One‐Step Production of Polymeric Microtubes by Co‐electrospinning

Dror, Yael; Salalha, Wael; Avrahami, Ron; Zussman, Eyal; Yarin, Alexander L.; Dersch, Roland; Greiner, Andreas; Wendorff, Joachim H.

doi:10.1002/smll.200600536

Cited by 217 publications

(227 citation statements)

References 45 publications

(37 reference statements)

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“…To estimate the actual evaporation time, a tubular nanofiber, [54][55][56] filled with solvent, is examined. This system can be considered as an extreme case of the model discussed 47 by Guenther et al 36 Use of such tubular nanofibers enables in situ tracking of the kinetics of solvent evaporation through the nanofiber shell.…”

Section: Postprocesses Relaxation In Electrospun Nanofibersmentioning

confidence: 99%

Electrospun polymer nanofibers: Mechanical and thermodynamic perspectives

Arinstein

Zussman

2011

J Polym Sci B Polym Phys

137

103

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This article reviews and discusses some open problems concerning polymer materials of reduced sizes and dimensions. Such objects exhibit exceptional physical properties when compared with their macroscopic counterparts. More specifically, abrupt increases in polymer nanofiber elastic modulus have been observed when diameters drop below a certain value. In addition, temperature dependence of elastic modulus is highly influenced by fiber diameter. Mechanical (macroscopic) analyses have failed to provide satisfactory explanations for the mechanisms ruling such features, calling for detailed microscopic examination of the systems in question. A hypothesis bridging the current knowledge gaps is presented. The key element of this hypothesis is based on confinement of the supermolecular microstructure of polymer nanofibers and its dominant role in the deformation process. This suggestion challenges the commonly held view suggesting that surface effects are the most significant parameters impacting mechanical and thermodynamic nanofiber behaviors. The review will focus on the mechanical and thermodynamic properties of electrospun polymer nanofibers, selected as representatives of nanoscale polymer objects.

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Section: Postprocesses Relaxation In Electrospun Nanofibersmentioning

confidence: 99%

Electrospun polymer nanofibers: Mechanical and thermodynamic perspectives

Arinstein

Zussman

2011

J Polym Sci B Polym Phys

137

103

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“…[26][27][28] It has been applied in controlling secondary structures of nanofibers, encapsulating drugs or biological agents into polymeric nanofibers, fabricating polymeric microtubes, preparing nanofibers from materials that lack filamentforming properties, and enclosing functional liquids within the fiber matrix. [29][30][31][32][33] Through modifications, nanofiber diameters can be manipulated for controlling the size of self-assembled nanoparticles, preparing ultrafine structures from concentrated polymer solutions, and improving nanofiber quality systematically. [34][35][36][37][38][39] Based on the above knowledge, we report on the formation of a novel solid dispersion in the form of coresheath nanofibers produced using a coaxial electrospinning process.…”

Section: Introductionmentioning

confidence: 99%

Solid dispersions in the form of electrospun core-sheath nanofibers

Yu¹,

Zhu²,

Branford-White³

et al. 2011

IJN

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Background:The objective of this investigation was to develop a new type of solid dispersion in the form of core-sheath nanofibers using coaxial electrospinning for poorly water-soluble drugs. Different functional ingredients can be placed in various parts of core-sheath nanofibers to improve synergistically the dissolution and permeation properties of encapsulated drugs and to enable drugs to exert their actions. Methods: Using acyclovir as a model drug, polyvinylpyrrolidone as the hydrophilic filamentforming polymer matrix, sodium dodecyl sulfate as a transmembrane enhancer, and sucralose as a sweetener, core-sheath nanofibers were successfully prepared, with the sheath part consisting of polyvinylpyrrolidone, sodium dodecyl sulfate, and sucralose, and the core part composed of polyvinylpyrrolidone and acyclovir. Results: The core-sheath nanofibers had an average diameter of 410 ± 94 nm with a uniform structure and smooth surface. Differential scanning calorimetry and x-ray diffraction results demonstrated that acyclovir, sodium dodecyl sulfate, and sucralose were well distributed in the polyvinylpyrrolidone matrix in an amorphous state due to favoring of second-order interactions. In vitro dissolution and permeation studies showed that the core-sheath nanofiber solid dispersions could rapidly release acyclovir within one minute, with an over six-fold increased permeation rate across the sublingual mucosa compared with that of crude acyclovir particles. Conclusion: The study reported here provides an example of the systematic design, preparation, characterization, and application of a novel type of solid dispersion consisting of multiple components and structural characteristics.

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“…8D illustrates the conditions around a bacterium cell inside a cross-linked FDMA fiber. In contrast to the fibers reported previously (13)(14)(15)(16)(17), which are composed of a water-insoluble polymer shell around a hollow core formed by dissolution of a hydrophilic component, the fibers discussed here are formed around the bacterium from a uniform hydrophilic polymer solution. When immersed in water, the crosslinks prevent the fibers from dissolving and lead to the formation of a mesh-like network of the swollen polymer within a short time (Fig.…”

Section: Resultsmentioning

confidence: 65%

“…Previous studies have reported the encapsulation of biological molecules such as enzymes, proteins, or animal cells in polymer fibers by co-electrospinning (13)(14)(15)(16)(17). In this process, 2 different solutions are spun simultaneously using a spinneret with 2 coaxial capillaries to produce core/shell fibers.…”

mentioning

confidence: 99%

Engineering of bio-hybrid materials by electrospinning polymer-microbe fibers

Liu

Rafailovich

Malal

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

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Although microbes have been used in industrial and niche applications for several decades, successful immobilization of microbes while maintaining their usefulness for any desired application has been elusive. Such a functionally bioactive system has distinct advantages over conventional batch and continuous-flow microbial reactor systems that are used in various biotechnological processes. This article describes the use of polyethylene oxide 99-polypropylene oxide 67-polyethylene oxide99 triblock polymer fibers, created via electrospinning, to encapsulate microbes of 3 industrially relevant genera, namely, Pseudomonas, Zymomonas, and Escherichia. The presence of bacteria inside the fibers was confirmed by fluorescence microscopy and SEM. Although the electrospinning process typically uses harsh organic solvents and extreme conditions that generally are harmful to bacteria, we describe techniques that overcome these limitations. The encapsulated microbes were viable for several months, and their metabolic activity was not affected by immobilization; thus they could be used in various applications. Furthermore, we have engineered a microbe-encapsulated cross-linked fibrous polymeric material that is insoluble. Also, the microbe-encapsulated active matrix permits efficient exchange of nutrients and metabolic products between the microorganism and the environment. The present results demonstrate the potential of the electrospinning technique for the encapsulation and immobilization of bacteria in the form of a synthetic biofilm, while retaining their metabolic activity. This study has wide-ranging implications in the engineering and use of novel bio-hybrid materials or biological thin-film catalysts.biofilm ͉ cross-linking ͉ immobilization ͉ microbial ͉ Zymomonas

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One‐Step Production of Polymeric Microtubes by Co‐electrospinning

Cited by 217 publications

References 45 publications

Electrospun polymer nanofibers: Mechanical and thermodynamic perspectives

Electrospun polymer nanofibers: Mechanical and thermodynamic perspectives

Solid dispersions in the form of electrospun core-sheath nanofibers

Engineering of bio-hybrid materials by electrospinning polymer-microbe fibers

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