Solvent Retention in Electrospun Fibers Affects Scaffold Mechanical Properties

Abstract

Electrospinning is a robust material fabrication method allowing for fine control of mechanical, chemical, and functional properties in scaffold manufacturing. Electrospun fiber scaffolds have gained prominence for their potential in a variety of applications such as tissue engineering and textile manufacturing, yet none have assessed the impact of solvent retention in fibers on the scaffold’s mechanical properties. In this study, we hypothesized that retained electrospinning solvent acts as a plasticizer, and gradual solvent evaporation, by storing fibers in ambient air, will cause significant increases in electrospun fiber scaffold brittleness and stiffness, and a significant decrease in scaffold toughness. Thermogravimetric analysis indicated solvent retention in PGA, PLCL, and PET fibers, and not in PU and PCL fibers. Differential scanning calorimetry revealed that polymers that were electrospun below their glass transition temperature (Tg) retained solvent and polymers electrospun above Tg did not. Young’s moduli increased and yield strain decreased for solventretaining PGA, PLCL, and PET fiber scaffolds as solvent evaporated from the scaffolds over a period of 14 days. Toughness and failure strain decreased for PGA and PET scaffolds as solvent evaporated. No significant differences were observed in the mechanical properties of PU and PCL scaffolds that did not retain solvent. These observations highlight the need to consider solvent retention following electrospinning and its potential effects on scaffold mechanical properties.

Electrospun Poly(ethylene Terephthalate)/Silk Fibroin Composite for Filtration Application

“…The solvents in this study had to be selected regarding electrospinnability. PET has been already electrospun from a trifluoroacetic acid (TFA), a mixture of TFA/DCM [ 44 , 66 , 67 ] in various portions or from HFIP and HFIP/DCM [ 33 , 68 ]. In the case of silk fibroin, it has been proven many times that the SF could be electrospun from aqueous solutions only with the aid of an auxiliary polymer [ 69 , 70 ]; however, it was successfully electrospun from formic acid (FA), TFA, and HFIP [ 58 , 70 , 71 ].…”

Electrospun Bioresorbable Membrane Eluting Chlorhexidine for Dental Implants

“…It was reported that electrospun PGA fibers retained a higher amount of HFIP than that measured with electrospun PLC fibers [19]. HFIP is progressively removed from PLC fibers until complete evaporation, which is not the case for PGA electrospun fibers, where remaining solvent was still detected after 14 days [19]. Moreover, PCL has no significant interaction with HFIP (2,3), whereas PLLA has an affinity [20].…”

“…Solvent retention is a critical property, due to the toxicity of the solvent used during electrospinning [19]. It was reported that electrospun PGA fibers retained a higher amount of HFIP than that measured with electrospun PLC fibers [19].…”

“…Solvent retention is a critical property, due to the toxicity of the solvent used during electrospinning [19]. It was reported that electrospun PGA fibers retained a higher amount of HFIP than that measured with electrospun PLC fibers [19]. HFIP is progressively removed from PLC fibers until complete evaporation, which is not the case for PGA electrospun fibers, where remaining solvent was still detected after 14 days [19].…”

Acrylonitrile and Pullulan Based Nanofiber Mats as Easily Accessible Scaffolds for 3D Skin Cell Models Containing Primary Cells

“…Electrospun nanofibers P(AN-MA) showed all the characteristic peaks of P(AN-MA), in particular the distinctive nitrile (C≡N) vibration at 2243 cm −1 and the CH2 bending vibration at 1454 cm −1 . The characteristic peaks at 1734 cm −1 (marked with a triangle) can be associated with the (C=O) stretching vibration of the methacrylic acid functional groups [34]. We investigated to which extent sterilization would affect the P(AN-MA) nanofibers, since sterilization may alter the properties of electrospun nanofibers [35].…”