Polyester Nanofibers Research Articles

Silk fibroin incorporated electrospun aliphatic polyester nanofiber scaffolds with excellent dimensional stability and cytocompatibility

Poly (lactide-co-glycolide) (PLGA) has been extensively utilized to fabricate electrospun fibers for tissue engineering scaffolds due to its good biocompatibility and biodegradability. However, such scaffolds in biological media shrink and distort severely, which is undesired for practical application. In this study, a silk fibroin incorporated electrospun aliphatic polyester nanofiber scaffold (PLGA/PCL/SF) was developed via facile one-step electrospinning, with PLGA as the substrate and incorporating polycaprolactone (PCL) and silk fibroin (SF). The resulting scaffold exhibited fine fibers and water absorbency. Particularly, the addition of SF into scaffolds improved the water adsorption ability, and that of PCL effectively prevented scaffold shrinkage behaviors. In vitro degradation analyses showed that it was accelerating for the obtained scaffolds with SF added, without any undesirable acidic environment induced. Additionally, the PLGA/PCL/SF scaffold exhibited the most promising result in cell proliferation, presenting a valuable insight into the design of tissue engineering scaffolds.

Green preparation of electrically conductive solution blow spun nanofibers from recycled polyethylene terephthalate via plasma-assisted oxidation-reduction.

Simple and green strategy was described for the development of multifunctional polyester nanofibers (PNFs). Solution blow spinning (SBS) technology was applied to in situ immobilize nanocomposites of polyaniline (PANi) and silver nanoparticles (AgNPs) into plasma-treated polyester nanoscaled fibers prepared. The polyester nanofibers were prepared from recycled polyethylene terephthalate waste, which was exposed plasma-curing and a REDOX reaction in the presence of AgNO3, aniline, and CH3COONH4. Plasma-catalyzed oxidative polymerization of aniline to polyaniline together with a reductive process of Ag+ to silver nanoparticles led to their enduring insoluble dispersion into the surface of polyester nanofibers. By taking the advantage of the PANi oxidation, AgNPs were precipitated from an aqueous medium of AgNPs. The morphological properties were investigated by various analytical techniques. The polyester fiber diameter was determined in the range of 450-650nm. In addition, transmission electron microscopy (TEM) and scanning electron microscopy (SEM) were utilized to examine AgNPs, demonstrating diameters of 4-20nm. The plasma-uncured AgNPs/PANi immobilized nanofibrous film displayed weak absorption bands at 399nm and 403nm upon increasing the concentration of AgNPs. On the other hand, the plasma-cured AgNPs/PANi immobilized nanofibers displayed strong absorption bands at 526nm and 568nm upon increasing the concentration of AgNPs. The AgNP-induced antimicrobial performance and the PANi-induced electrically conductivity were explored. The prepared PNFs showed high UV protection.

Manipulating hydrophobicity of polyester nanofiber mats with egg albumin to enhance cell interactions

AbstractA hybrid of poly‐l‐lactic acid (PLA) and poly‐ε‐caprolactone (PCL) system was designed using hydrophilic generally regarded as safe (GRAS) protein, egg albumin (EA), and fabricated as nanofiber mats (NM) to facilitate improved cell interactions and functionality. Our studies include, preparation and analysis of physicochemical properties of NM. Surface morphology of NM was smooth with the diameter ranging from 250 to 400 nm. The contact angle of NM decreased from 80 to 45° with the increase in EA concentration. The rate and extent of swelling was increased 3‐folds with the addition of EA. Release studies of NM showed maximum amount of MTz was released with the increase in MTz concentration (>85%). The MTz interaction with EA and structure stability of EA was confirmed from fluorescence and circular dichroism studies. NM showed increase in inhibition of bacterial growth of Staphylococcus aureus and Escherichia coli with the increase in MTz concentration. Cell viability of the NM was >80% and also, the cell proliferation increased as EA content increased. NM hemolytic activity was less than 5% suggesting compatibility. Hence, results concluded that EA had regulated hydrophobicity, promoted cell interactions, and proliferation and therefore, NM is considered safe for tissue regeneration.

Recycled polyester nanofiber as a reservoir for essential oil release

AbstractThe importance of creating sustainable alternatives for products that can be easily recyclable, such as, poly (ethylene terephthalate) (PET), is not new, being textile fibers the product of greatest interest. The objective of this work is to propose a recycling alternative for PET bottles for fiber production as a reservoir of essential oils for aromatherapy applications. The fibers were obtained via coaxial and dual‐jet electrospinning techniques. The material used in the impregnation and release of peppermint oil was PET originating from disposable bottles. The release of oil from the electrospun fibers was quantified by UV–vis spectroscopy. For the fibers produced by dual‐jet electrospinning the cumulative release of peppermint reached around 70% after 30 days. The sample obtained by coaxial electrospinning had a core‐shell structure and the amount of oil released was 33% after 30 days. In this investigation, a less aggressive process was introduced, making the electrospinning of PET a viable technique for essential oil impregnation. Dual‐jet as well as coaxial electrospinning showed slower release than values reported in the literature. Thus, a procedure with more favorable working conditions was developed, making the process more feasible and serving as an alternative for recycling PET bottles to produce functional textiles.

Pendant Functionalized Polyester Nanofibers with Dual Cargo Release.

Common polymeric biomaterials lack the ability to control the release of multiple bioactive compounds due to their inherent lack of functionality. These materials often require additional components or complicated fabrication techniques to achieve the separate release profiles desired for wound healing and tissue engineering applications. This prevents many biomaterials from being translated to the clinic, because the complexity of the wound environment necessitates temporal control of multiple additives for effective healing. Electrospun nanofibers comprised of a functional polymer would allow for separate release profiles of multiple bioactive compounds through covalent conjugation or tuning noncovalent interactions. In this work, two fluorescent dyes as model drugs were released from functional polyester electrospun mats. Two mats were fabricated: one in which both dyes were blended into the electrospinning solution and one in which one dye was blended and the other was covalently conjugated to the polymer. Average fiber diameters were determined using scanning electron microscopy, while fluorescence microscopy showed the presence of both dyes in the fibers. Dye release was tracked using UV-vis spectroscopy by comparing measured values to standard curves. Finally, degradation of the mats was tracked using gel permeation chromatography. With this functional polyester platform, distinct release profiles were achieved for two model drugs. Not only does the release of two model drugs show potential for the future use of this polymer platform in the applications of wound healing and tissue engineering but also the ability to incorporate several distinct conjugation chemistries is of great benefit.

Laden Nanofiber Capsules for Local Malignancy Chemotherapy.

In contrast to systemic chemotherapy, the local administration of chemotherapeutics potentially optimizes their accumulation in the tumor tissues and alleviates the associated systemic toxicity. However, the lack of control over the release of encapsulated drugs and their degradation represents a major challenge for local drug delivery systems. In this study, we developed a series of epirubicin (EPI)-loaded poly(ε-caprolactone)/poly(lactide-co-glycolide) (PCL/PLGA) nanofiber capsules with adjustable rates of drug release and degradation for local malignancy chemotherapy. The core-sheath PCL/PLGA nanofiber capsules containing 15.0 or 25.0 wt% of PCL in the sheath and 0, 5.0, or 10.0 wt% of EPI in the core were produced by emulsion electrospinning technology. The EPI release and degradation of the nanofiber capsules could be accelerated by decreasing the PCL content in the sheath. More importantly, the EPI-loaded PCL/PLGA nanofiber capsules effectively inhibited the growth of tumor cells in vitro and in vivo. Moreover, none of the laden nanofiber capsules caused apparent systemic toxicity. Hence, the cytostatic-loaded electrospun polyester nanofiber capsules displayed controlled drug release and degradation, along with satisfactory antitumor properties, indicating their great potential in local malignancy chemotherapy.

Fabrication of fibrous microfiltration membrane by pore filling of nanofibers into poly(ethylene terephthalate) nonwoven scaffold

A nanofibrous microfiltration membrane with high flux, low pressure drop, and high retention capacity was fabricated by pore filling of copolyetherester nanofibers (low-melting-point polyester; melting point of 110℃) into a poly(ethylene terephthalate) nonwoven scaffold. Short low-melting-point polyester nanofibers were anchored on the surface of the poly(ethylene terephthalate) fibers by heat treatment to form a crosslinked nanostructured mesh with very high porosity and high specific surface area. The pore size and distribution of the membranes can be adjusted by varying the loading amount of nanofibers. The resulting membrane not only possessed good interception ability for 5, 3, and 1.3 µm polystyrene microspheres but also exhibited desirable water permeability. In the circulating filtration test, with the accumulation of membrane fouling in the filtration, the membrane was also effective in retaining particulate matter while improving the antipollution ability. These properties are desirable for the effective removal of pollutants on the membrane and restoration of the membrane flux.

Investigation of Supermolecular Structure of Fluorine-Containing Polyethyleneterephthalate Monofibers

The effect of a new modifier based on a polyfluorinated alcohol immobilized on montmorillonite nanoclay on the supermolecular structure of polyethyleneterephthalate was studied by Fourier IR spectroscopy, x-ray structural analysis, DSC, DMA, and atomic-force microscopy (AFM). It was established that the effect of the fluorine-containing modifier, involving reorganization of the molecular and crystal structure of the polymer, is complex in nature, leading to an increase of the degree of crystallinity and raising the level of surface uniformity in the obtained polyester nanofibers.

Aliphatic Polyester Nanofibers Functionalized with Cyclodextrins and Cyclodextrin-Guest Inclusion Complexes.

The fabrication of nanofibers by electrospinning has gained popularity in the past two decades; however, only in this decade, have polymeric nanofibers been functionalized using cyclodextrins (CDs) or their inclusion complexes (ICs). By combining electrospinning of polymers with free CDs, nanofibers can be fabricated that are capable of capturing small molecules, such as wound odors or environmental toxins in water and air. Likewise, combining polymers with cyclodextrin-inclusion complexes (CD-ICs), has shown promise in enhancing or controlling the delivery of small molecule guests, by minor tweaking in the technique utilized in fabricating these nanofibers, for example, by forming core–shell or multilayered structures and conventional electrospinning, for controlled and rapid delivery, respectively. In addition to small molecule delivery, the thermomechanical properties of the polymers can be significantly improved, as our group has shown recently, by adding non-stoichiometric inclusion complexes to the polymeric nanofibers. We recently reported and thoroughly characterized the fabrication of polypseudorotaxane (PpR) nanofibers without a polymeric carrier. These PpR nanofibers show unusual rheological and thermomechanical properties, even when the coverage of those polymer chains is relatively sparse (~3%). A key advantage of these PpR nanofibers is the presence of relatively stable hydroxyl groups on the outer surface of the nanofibers, which can subsequently be taken advantage of for bioconjugation, making them suitable for biomedical applications. Although the number of studies in this area is limited, initial results suggest significant potential for bone tissue engineering, and with additional bioconjugation in other areas of tissue engineering. In addition, the behaviors and uses of aliphatic polyester nanofibers functionalized with CDs and CD-ICs are briefly described and summarized. Based on these observations, we attempt to draw conclusions for each of these combinations, and the relationships that exist between their presence and the functional behaviors of their nanofibers.

Alternating copolymerization of epoxides with carbon dioxide or cyclic anhydrides using bimetallic nickel and cobalt catalysts: Preparation of hydrophilic nanofibers from functionalized polyesters

A series of di-nuclear metal acetate complexes 1–6 incorporated by nitrogen heterocycle-containing salen-type ligands have been synthesized, structurally characterized and performed as catalysts to prepare biodegradable polycarbonates and polyesters. Their catalytic performances for copolymerization of carbon dioxide-epoxides or cyclic anhydride-epoxides were systematically examined. Bimetallic nickel(II) complexes 1, 2 and 5 were active catalysts for the alternating copolymerization of cyclohexene oxide (CHO) with CO2; di-nickel complex 1 was shown to be the most effective and selective, leading to obtaining poly(cyclohexene carbonate)s with the best efficiency among them. Moreover, complex 1 was also found to be versatile for the ring-opening copolymerization of CO2 with different cyclic epoxides to give the corresponding polycarbonates. Additionally, di-cobalt(II) analogs 3, 4 and 6 were efficient catalysts for the alternating copolymerization of CHO and phthalic anhydride (PA) under mild conditions. Based on the results of catalytic studies, complex 3 was demonstrated to be the most active one CHO-PA copolymerization, producing the polymeric products with a “controlled” manner involving controllable molecular weights and narrow polydispersity. Interestingly, Co complex 3 was also able to catalyze the copolymerization of PA with 4-vinyl-1,2-cyclohexene oxide to obtain the associated polyester with the vinyl functionality on the side chains, which was further functionalized with tertiary amine moieties via thiol-ene click functionalization and converted to nanofibers through electrospinning. Due to the incorporation of polar groups, the resulting tertiary amine-modified polyester nanofibers that exhibit an improved hydrophilic property relative to their un-modified counterpart have been considered to have high potential to be utilized as a new functional fiber material.

Fabrication of Two Polyester Nanofiber Types Containing the Biobased Monomer Isosorbide: Poly (Ethylene Glycol 1,4-Cyclohexane Dimethylene Isosorbide Terephthalate) and Poly (1,4-Cyclohexane Dimethylene Isosorbide Terephthalate).

The thermal and mechanical properties of two types of polyester nanofiber, poly (1,4-cyclohexanedimethylene isosorbide terephthalate) (PICT) copolymers and the terpolyester of isosorbide, ethylene glycol, 1,4-cyclohexane dimethanol, and terephthalic acid (PEICT), were investigated. This is the first attempt to fabricate PICT nanofiber via the electrospinning method; comparison with PEICT nanofiber could give greater understanding of eco-friendly nanofibers containing biomass monomers. The nanofibers fabricated from each polymer show similar smooth and thin-and-long morphologies. On the other hand, the polymers exhibited significantly different mechanical and thermal properties; in particular, a higher tensile strength was observed for PICT nanofiber mat than for that of PEICT. We hypothesized that PICT has more trans-configuration than PEICT, resulting in enhancement of its tensile strength, and demonstrated this by Fourier transform infrared spectroscopy. In addition, PICT nanofibers showed clear crystallization behavior upon increased temperature, while PEICT nanofibers showed completely amorphous structure. Both nanofibers have better tensile properties and thermal stability than the typical polyester polymer, implying that they can be utilized in various industrial applications.

Rationally designed particle preloading method to improve protein delivery performance of electrospun polyester nanofibers

Particle preloading method by first loading proteins onto nano- or microparticles and then integrating these particles into electrospun polyester nanofibers has been widely used to encapsulate therapeutic proteins into polyester nanofibers. However, poor method design has resulted in unsatisfactory protein delivery performance. For example, the harsh conditions involved in preloading procedures damage the bioactivities of proteins, the improper integration leads to an uneven distribution of particles in nanofibers or insecure attachment of particles to nanofibers, producing uncontrolled protein release profiles. This study aimed to improve the protein delivery performance of polyester nanofibers by rationally designing a particle preloading method. Positively charged chitosan nanoparticles (CNPs) were used as carriers to adsorb negatively charged proteins in mild conditions and as primary barriers for protein release. The polar CNPs were then homogeneously dispersed in a polar polyester solution and subjected to electrospinning. Microscope observations indicated that CNPs were homogeneously embedded within polyester nanofibers. In vitro release behaviour and cell studies showed that proteins retained their bioactivity and could release from polyester nanofibers in a sustained manner for more than 4 weeks without any initial burst. Epidermal growth factor encapsulated in polyester nanofibers enhanced diabetic wound healing in vivo, demonstrating an application potential in biomedicine. Other properties of the nanofibers, including composition, wettability, cytotoxicity, and cell adhesion and spreading, were examined in detail as well.

Electrospun polyester/cyclodextrin nanofibers for entrapment of volatile organic compounds

Polyester (PET) nanofibers incorporating cyclodextrins (CD) were obtained via electrospinning. α‐CD, β‐CD, and γ‐CD were used to functionalize PET nanofibers. Bead‐free PET/CD nanofibers were obtained from lower polymer concentration indicating that the incorporation of CD in polymer solution improved the electrospinnability of the PET nanofibers. XRD studies indicated that CD were distributed into nanofiber without forming crystalline aggregates. FTIR peak shift was observed possibly due to interaction between CD and PET. TGA confirmed that initial CD loading (25%, w/w) in the polymer solution was preserved for the PET/CD nanofibers. The presence of most of CD on the surface of PET/CD nanofibers was confirmed by XPS analysis and contact angle measurement. DMA results indicated that incorporation of CD improved the mechanical property of the nanofibers. Our studies showed that PET/CD nanofibers can effectively entrap aniline vapor as a model volatile organic compound (VOC) from surrounding owing to their very large surface area and inclusion complexation capability of CD. The entrapment efficiency of aniline vapor was found to be better for PET/γ‐CD nanofibers compared to PET/α‐CD and PET/β‐CD nanofibers. Our findings suggested that electrospun PET nanofibers functionalized with CD may be used as filtering material for removal of VOC in air filtration. POLYM. ENG. SCI., 54:2970–2978, 2014. © 2014 Society of Plastics Engineers

Surface modification of electrospun polyester nanofibers with cyclodextrin polymer for the removal of phenanthrene from aqueous solution

Surface modified electrospun polyester (PET) nanofibers with cyclodextrin polymer (CDP) were produced (PET/CDP). CDP formation onto electrospun PET nanofibers was achieved by polymerization between citric acid (CTR, crosslinking agent) and cyclodextrin (CD). Three different types of native CD (α-CD, β-CD and γ-CD) were used to form CDP. Water-insoluble crosslinked CDP coating was permanently adhered onto the PET nanofibers. SEM imaging indicated that the nanofibrous structure of PET mats was preserved after CDP surface modification process. PET/CDP nanofibers have shown rougher/irregular surface and larger fiber diameter when compared to untreated PET nanofibers. The surface analyses of PET/CDP nanofibers by XPS elucidated that CDP was present on the fiber surface. DMA analyses revealed the enhanced mechanical properties for PET/CDP where PET/CDP nanofibers have shown higher storage modulus and higher glass transition temperature compared to untreated PET nanofibers. The surface area of the PET/CDP nanofibers investigated by BET measurements showed slight decrease due to the presence of CDP coating compared to pristine PET nanofibers. Yet, it was observed that PET/CDP nanofibers were more efficient for the removal of phenanthrene as a model polycyclic aromatic hydrocarbon (PAH) from aqueous solution when compared to pristine PET nanofibers. Our findings suggested that PET/CDP nanofibers can be a very good candidate as a filter material for water purification and waste treatment owing to their very large surface area as well as inclusion complexation capability of surface associated CDP.

Multifunctional aliphatic polyester nanofibers for tissue engineering.

Electrospun fibers based on aliphatic polyesters, such as poly(ε-caprolactone) (PCL), have been widely used in regenerative medicine and drug delivery applications due to their biocompatibility, low cost and ease of fabrication. However, these aliphatic polyester fibers are hydrophobic in nature, resulting in poor wettability, and they lack functional groups for decorating the scaffold with chemical and biological cues. Current strategies employed to overcome these challenges include coating and blending the fibers with bioactive components or chemically modifying the fibers with plasma treatment and reactants. In the present study, we report on designing multifunctional electrospun nanofibers based on the inclusion complex of PCL-α-cyclodextrin (PCL-α-CD), which provides both structural support and multiple functionalities for further conjugation of bioactive components. This strategy is independent of any chemical modification of the PCL main chain, and electrospinning of PCL-α-CD is as easy as electrospinning PCL. Here, we describe synthesis of the PCL-α-CD electrospun nanofibers, elucidate composition and structure, and demonstrate the utility of functional groups on the fibers by conjugating a fluorescent small molecule and a polymeric-nanobead to the nanofibers. Furthermore, we demonstrate the application of PCL-α-CD nanofibers for promoting osteogenic differentiation of human adipose-derived stem cells (hADSCs), which induced a higher level of expression of osteogenic markers and enhanced production of extracellular matrix (ECM) proteins or molecules compared with control PCL fibers.

Development and application of high-strength polyester nanofibers

We have produced the world’s first 700 nm, ultra-fine polyester nanofiber via continuous research and development using state-of-the-art nanotechnology. The proposed sea/island composite-spinning technology has improved the quality of conventional mass-produced nanofibers. Sea/island composite spinning produces high-strength polyester nanofibers using conjugated (two components) spinning theory. The separation of sea–island components is based on the different degrees of polymer dissolution in alkali solution; specifically, resolution sea polymer (modified polyester) has dissolution rates that are 1000 times faster than that of island polymer (polyester). The resulting nanofibers have a large surface area, high absorption, and good distribution and filtration effects, which are suitable for a variety of applications, including functional sportswear, inner wear, skin-care products, filters, precision grinding cloths, and so on. The new ‘Sea/Island’ composite-spinning technology has solved the problem of unstable quality associated with conventional mass-production nanofibers. ‘Sea/island’ composite spinning achieves the high-strength polyester nanofiber based on conjugated (two components) spinning theory. The separation process between sea–islands components is successful with 1000 times faster in alkali solution resolution sea polymer than island polymer. Nanofiber has a very large surface area, absorption, distribution and filtration effect, which are suitable for a variety of applications, including functional sportswear, inner wear, skin-care products, filters, precision grinding cloth, and so on.

Water-Stable All-Biodegradable Microparticles in Nanofibers by Electrospinning of Aqueous Dispersions for Biotechnical Plant Protection

Pheromone eluting oligolactide (OLA) microcapsules immobilized in electrospun biodegradable polyester nanofibers were obtained by electrospinning of aqueous dispersions of the microcapsules. OLA was prepared by conventional melt polycondensation of lactic acid. Following the protocol of the solvent displacement method, OLA was dissolved in acetone and mixed with Brij S20 and the pheromone of the European grape vine moth, Lobesia Botrana, (E,Z)-7,9-dodecadien-l-yl acetate (DA). Up to 32 wt % of this mixture could be dispersed in water with colloidal stability of several weeks without any sedimentation. Without DA as well as OLA, no stable dispersions of OLA in water were obtained. Replacement of DA by classical hydrophobes typically used for miniemulsions did not yield stable dispersions, but the addition of octyl acetate, which shows structural similarity to DA, yielded stable dispersions in water up to 10 wt %. Dispersions of OLA/DA were successfully electrospun in combination with an aqueous dispersion of a biodegradable block copolyester resulting in water-stable nanofibers containing OLA/DA microcapsules. Release of DA from microcapsules and fibers was retarded in comparison with non-encapsulated DA, as shown by model studies.

Preparation of polyester nanofibers and nanofiber yarns from polyester/cellulose acetate butyrate immiscible polymer blends

AbstractDevelopment of high throughput production processes for making thermoplastic nanofiber and nanofiber yarns are urgently needed. PET, PTT, and PBT nanofibers were prepared from PET/CAB, PTT/CAB, PBT/CAB immiscible polymer blends by in situ microfibrillar formation during the melt extruding process. The diameter distribution and crystallization properties of PET, PTT, and PBT nanofibers were analyzed. After removing the CAB matrix phase, the nanofibers could be collected in the forms of random or aligned nanofibers and nanofiber bundles or yarns. To understand the formation mechanism of the nanofibers, the morphology development of three different polyesters in the dispersed phase were studied with samples collected at different zones in a twin‐screw extruder. The morphological development mechanism of the dispersed phases involved the formation of sheets, holes and network structures, then the size reduction and formation of nanofibers. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Biomimetic Structures: Biological Implications of Dipeptide‐Substituted Polyphosphazene–Polyester Blend Nanofiber Matrices for Load‐Bearing Bone Regeneration

AbstractSuccessful bone regeneration benefits from three‐dimensional (3D) bioresorbable scaffolds that mimic the hierarchical architecture and mechanical characteristics of native tissue extracellular matrix (ECM). A scaffold platform that integrates unique material chemistry with nanotopography while mimicking the 3D hierarchical bone architecture and bone mechanics is reported. A biocompatible dipeptide polyphosphazene‐polyester blend is electrospun to produce fibers in the diameter range of 50–500 nm to emulate dimensions of collagen fibrils present in the natural bone ECM. Various electrospinning and process parameters are optimized to produce blend nanofibers with good uniformity, appropriate mechanical strength, and suitable porosity. Biomimetic 3D scaffolds are created by orienting blend nanofiber matrices in a concentric manner with an open central cavity to replicate bone marrow cavity, as well as the lamellar structure of bone. This biomimicry results in scaffold stress–strain curve similar to that of native bone with a compressive modulus in the mid‐range of values for human trabecular bone. Blend nanofiber matrices support adhesion and proliferation of osteoblasts and show an elevated phenotype expression compared to polyester nanofibers. Furthermore, the 3D structure encourages osteoblast infiltration and ECM secretion, bridging the gaps of scaffold concentric walls during in vitro culture. The results also highlight the importance of in situ ECM secretion by cells in maintaining scaffold mechanical properties following scaffold degradation with time. This study for the first time demonstrates the feasibility of developing a mechanically competent nanofiber matrix via a biomimetic strategy and the advantages of polyphosphazene blends in promoting osteoblast phenotype progression for bone regeneration.

Characterization of solvent‐spun polyester nanofibers

AbstractThe aim of this study was to examine the properties of polyester nanofibers produced by the electrospinning method. Solvent‐spun nanofibers with different concentrations of poly(ethylene terephthalate) (13, 16, and 20 wt %) were produced. The morphology and surface energy of the fibers were analyzed by scanning electron microscopy and contact angle measurements. Tensile testing, dynamic mechanical analysis, and differential scanning calorimetry were carried out to characterize the thermal and mechanical properties. X‐ray diffraction and attenuated total reflection Fourier transform infrared spectroscopy tests were performed to analyze the microstructural properties. The results show that a nanoweb of the 16 wt % solution had better mechanical and thermal behaviors because of the increased molecular orientation in the amorphous structure and the narrower fiber diameter distribution in the web. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011