Prepared Electrospun Nanofibers Research Articles

A novel sorbent based on electrospun for electrically-assisted solid phase microextraction of six non-steroid anti-inflammatory drugs, followed by quantitation with HPLC-UV in human plasma samples

BackgroundAlthough NSAIDs possess notable therapeutic and pharmaceutical qualities, it's essential to acknowledge that excessive doses can result in toxicity within the human body. Moreover, the importance lies in identifying and measuring their trace amounts. Due to their existence within intricate matrices, the creation of novel electrospun nanofibers as sorbents for electrically-assisted solidphase microextraction (EA-SPME) becomes vital. This innovation caters to the requirement for the effective pre-treatment of NSAID samples, providing a strategic approach to managing the complexities associated with trace quantities found in various matrices. ResultsFirst, polyvinylalcohol/casein/tannic acid/polyaniline/titanium dioxide nanoparticles (PVA/CAS/TA/PANI/TiO2 NPs) electrospun nanofibers were prepared for EA-SPME on pewter rode and then, trace amounts of six NSAIDs (Acetaminophen, Caffeine, Naproxen, Celecoxib, Ibuprofen and mefenamic acid) were adsorbed chemically on these nanofibers. In the next step, the desorption of six NSAIDs was electrochemically done from prepared electrospun nanofibers on a pewter rod which was as working electrode at three electrodes system. Finally, these drugs were quantified from different human plasma samples with HPLC-UV. The synthesis of electrospun nanofibers was confirmed through a series of analytical techniques including field emission-scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy with elemental mapping analysis (EDX-Mapping), X-ray diffraction (XRD), and Fourier transform-infrared (FT-IR). The optimal percentage of additive compounds to PVA/CAS for electrospinning, as well as the factors influencing adsorption and desorption processes, were determined through both of Design Expert software and MATLAB programming language. SignificanceUnder optimum conditions, the wide linear range was 27–8000 ng mL−1 with R2≥ 0.9897, low detection limits were ranged from 8 to 27.3 ng mL−1 based on S/N = 3 and significant enrichment factors were acquired. The intra-day and inter-day RSDs% were obtained within the 4.51% - 5.68% and 4.28%–5.45%, respectively. Finally, The effectiveness of the EA-SPME-HPLC-UV method was assessed for determining NSAIDs in plasma samples, demonstrating good recoveries ranging from 90.2% to 105.2%.

Improving Solubility and Permeability of Hesperidin through Electrospun Orange-Peel-Extract-Loaded Nanofibers.

Orange peel, which is a rich source of polyphenolic compounds, including hesperidin, is produced as waste in production. Therefore, optimization of the extraction of hesperidin was performed to obtain its highest content. The influence of process parameters such as the kind of extraction mixture, its temperature and the number of repetitions of the cycles on hesperidin content, the total content of phenolic compounds and antioxidant (DPPH scavenging assay) as well as anti-inflammation activities (inhibition of hyaluronidase activity) was checked. Methanol and temperature were key parameters determining the efficiency of extraction in terms of the possibility of extracting compounds with the highest biological activity. The optimal parameters of the orange peel extraction process were 70% of methanol in the extraction mixture, a temperature of 70 °C and 4 cycles per 20 min. The second part of the work focuses on developing electrospinning technology to synthesize nanofibers of polyvinylpyrrolidone (PVP) and hydroxypropyl-β-cyclodextrin (HPβCD) loaded with hesperidin-rich orange peel extract. This is a response to the circumvention of restrictions in the use of hesperidin due to its poor bioavailability resulting from low solubility and permeability. Dissolution studies showed improved hesperidin solubility (over eight-fold), while the PAMPA-GIT assay confirmed significantly better transmucosal penetration (over nine-fold). A DPPH scavenging assay of antioxidant activity as well as inhibition of hyaluronidase to express anti-inflammation activity was established for hesperidin in prepared electrospun nanofibers, especially those based on HPβCD and PVP. Thus, hesperidin-rich orange peel nanofibers may have potential buccal applications to induce improved systemic effects with pro-health biological activity.

Organic solvent-free starch-based green electrospun nanofiber mats for curcumin encapsulation and delivery

Developing green and efficient methods for the delivery of active food substances is a sustained demand for food scientists and industries. In this work, for the first time, we prepared a curcumin (CUR)-loaded starch-based fast-dissolving nanofiber by electrospinning technology. This green nanofiber was obtained by incorporating CUR with octenyl succinic anhydride starch (OSA) and pullulan (PUL) matrix using pure water as the solvent. To overcome the poor water-solubility and bioavailability of CUR, hydroxypropyl-beta-cyclodextrin (HPβCD) was used to form inclusion complexes. Phase solubility test results showed that by introducing HPβCD, the water-solubility of CUR was obviously improved. The prepared electrospun nanofibers were systematically characterized through scanning electron microscopy (SEM), X-ray diffraction (XRD), proton nuclear magnetic resonance spectroscopy (1H NMR), Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), encapsulation efficiency testing, solubility testing and antioxidant activity testing. The results demonstrated that CUR was well encapsulated into HPβCD and OSA/PUL/CUR-HPβCD electrospun nanofibers with fine morphology and fast-dissolving character were successfully prepared. It is worth noting that the whole process and raw materials were green, suggesting that the prepared fast-dissolving nanofiber has great application potential in the food and pharmaceutical fields.

Bioactive Silvadur loaded polyacrylonitrile nanofibrous membranes for wound dressing applications

Persistent wounds are the most problematic for the patient as well as for the health system. Skin wounds are most exposed to bacterial attacks, which not only cause wound infections but also slow down the healing process. There is a dire need to develop a better wound dressing or scaffold material that can increase the wound healing process. This study involves the development of electrospun nanofibers based on Silvadur-loaded polyacrylonitrile membranes. Samples were developed by using five different concentrations (2 wt%, 4 wt%, 6 wt%, 8 wt%, and 10 wt%) of Silvadur loaded in PAN solution. Resultant nanofibers were characterized by SEM, FTIR, XRD, and antibacterial tests. SEM analysis confirms that all the prepared electrospun nanofibrous membranes have smooth and beads-free surfaces. The average diameter of developed nanofibers lies in the range of 150 nm to 190 nm. It was confirmed that as the concentration of Silvadur increased the diameter of nanofibers also increased due to the increase in the viscosity of the electrospinning solution. FTIR interpretation confirms that the interaction between the PAN and Silvadur is physical, not chemical. XRD analysis reflects the crystallographic and macromolecular structure of prepared electrospun nanofibers. A qualitative antibacterial test was performed to check the antibacterial properties of prepared electrospun nanofibers against gram-negative bacteria (Escherichia Coli) and gram-positive bacteria (Staphylococcus Aureus). The result reveals that nanofibers loaded with the maximum concentration of Silvadur show the maximum antibacterial activity of 92.25% against Escherichia Coli and 98.52% against Staphylococcus Aureus. The higher antibacterial activity against gram-negative bacteria is due to the thinner cell wall as compared to the gram-positive bacteria.

Antibacterial and wound healing properties of cellulose acetate electrospun nanofibers loaded with bioactive glass nanoparticles; in-vivo study

AbstractBioactive glasses (BGs) have gained great attention owing to their versatile biological properties. Combining BG nanoparticles (BGNPs) with polymeric nanofibers produced nanocomposites of great performance in various biomedical applications especially in regenerative medicine. In this study, a novel nanocomposite nanofibrous system was developed and optimized from cellulose acetate (CA) electrospun nanofibers containing different concentrations of BGNPs. Morphology, IR and elemental analysis of the prepared electrospun nanofibers were determined using SEM, FT-IR and EDX respectively. Electrical conductivity and viscosity were also studied. Antibacterial properties were then investigated using agar well diffusion method. Moreover, biological wound healing capabilities for the prepared nanofiber dressing were assessed using in-vivo diabetic rat model with induced wounds. The fully characterized CA electrospun uniform nanofiber (100–200 nm) with incorporated BGNPs exhibited broad range of antimicrobial activity against gram negative and positive bacteria. The BGNP loaded CA nanofiber accelerated wound closure efficiently by the 10th day. The remaining wound areas for treated rats were 95.7 ± 1.8, 36.4 ± 3.2, 6.3 ± 1.5 and 0.8 ± 0.9 on 1st, 5th, 10th and 15th days respectively. Therefore, the newly prepared BGNP CA nanocomposite nanofiber could be used as a promising antibacterial and wound healing dressing for rapid and efficient recovery.

Controlled Release of Chlorogenic Acid from Polyvinyl Alcohol/Poly(γ-Glutamic Acid) Blended Electrospun Nanofiber Mats with Potential Applications in Diabetic Foot Treatment.

This work biosynthesized poly(γ-glutamic acid) (γ-PGA) produced by Bacillus licheniformis ATCC-9945a. This material was utilized to prepare electrospun nanofibers with solutions of 10% polyvinyl alcohol (PVA) (w/v) mixed with γ-PGA at 5 and 10% w/v, intended as a wound dressing for diabetic foot treatment. These solutions were loaded with chlorogenic acid (CGA), an active hypoglycemic agent. Morphological analysis showed a decrease in size of the fibers with the combination of PVA/γ-PGA compared to pure PVA nanofibers, which was attributed to the hydrogen bonding interactions between the glutaraldehyde vapors, γ-PGA, and PVA that permitted nanofiber cross-linking and allowed CGA release. The in vitro release analysis showed that the PVA membranes reached 28% delivery after the first 24 h. Notably, the nanofiber mat with PVA blended with 5% γ-PGA reached 57% delivery, and the PVA nanofiber with 10% γ-PGA reached 66% release after the same amount of time. The rate constant for the release kinetics showed that PVA with 5% γ-PGA had a higher value than that of the other samples, reaching saturation first.

Diclofenac Embedded in Silk Fibroin Fibers as a Drug Delivery System.

Silk fibroin is a biocompatible, non-toxic, mechanically robust protein, and it is commonly used and studied as a material for biomedical applications. Silk fibroin also gained particular interest as a drug carrier vehicle, and numerous silk formats have been investigated for this purpose. Herein, we have prepared electrospun nanofibers from pure silk fibroin and blended silk fibroin/casein, followed by the incorporation of an anti-inflammatory drug, diclofenac. Casein serves as an excipient in pharmaceutical products and has a positive effect on the gradual release of drugs. The characteristics of the investigated composites were estimated by scanning electron microscope, transmission electron microscope, thermogravimetric analysis, and a lifetime of diclofenac by electron paramagnetic resonance analysis. The cumulative release in vitro of diclofenac sodium salt, together with the antiproliferative effect of diclofenac sodium salt-loaded silk nanofibers against the growth of two cancer cell lines, are presented and discussed.

Poly(vinyl alcohol) triggers Au nanoparticles formation for near‐infrared radiation‐responsive gels and nanofibers

ABSTRACTThe capability of poly(vinyl alcohol) (PVA) to reduce noble metal ions and, in turn, to prepare one‐step hybrid systems that exhibit near‐infrared radiation (NIR) light‐responsiveness has been barely explored. The aim of this work was to elucidate whether gold nanoparticles (Au NPs) could be spontaneously formed in PVA gels suitable to be used as syringeable depots or to prepare electrospun nanofibers. To check the hypothesis of that the gold counterion may play a role in the Au NPs formation process, two different gold salts (HAuCl4 and AuAc3) were used. Localized surface plasmon resonance bands were monitored during the incubation of PVA‐gold salt gels, and the photoresponsive capability of the newly formed Au NPs inside gels was investigated during laser irradiation at 808 nm. HET‐CAM assay suggested good biocompatibility. Then, the feasibility of producing electrospun hybrid PVA‐based mats that exhibit light‐responsive photothermal features was explored here for the first time. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48811.

Reinforcement of electroactive characteristics in polyvinylidene fluoride electrospun nanofibers by intercalation of multi-walled carbon nanotubes

This research work reports on development and characterization of multi-walled carbon nanotube (MWCNT)-doped polyvinylidene difluoride (PVDF) nanofibers by the electrospinning method. PVDF is an extensively studied polymer both theoretically and experimentally due to its appealing ferroelectric, piezoelectric, and pyroelectric properties which strongly favors its promising applications in the development of micro/nanostructure devices. The foremost reason for its ferroelectric and piezoelectric behaviors has been attributed to its crystalline structure, specifically the presence of β-phase; however, the existence of the small percentage of β-phase in pristine PVDF limits its applications. To enhance the electroactive features in the PVDF, MWCNTs have been doped in it to prepare electrospun nanofibers, as electrospinning is a single-step approach. These nonwoven nanofibers were prepared at a DC voltage of 20 kV which were subsequently calcined at 100 °C for 12 h. The estimation of crystal structure and phase identification in these nanofibers have been determined by attenuated FT-IR and XRD, while the morphology, microstructure, mean diameter, and length have been examined by FE-SEM. The observed electrical conductivity, capacitance, permittivity (e), conductivity (δ), and impedance (Z) in these samples have been tailored by doping a range of MWCNT contents and optimizing the experimental conditions.

Indomethacin electrospun nanofibers for colonic drug delivery: In vitro dissolution studies

Generally, although the conventional drug delivery systems, such as using only pH-dependent polymers or time-dependent release systems are popular, the individuals’ variations of physiological conditions usually lead to premature or imperfect drug release from each of these systems. Therefore, a combination of pH- and time-dependent polymers could be more reliable for delivering drugs to the lower GI tract such as colon. To this end, electrospinning method was used as a fabrication approach for preparing electrospun nanofibers of indomethacin aimed for colon delivery. Formulations were prepared based on a 32 full factorial design. Independent variables were the drug:polymer ratio (with the levels of 3:5, 4.5:5 and 6:5w/w) and Eudragit S:Eudragit RS w/w ratio (20:80, 60:40 and 100:0). The evaluated responses were drug release at pH 1.2, 6.4, 6.8 and 7.4. Combinations of Eudragit S (ES), Eudragit RS (ERS) and drug based on factorial design were loaded in 10ml syringes. Electrospinning method was used to prepare electrospun nanofibers from electrospinning solutions. Conductivity and the viscosity of the solutions were analyzed prior to electrospinning. After collection, the nanofibers were evaluated in terms of morphology and drug release. It was shown that the ratio of drug:polymer and polymer:polymer were pivotal factors to control the drug release from nanofibers. A formulation containing Eudragit S:Eudragit RS (60:40) and drug:polymer ratio of 3:5 exhibited the most appropriate drug release as a colon delivery system with a minor release at pH 1.2, 6.4 and 6.8 and major release at pH 7.4. Nanofibers resulted from this formulation were also more uniform and contained fewer amounts of beads. It was demonstrated that the electrospinning could be regarded as a modern approach for the preparation of colon drug delivery systems leading to marketable products.

Preparation of biocompatible system based on electrospun CMC/PVA nanofibers as controlled release carrier of diclofenac sodium

ABSTRACTNanofibers of naturally modified polymer such as carboxymethyl cellulose (CMC) blended with poly(vinyl alcohol) (PVA) at different ratios was obtained by electrospinning technique. The blended solutions of CMC and PVA loaded with and without diclofenac sodium (DS) were electrospun using environmentally benign electrospinning technique in the absence of organic solvents. Scanning electron microscopy (SEM), Fourier transform infrared (FTIR), thermogravimetric analysis (TGA) were used to investigate the surface morphology functional groups, as well as the thermal stability of DS loaded CMC/PVA nanofibers mat. The mechanical properties of the as prepared electrospun nanofibers was also evaluated. The entrapment efficiency and the in vitro release of DS loaded CMC/PVA nanofibers were characterized using UV-Vis spectroscopy. The obtained results displayed that the blended nanofibers have shown a smooth morphology, no beads formation when the concentration of CMC was equal or below 5% and beads formation above 5%. FTIR data demonstrated that there were good interactions between CMC and PVA possibly via the formation of hydrogen bonds. The electrospun blended CMC/PVA nanofibers exhibit good mechanical properties. From the in vitro release data, it was found that with the presence of CMC, the release of DS from the nanofibers mats became sustained controlled. Due to the biocompatibility and low cost of the two blended polymers (CMC and PVA), the blended nanofibers system can be considered as one of the promising materials for the preparation of excellent drug carrier.

Preparation and evaluation of electrospun nanofibers containing pectin and time-dependent polymers aimed for colonic drug delivery of celecoxib

Objective(s):The aim of this study was to prepare electrospun nanofibers of celecoxib using combination of time-dependent polymers with pectin to achieve a colon-specific drug delivery system for celecoxib. Materials and Methods:Formulations were produced based on two multilevel 22 full factorial designs. The independent variables were the ratio of drug:time-dependent polymer (X1) and the amount of pec‌tin in formulations (X2). Electrospinning process was used for preparation of nanofibers. The spinning solutions were loaded in 5 mL syringes. The feeding rate was fixed by a syringe pump at 2.0 mL/h and a high voltage supply at range 10-18 kV was applied for electrospinning. Electrospun nanofibers were collected and evaluated by scanning electron microscopy and drug release in the acid and buffer with pH 6.8 with and without pectinase. Results:Electrospun nanofibers of celecoxib with appropriate morphological properties were produced via electrospinning process. Drug release from electrospun nanofibers was very low in the acidic media; while, drug release in the simulated colonic media was the highest from formulations containing pectin. Conclusion: Formulation F2 (containing drug:ERS with the ratio of 1:2 and 10% pectin) exhibited acceptable morphological characteristics and protection of drug in the upper GI tract and could be a good candidate as a colonic drug delivery system for celecoxib.

Stable and effective super-hydrophilic polysulfone nanofiber mats for oil/water separation

Hydrophobicity of polysulfone is the main constraint facing wide application in the most important field; water treatment, although this polymer shows promising characteristics to be used in different separation technologies. In this study, super-hydrophilic polysulfone nanofiber mats are introduced using novel modifications. The introduced nanofibers were synthesized by electrospinning of polysulfone/NaOH/DMF electrospun solution. The prepared electrospun nanofibers have been activated by deposition of a polyamide layer using interfacial polymerization (IP) reaction between m-phenylenediamine and 1,3,5-benzenetricarbonyl chloride. Three different heat treatment methodologies were investigated to enhance the characteristics of the activated nanofiber mats; normal drying at 70 °C, and soaking in boiled water followed by either normal drying at 70 °C or storing in the water. Investigation of the mechanical properties indicated that incorporation of NaOH improves the tensile stress by 40% compared to the pristine polysulfone nanofibers. Interestingly, treatment of the activated nanofiber mats in the boiled water followed by storing in water led to produce super-hydrophilic mats with water contact angle of 3° due to enhancing the IP reaction on the surface of the individual nanofibers. In oil/water separation process, the proposed heat treatment for the modified nanofiber mats resulted in increase the water flux from 8 to 12.21 m3/m2 day with oil rejection of 99.976%.

Electrospun nanofiber of hybrid manganese oxides for supercapacitor: Relevance to mixed inorganic interfaces

We prepare electrospun nanofibers (NFs) from a poly(N-vinylpyrrolidone)/manganese (II) acetate composite by electrospinning for application in supercapacitors. As-spun hybrid NFs are calcined at different temperatures to remove the polymer matrix, resulting in inorganic MnOx NFs of variable compositional ratios of Mn3O4 to Mn2O3. Interestingly, the sample of MnOx NFs that is calcined at 500 °C exhibits the highest electrochemical performance, reaching a high specific capacitance of 360.7 F g−1 at a current density of 1 A g−1. This remarkable performance is attributed to the unique three-dimensional morphology and the reduced interfacial resistance of the mixed-phase MnOx NFs within the matrix electrode and the electrolyte.

Poly(azo-ether-imide) nanocomposite films reinforced with nanofibers electrospun from multi-walled carbon nanotube filled poly(azo-ether-imide)

A high molecular weight (27 × 103 gmol−1) poly(azo-ether-imide) has been fabricated in this study. Well-aligned poly(azo-ether-imide) fibers and poly(azo-ether-imide)/multi-walled carbon nanotube nanofibers-based nanocomposite were then produced by electrospinning via self-reinforcement. Transmission electron microscopy showed that the poly(azo-ether-imide)–multi-walled carbon nanotube electrospun nanofibers were uniform and almost free of defects. Scanning electron microscopy indicated the wrapping of matrix over the bundles of nanofibrs. The as prepared electrospun nanofibers were utilized as homogeneous reinforcement to enhance the tensile strength and toughness of films. The tensile strength and tensile modulus of poly(azo-ether-imide) film reinforced with 3 wt% poly(azo-ether-imide)–multi-walled carbon nanotube nanofibers were 18% and 23% higher as compared to those of the poly(azo-ether-imide) film reinforced with 3 wt% neat poly(azo-ether-imide) nanofibers. The significant enhancement in the overall mechanical properties of the poly(azo-ether-imide)–multi-walled carbon nanotube nanofibers reinforced polyimide films was ascribed to good compatibility between the electrospun nanofibers and the matrix as well as high nanofiber orientation in the matrix. The homogeneous alignment of poly(azo-ether-imide)/multi-walled carbon nanotube nanofibers was also studied using scanning electron microscopy micrographs. Moreover, the thermal stability of poly(azo-ether-imide)/multi-walled carbon nanotube nanofibers reinforced polyimide was superior having 10% gravimetric loss at around 602–617℃ and glass transition temperature in the range of 241–263℃ relative to the neat polymer and poly(azo-ether-imide) nanofiber-based system. This study demonstrated the fabrication of high performance and high toughness polyimide nanocomposites by using this facile self-reinforcement method.

Preparation and characterization of electrospun Antheraea pernyi silk fibroin nanofibers from aqueous solution

AbstractAntheraea pernyi silk fibroin nanofibers were prepared from aqueous solution with electrospinning. The viscosity and conductivity values of the A. pernyi silk fibroin aqueous solutions with different concentrations were measured, and the morphologies of the prepared electrospun nanofibers were observed by scanning electron microscopy. The morphologies of the electrospun nanofibers changed from beadlike to uniform cylindrical and then to beltlike. The A. pernyi silk fibroin aqueous solution with a concentration of 31% exhibited good spinnability, in which uniform and regular nanofibers with an average diameter of 422 nm were obtained. The secondary structure of the electrospun A. pernyi silk fibroin nanofibers was studied by solid 13C‐NMR cross‐polarization/magic angle spinning spectroscopy, X‐ray diffraction, and differential scanning calorimetry. The as‐spun A. pernyi silk fibroin nanofibers presented a complete α‐helix/random coil structure, and no β‐sheet structure was observed. After insoluble treatment with water vapor, α‐helix and β‐sheet conformations coexisted in the A. pernyi silk fibroin nanofibers, and the β‐sheet conformation was predominant. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

A novel shortened electrospun nanofiber modified with a ‘concentrated’ polymer brush

We report the fabrication of shortened electrospun polymer fibers with a well-defined concentrated polymer brush. We first prepared electrospun nanofibers from a random copolymer of styrene and 4-vinylbenzyl 2-bromopropionate, with number-average molecular weight Mn=105 200 and weight-average molecular weight Mw=296 700 (Mw/Mn=2.82). The fibers had a diameter of 593±74 nm and contained initiating sites for surface-initiated atom transfer radical polymerization (SI-ATRP). Then, SI-ATRP of hydrophilic styrene sodium sulfonate (SSNa) was carried out in the presence of a free initiator and the hydrophobic fibers. Gel permeation chromatography confirmed that Mn and Mw/Mn values were almost the same for free polymers and graft polymers. Mn agreed well with the theoretical prediction, and Mw/Mn was relatively low (<1.3) in all the examined cases, indicating that this polymerization proceeded in a living manner. Using the values of the graft amount measured by Fourier transform infrared spectroscopy, the surface area, and Mn, we calculated the graft density σ as 0.22 chains nm−2. This value was nearly equal to the density obtained on silicon wafers (σ=0.24 chains nm−2), which is categorized into the concentrated brush regime. Finally, we mechanically cut the fibers with a concentrated poly(SSNa) brush by a homogenizer. With increasing cutting time, the fiber length became shorter and more homogenous (11±17 μm after 3 h). The shortened fibers exhibited excellent water dispersibility owing to the hydrophilic poly(SSNa) brush layer.

A novel shortened electrospun nanofiber modified with a ‘concentrated’ polymer brush

We report the fabrication of shortened electrospun polymer fibers with a well-defined concentrated polymer brush. We first prepared electrospun nanofibers from a random copolymer of styrene and 4-vinylbenzyl 2-bromopropionate, with number-average molecular weight Mn=105 200 and weight-average molecular weight Mw=296 700 (Mw/Mn=2.82). The fibers had a diameter of 593±74 nm and contained initiating sites for surface-initiated atom transfer radical polymerization (SI-ATRP). Then, SI-ATRP of hydrophilic styrene sodium sulfonate (SSNa) was carried out in the presence of a free initiator and the hydrophobic fibers. Gel permeation chromatography confirmed that Mn and Mw/Mn values were almost the same for free polymers and graft polymers. Mn agreed well with the theoretical prediction, and Mw/Mn was relatively low (<1.3) in all the examined cases, indicating that this polymerization proceeded in a living manner. Using the values of the graft amount measured by Fourier transform infrared spectroscopy, the surface area, and Mn, we calculated the graft density σ as 0.22 chains nm−2. This value was nearly equal to the density obtained on silicon wafers (σ=0.24 chains nm−2), which is categorized into the concentrated brush regime. Finally, we mechanically cut the fibers with a concentrated poly(SSNa) brush by a homogenizer. With increasing cutting time, the fiber length became shorter and more homogenous (11±17 μm after 3 h). The shortened fibers exhibited excellent water dispersibility owing to the hydrophilic poly(SSNa) brush layer.