Type I collagen – poly(vinyl alcohol) electrospun nanofibers: FTIR study of the collagen helical structure preservation

Electrospinning of type I collagen (Col_1) has shown major issues regarding material structure. Researchers have reported complete hydrolysis of this protein during the electrospinning, especially when fluorinated solvents are used. Solvents such as HFIP, THF, etc. generate fibers with Col_1 structureless ordered, and fewer α bonds of collagen, characteristics that usually describe the sub-product of collagen named gelatin. Therefore, this work aimed to investigate the use of a new bicomponent solvent system based on glacial acetic acid and ultrapure water (1:1 volumetric ratio) to preserve the main structure of collagen during solubilization and electrospinning processes. Monolithic poly(vinyl alcohol) (PVA) and Col_1/PVA fibers were obtained via electrospinning, using a 1:1 Col_1:PVA mass ratio. Col_1/PVA fibers were produced with an average diameter of 172.8 nm varying the flow rate and voltage. Evaluation of the triple helix structure of the collagen electrospun fibers by ATR-FTIR showed a high percentage of this structure which was confirmed by DSC. This denotes that the methodology used in this work was satisfactory for producing type I collagen-based nanofibers with high content of triple helix structure.