Electrospinning of fibrous polymer scaffolds using positive voltage or negative voltage: a comparative study

Abstract

Electrospinning of fibrous tissue engineering scaffolds has been traditionally conducted using positive voltages. In the current study, positive voltage (PV) electrospinning and negative voltage (NV) electrospinning were investigated for forming fibrous membranes of poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV). In both PV-electrospinning and NV-electrospinning, the fiber diameter generally increased with increasing needle inner diameter and PHBV concentration but decreased with increasing working distance. The use of a conductivity-enhancing surfactant, benzyl triethylammonium chloride (BTEAC), significantly reduced PHBV fiber diameters from the micron scale to the sub-micron scale. Interestingly, with increasing applied voltage, the fiber diameter increased for PV-electrospinning but decreased for NV-electrospinning. The PV-electrospun fibrous membranes from solutions without BTEAC (PVEfm) and with BTEAC (PVEfm-B) and NV-electrospun membranes from solutions without BTEAC (NVEfm) and with BTEAC (NVEfm-B) were characterized in terms of their structure, wettability, thermal properties and tensile properties. Both PVEfm and NVEfm exhibited similar water contact angles (∼104°) but the contact angle of PVEfm-B or NVEfm-B was not measurable. The elongation at break of PVEfm-B or NVEfm-B was significantly higher than that of PVEfm or NVEfm. Using NV-electrospinning or a combination of NV- and PV-electrospinning may be very useful for developing suitable scaffolds for tissue engineering applications.

Transient charge-masking effect of applied voltage on electrospinning of pure chitosan nanofibers from aqueous solutions

“…Although cathodic electrospinning has been reported and discussed in several studies [25][26][27][28], no mention of its advantage over anodic electrospinning has been made. In this work, we demonstrated the effectiveness of cathodic electrospinning and the importance of voltage polarity in the electrospinning process.…”

Characterizing the Reproducibility of the Properties of Electrospun Poly(d,l-Lactide-Co-Glycolide) Scaffolds for Tissue-Engineered Blood Vessel Mimics

“…Fiber diameter is a common characteristic to manipulate in the electrospinning process because smaller fibers resemble the nanofibrous biological ECM, as mentioned earlier 12 . Parameters that greatly influence fiber diameter include solution concentration [60][61][62] , applied voltage [61][62][63] , flow rate 60,62,63 , gap distance 62,63 , and environment 64,65 . These are discussed in detail in the following sections.…”

“…Higher concentrations create higher viscosities, which stops fiber formation. It has also been shown that increasing the concentration increases the fiber diameter and results in more uniform fibers [60][61][62]66 .…”

“…Additionally, an increase of voltage results in a decrease of fiber diameter with no change in the pore size distribution 64 . It has been postulated that the reduction in fiber diameter can be attributed to an increased acceleration of the polymer jet which caused further charge repulsion and thinning as the jet traveled toward the collector 62,63,66 . Different solutions have been shown to have the opposite effect;…”

“…This dependence is a consequence of evaporation rate, deposition time, and instability interval. It has been demonstrated that shorter distances result in wet fibers, bead formation, and flat fibers instead of round 62,64 . An increase in gap distance results in a reduction in fiber diameter and gives the solvent more time to evaporate before landing on the collecting mandrel 63,66 .…”