Shape-Memory Nanofiber Meshes with Programmable Cell Orientation

• Main Authors: Eri Niiyama, Kanta Tanabe, Koichiro Uto, Akihiko Kikuchi, Mitsuhiro Ebara
• Format: Article
• Language: English
• Published: MDPI AG 2019-03-01
• Series: Fibers
• Subjects: shape memory nanofiber; shape memory polymer; poly(ε-caprolactone); melting temperature; cell orientation; polyurethane
• Online Access: http://www.mdpi.com/2079-6439/7/3/20

In this work we report the rational design of temperature-responsive nanofiber meshes with shape-memory properties. Meshes were fabricated by electrospinning poly(ε-caprolactone) (PCL)-based polyurethane with varying ratios of soft (PCL diol) and hard [hexamethylene diisocyanate (HDI)/1,4-butanediol (BD)] segments. By altering the PCL diol:HDI:BD molar ratio both shape-memory properties and mechanical properties could be readily turned and modulated. Though mechanical properties improved by increasing the hard to soft segment ratio, optimal shape-memory properties were obtained using a PCL/HDI/BD molar ratio of 1:4:3. Microscopically, the original nanofibrous structure could be deformed into and maintained in a temporary shape and later recover its original structure upon reheating. Even when deformed by 400%, a recovery rate of >89% was observed. Implementation of these shape memory nanofiber meshes as cell culture platforms revealed the unique ability to alter human mesenchymal stem cell alignment and orientation. Due to their biocompatible nature, temperature-responsivity, and ability to control cell alignment, we believe that these meshes may demonstrate great promise as biomedical applications.