Fabrication and morphology control of electrospun poly(γ-glutamic acid) nanofibers for biomedical applications

We report the fabrication of water-stable electrospun γ-polyglutamic acid (γ-PGA) nanofibers with morphology control for biomedical applications. In this study, the processing variables including polymer concentration, flow rate, applied voltage, collection distance, and ambient humidity were systematically optimized to generate uniform γ-PGA nanofibers with a smooth morphology. By changing the trifluoroacetic acid concentration in the electrospinning solution, the diameter of the γ-PGA nanofibers can be controlled within the range of 186-603 nm. To render the γ-PGA nanofibers with good water stability, cystamine was employed as a crosslinking agent to amidate the carboxyl groups of γ-PGA. Furthermore, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide colorimetric assay in conjunction of cell morphology observation reveals that the obtained γ-PGA nanofibers have an excellent biocompatibility to promote the cell adhesion and proliferation. We anticipate that the fabricated electrospun γ-PGA nanofibers with controllable morphology and good water stability may find extensive applications in future development of tissue engineering scaffold materials, drug delivery systems, environmental remediation, and sensing.