Hsu Shan-Hui, Chen Cheng-Wei, Hung Kun-Che, Tsai Yi-Chun, Li Suming
Institute of Polymer Science and Engineering, National Taiwan University, Taipei 10617, Taiwan.
Institut Europeen des Membranes, UMR CNRS 5635, Universite de Montpellier, Place Eugene Bataillon, 34095 Montpellier Cedex 5, France.
Polymers (Basel). 2016 Jul 5;8(7):252. doi: 10.3390/polym8070252.
Waterborne polyurethane (PU) based on poly(ε-caprolactone) (PCL) diol and an amphiphilic polylactide-poly(ethylene glycol) (PLA-PEG) diblock copolymer was synthesized. The molar ratio of PCL/PLA-PEG was 9:1 with different PLA chain lengths. The PU nanoparticles were characterized by dynamic light scattering (DLS), small angle X-ray scattering (SAXS) and rheological analysis. The water contact angle measurement, infrared spectroscopy, wide angle X-ray scattering (WAXS), thermal and mechanical analyses were conducted on PU films. Significant changes in physio-chemical properties were observed for PUs containing 10 mol % of amphiphilic blocks. The water contact angle was reduced to 12°⁻13°, and the degree of crystallinity was 5%⁻10%. The PU dispersions underwent sol-gel transition upon the temperature rise to 37 °C. The gelation time increased as the PLA chain length increased. In addition, the fractal dimension of each gel was close to that of a percolation cluster. Moreover, PU4 with a solid content of 26% could support the proliferation of human mesenchymal stem cells (hMSCs). Therefore, thermo-responsive hydrogels with tunable properties are promising injectable materials for cell or drug delivery.
合成了基于聚（ε-己内酯）（PCL）二醇和两亲性聚乳酸-聚乙二醇（PLA-PEG）二嵌段共聚物的水性聚氨酯（PU）。PCL/PLA-PEG的摩尔比为9:1，具有不同的PLA链长。通过动态光散射（DLS）、小角X射线散射（SAXS）和流变学分析对PU纳米颗粒进行了表征。对PU薄膜进行了水接触角测量、红外光谱、广角X射线散射（WAXS）、热分析和力学分析。观察到含有10 mol%两亲性嵌段的PU的物理化学性质有显著变化。水接触角降低到12°⁻13°，结晶度为5%⁻10%。PU分散体在温度升至37°C时发生溶胶-凝胶转变。凝胶化时间随着PLA链长的增加而增加。此外，每个凝胶的分形维数接近渗流簇的分形维数。此外，固含量为26%的PU4能够支持人间充质干细胞（hMSCs）的增殖。因此，具有可调性质的热响应水凝胶是用于细胞或药物递送的有前景的可注射材料。
