Implication of stable jet length in electrospinning for collecting well-aligned ultrafine PLLA fibers

Zhang

Macromolecular Bioscience

et al. 2017

Self Cite

Electrospun natural-synthetic composite nanofibers, which possess favorable biological and mechanical properties, have gained widespread attention in tissue engineering. However, the development of biomimetic nanofibers of hybrids remains a huge challenge due to phase separation of the polymer blends. Here, aqueous sodium hydroxide (NaOH) solution is proposed to modulate the miscibility of a representative natural-synthetic hybrid of gelatin (GT) and polycaprolactone (PCL) for electrospinning homogeneous composite nanofibers. Alkali-doped GT/PCL solutions and nanofibers examined at macroscopic, microscopic, and internal molecular levels demonstrate appropriate miscibility of GT and PCL after introducing the alkali dopant. Particularly, homogeneous GT/PCL nanofibers with smooth surface and uniform diameter are obtained when aqueous NaOH solution with a concentration of 10 m is used. The fibers become more hydrophilic and possess improved mechanical properties both in dry and wet conditions. Moreover, biocompatibility experiments show that stem cells adhere to and proliferate better on the alkali-modified nanofibers than the untreated one. This study provides a facile and effective approach to solve the phase separation issue of the synthetic-natural hybrid GT/PCL and establishes a correlation of compositionally and morphologically homogeneous composite nanofibers with respect to cell responses.

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Alkali‐Mediated Miscibility of Gelatin/Polycaprolactone for Electrospinning Homogeneous Composite Nanofibers for Tissue Scaffolding

Zhang

Macromolecular Bioscience

et al. 2017

Self Cite

“…25,26 Briefly, PLLA was dissolved in dichloromethane (DCM) under stirring at room temperature for 12 h to obtain a 3 wt% polymer solution. 25,26 Briefly, PLLA was dissolved in dichloromethane (DCM) under stirring at room temperature for 12 h to obtain a 3 wt% polymer solution.…”

Section: Preparation Of Aligned Electrospun Plla Fibersmentioning

confidence: 99%

Engineering aligned electrospun PLLA microfibers with nano-porous surface nanotopography for modulating the responses of vascular smooth muscle cells

et al. 2015

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In tissue engineering research, aligned electrospun ultrafine fibers have been shown to regulate cellular alignment and relevant functional expression, but the imposed effect of individual fiber surface nanotopography on cell behaviour has not been examined closely. This work investigates the impact of superimposing a nano-pore feature atop individual fiber surfaces on the responsive behaviour of human vascular smooth muscle cells (vSMCs) for blood vessel tissue engineering. Well-aligned ultrafine poly(L-lactic acid) (PLLA) microfibers with an average fiber diameter of ca. 1.6 mm were fabricated by using a novel stable jet electrospinning (SJES) method. Ellipse-shaped nano-pores with varied aspect ratios (defined as longto-short axis ratio) of 2.7-3.9, corresponding to a surface nano-roughness in the range of 54.8-110.0 nm, were in situ generated onto individual fiber surfaces by varying ambient humidity from 45% to 75% during the SJES process. The presence of elliptical nano-pores on fiber surfaces affected the characteristic anisotropic wettability of the aligned PLLA fibers and contributed to greater protein adsorption (up to 17.59 mg mg À1 ). A 7 day in vitro assessment of human umbilical arterial SMCs cultured on these aligned nano-porous fiber substrates indicated that cellular responses were in close correlation with the elliptical nano-pore feature. A pronounced fiber surface nanotopography was superior in soliciting favorable cellular responses, leading to enhanced cell attachment, proliferation, alignment, expression of the vascular matrix proteins and maintenance of a contractile phenotype. This study thus suggests that introduction of an elliptical nano-pore feature to the aligned microfiber surfaces could provide additional dimensionality of topographical cues to modulate the vSMC responses when using the aligned electrospun ultrafine fibers for engineering vascular constructs.

J of Applied Polymer Sci

“…With the development of electrospinning technology, Stable Jet Electrospinning (SJES) has emerged as a fascinating approach for fabricating individual fibers or well‐aligned unidirectional fiber arrays by using a rotating cylindrical collector . The characteristic whipping motion of the liquid jet can be suppressed or eliminated by introducing an auxiliary electrode, using special solvents or formulating the viscoelasticity of spinning dopes . Carnell et al .…”

Section: Introductionmentioning

confidence: 99%

“…Zhou et al . studied the influence of some pivotal parameters including solvent, polymer molecular weight, and concentration on the property of stable jet when fabricating poly(L‐lactic acid) (PLLA) fibers . Experimental results revealed that the high viscoelasticity of polymer solution as well as low solvent dielectric constant should be the major contributor to the formation of single linear jet without bending instability.…”

Section: Introductionmentioning

confidence: 99%

Continuous aligned poly(meta‐phenylene isophthalamide) fibers via stable jet electrospinning

Chen

Weng

2016

Continuous aligned poly(meta-phenylene isophthalamide) (PMIA) fibers are first fabricated by Stable Jet Electrospinning (SJES) with a collection distance of 15 cm. The unfolded length of every single fiber is calculated to be several hundred to several thousand meters. Morphology analysis by field emission scanning electron microscopy (FE-SEM) shows that these fibers are well arranged and uniformly distributed and their average fiber diameters decrease gradually with increasing collection speed. The effects of ambient temperature and humidity on the duration of stable jet are also discussed. Moderate temperatures and humidity are preferred for fabricating PMIA fibers with ultra-long size. Besides, the changes of the thermal and crystalline properties of PMIA fibers are also investigated. The significant decline in crystallinity should be responsible for its decreased thermal property. Further improvements to its thermal and crystalline performance must be given consideration in future applications. V C 2016 Wiley Periodicals, Inc. J.Appl. Polym. Sci. 2016, 133, 43690.