Abstract
Poly-γ-glutamic acid (γ-PGA) is a natural polymer that is widely recognized as a component in the viscous
filaments of fermented soybean (natto). γ-PGA is known for its superior biodegradability, biocompatibility and water
retention characteristics. Crosslinked γ-PGA is commonly used as hydrogel, but it is not used in the fiber form because
it is soluble in water. In this study, we demonstrate the use of γ-PGA-Na with Polyethylene Glycol Diglycidyl Ether
(PEGDE) for crosslinking agent to produce water insoluble γ-PGA nanofibers by electrospinning. The presence of
PEGDE in electrospun γ-PGA and the crosslinking reaction of the epoxy group with γ-PGA carboxyl groups were
confirmed by FTIR. We confirmed with the pulse NMR the existence of the component of long relaxation time which
was not ingredient in γ-PGA. Reflecting the properties of γ-PGA, this γ-PGA/PEGDE nanofiber web showed high level
of water absorption capability. The γ-PGA/PEGDE nanofiber web had the tensile properties of a level equal to skin, and
elastic recovery characteristics. This nanofiber became strong by adding hydrochloric acid or more safety acid of citric
acid in electrospinning solution.
