taiwan University , No. 1, Sec. 4 Roosevelt Road, Taipei 10617, Taiwan, R.O.C.
authors.forename: Shan-hui
authors.initials: SH
authors.lastname: Hsu
mesh_terms: D001672:Biocompatible Materials / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D006801:Humans; D011108:Polymers / Q000737:chemistry / Q000494:pharmacology; D011140:Polyurethanes / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology; D066330:Printing, Three-Dimensional; D053838:Scattering, Small Angle; D013501:Surface-Active Agents / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology; D013696:Temperature
chemical_list: D001672:Biocompatible Materials; D011108:Polymers; D011140:Polyurethanes; D013501:Surface-Active Agents
keywords: 3D-printing ink; amphiphilic block copolymer; hydrogel; small-angle X-ray scattering (SAXS); waterborne polyurethane