Mechanically switchable polymer fibers for sensing in biological conditions.
The area of in vivo sensing using optical fibers commonly uses materials such as silica and polymethyl methacrylate, both of which possess much higher modulus than human tissue. The mechanical mismatch between materials and living tissue has been seen to cause higher levels of glial encapsulation, scarring, and inflammation, leading to failure of the implanted medical device. We present the use of a fiber made from polyvinyl alcohol (PVA) for use as an implantable sensor as it is an easy to work with functionalized polymer that undergoes a transition from rigid to soft when introduced to water. This ability to switch from stiff to soft reduces the severity of the immune response. The fabricated PVA fibers labeled with fluorescein for sensing applications showed excellent response to various stimuli while exhibiting mechanical switchability. For the dry fibers, a tensile storage modulus of 4700 MPa was measured, which fell sharply to 145 MPa upon wetting. The fibers showed excellent response to changing pH levels, producing values that were detectable in a range consistent with those seen in the literature and in proposed applications. The results show that these mechanically switchable fibers are a viable option for future sensing applications.
Virginia Tech, Department of Materials Science and Engineering, Blacksburg, Virginia, United States.
Sean
S
McMillan
Virginia Tech, Department of Materials Science and Engineering, Blacksburg, Virginia, United States.
Chris
C
Rader
Massachusetts Institute of Technology, Department of Chemical Engineering, Cambridge, Massachusetts, United StatescMassachusetts General Hospital, Center for Engineering in Medicine, Harvard Medical School, Boston, Massachusetts, United States.
Mehdi
M
Jorfi
Virginia Tech, Department of Materials Science and Engineering, Blacksburg, Virginia, United States.
Gary
G
Pickrell
Virginia Tech, Department of Materials Science and Engineering, Blacksburg, Virginia, United States.
E Johan
EJ
Foster
D001672:Biocompatible Materials / Q000737:chemistry*; D006801:Humans; D011108:Polymers / Q000737:chemistry*; D011142:Polyvinyl Alcohol / Q000737:chemistry*; D019736:Prostheses and Implants / Q000592:standards*
D001672:Biocompatible Materials; D011108:Polymers; D011142:Polyvinyl Alcohol