scholarly journals Characterization, Biocompatibility, and Optimization of Electrospun SF/PCL/CS Composite Nanofibers

Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1439
Author(s):  
Hua-Wei Chen ◽  
Min-Feng Lin

In this study, composite nanofibers (SF/PCL/CS) for the application of dressings were prepared with silk fibroin (SF), polycaprolactone (PCL), and chitosan (CS) by electrospinning techniques, and the effect of the fiber diameter was investigated using the three-stage Taguchi experimental design method (L9). Nanofibrous scaffolds were characterized by the combined techniques of scanning electron microscopy (SEM) and transmission electron microscopy (TEM), a cytotoxicity test, proliferation tests, the antimicrobial activity, and the equilibrium water content. A signal-to-noise ratio (S/N) analysis indicated that the contribution followed the order of SF to PCL > flow rate > applied voltage > CS addition, possibly owing to the viscosity and formation of the beaded fiber. The optimum combination for obtaining the smallest fiber diameter (170 nm) with a smooth and uniform distribution was determined to be a ratio of SF to PCL of 1:2, a flow rate of 0.3 mL/hr, and an applied voltage of 25 kV at a needle tip-to-collector distance of 15 cm (position). The viability of these mouse fibroblast L929 cell cultures exceeded 50% within 24 hours, therefore SF/PCL/CS could be considered non-toxic according to the standards. The results proposed that the hydrophilic structure of SF/PCL/CS not only revealed a highly interconnected porous construction but also that it could help cells promote the exchange of nutrients and oxygen. The SF/PCL/CS scaffold showed a high interconnectivity between pores and porosity and water uptake abilities able to provide good conditions for cell infiltration and proliferation. The results from this study suggested that SF/PCL/CS could be suitable for skin tissue engineering.

2013 ◽  
Vol 845 ◽  
pp. 985-988 ◽  
Author(s):  
N.H.A. Ngadiman ◽  
M.Y. Noordin ◽  
Ani Idris ◽  
Denni Kurniawan

Fabrication of nanofibers using electrospinning has recently attracted much attention for various applications due to its simplicity. Electrospinning has the ability to produce nanofibers within 100-500 nm. Some applications require certain fiber diameter. As a relatively new process, there are many electrospinning parameters that are believed to influence the nanofibers diameter. The purpose of this review is to identify and discuss the effect of some of those parameters, i.e. concentration, spinning distance, and applied voltage, and volume flow rate, to the nanofiber diameter during electrospinning process. It was concluded that fiber volume flow rate is proportional to fiber diameter while there is no agreement in reports on other parameters.


2019 ◽  
Vol 290 ◽  
pp. 286-291
Author(s):  
Nur Mariam Kamaruddin ◽  
Shahrom Mahmud ◽  
Sufiniza Nordin ◽  
Abdulsalam Abuelsamen ◽  
Azman Seeni ◽  
...  

Apart from being a promising optoelectronic devices such as photodetector and sensors, ZnO has many dental and biomedical applications. ZnO has been known to possess strong toxicity towards bacteria, cancer and fungi. Cytotoxicity test of pharmaceutical grade of ZnO on L929 mouse fibroblast cell lines was carried out using trypan blue assay. ZnO was characterized for its morphology, structure and optical properties using FESEM, EDS, UV-Vis and XRD. ZnO exhibited various morphologies like rod, platelet, slab and irregular-shaped particles. EDS data showed the ZnO powder possessed relatively higher oxygen atomic percentage if compared to zinc atoms with an oxygen-to-zinc ratio of 1.219. The average crystallite size obtained was about 39 nm. The percentage of cell viability on L929 cell was decreased with increasing ZnO concentrations. The cells viability after 72h were achieved and the concentration of ZnO below 1 mM was summarized as non-toxic after treated with ZnO. The higher surficial oxygen on ZnO particle surface could have promoted higher generation of reactive oxygen species that caused lower L929 cell viability.


2020 ◽  
Vol 859 ◽  
pp. 239-243
Author(s):  
Nawinda Chinatangkul ◽  
Sirikarn Pengon ◽  
Suchada Piriyaprasarth ◽  
Chutima Limmatvapirat ◽  
Sontaya Limmatvapirat

The aim of this study was to develop the electrospun shellac (SHL) and hydroxypropyl cellulose (HPC) blended nanofibers for drug carrier application. The effects of polymer solution and electrospinning parameters, including SHL-HPC ratio, HPC concentration, applied voltage and flow rate, on the appearance of fibers were investigated. Based on the results, electrospun fiber was not obtained when a solution of HPC alone was employed. However, the fibers would be obviously fabricated as SHL was added to the HPC solution. An increase in the SHL ratio in SHL-HPC blended solution could accordingly lead to a remarkable enhance in the fiber diameter. In addition, the continuous nanofibers with less beads were gradually formulated when the HPC concentration was increased. The electrospinning parameters seemed to be significant. The elevation of infusion rate from 0.5 to 1 mL/h would contribute to the preparation of thick fibers with the diameters enlarging from 666.9 to 843.5 nm. With the applied voltage increasing from 15 to 30 kV during the electrospinning process, the fabrication of small nanofibers with the diameters reducing from 843.5 to 741.6 nm would be conducted. In this study, monolaurin (ML), a broad antimicrobial agent, was encapsulated into the SHL-HPC carrier for the purpose of drug delivery application. Regarding the result, the loaded concentration of ML could not be enhanced by introducing HPC to the SHL fibers.


Author(s):  
Yuanyuan Duan ◽  
Lohitha Kalluri ◽  
Megha Satpathy ◽  
Yuanyuan Duan

Background: Poly lactic-co-glycolic acid (PLGA) has been widely investigated for various biomedical applications, such as craniofacial bone regeneration, wound dressing and tissue engineering. Electrospinning is a versatile technology used to produce micro/nanoscale fibers with large specific surface area and high porosity. Purpose: The aim of the current study is to prepare PLGA nanofibers using electrospinning for guided tissue regeneration/guided bone regeneration applications. The objective of this study is to determine the appropriate electrospinning parameters such as applied voltage, flow rate, spinneret-collector distance and polymer solution concentration for preparation of PLGA fibrous membrane and their effect on the mean fiber diameter of the electrospun fibers. Method: PLGA pellets were dissolved in Hexafluoroisopropanol (HFIP) in various concentrations overnight using a bench rocker. The resulting PLGA solution was then loaded into a syringe and electrospinning was done by maintaining the other parameters constant. Similarly, various fibrous mats were collected by altering the specific electrospinning parameter inputs such as applied voltage, flow rate and spinneret-collector distance. The morphology of the fibrous mats was characterized using Scanning Electron Microscope. The mean fiber diameter was assessed using ImageJ software and the results were compared using one-way ANOVA. Results: We obtained bead-free uniform fibers with various tested solution concentrations. One-way ANOVA analysis demonstrated significant variation in mean fiber diameter of the electrospun fibers with altering applied voltage, solution concentration, flow rate and spinneret-collector distance. Conclusion: The above-mentioned electrospinning parameters and solution concentration influence the mean fiber diameter of electrospun PLGA nanofibers.


2018 ◽  
Vol 55 (1B) ◽  
pp. 216 ◽  
Author(s):  
Viet Linh Nguyen - Vu

In this study, electrospray modes were investigated to clarify their effects on the morphology and size of polycaprolactone (PCL) particles. The result indicated that electrosprayed microspheres with homogeneous and stable morphology were fabricated by using cone–jet mode and suitable electrospray processing parameters. Besides, the PCL solution was created by dissolving in dichloromethane with different concentrations such as 3.5%, 4%, 4.5% and 5%. The scanning electron microscopy (SEM) micrographs pointed that electrosprayed PCL microspheres were formed by using 4.5 % polymer solution. In addition, the reproducible and homogeneous morphology of PCL microparticles were obtained at the following set of parameters: applied voltage of 18 kV, flow rate of 1.5 mL/h and distance tip to collector of 20 cm. Moreover, at the collecting distance of 15–25 cm, the flow rate of 1.2–1.8 mL/h and applied voltage of 18 kV the cone–jet mode was generated. It was an effective electrospray mode to create stable and homogeneous microspheres.


2009 ◽  
Vol 87-88 ◽  
pp. 555-560
Author(s):  
Wei Min Kang ◽  
Bo Wen Cheng ◽  
Quan Xiang Li ◽  
Xu Pin Zhuang

A kind of novel biodegradable poly(hexamethylene adipate) (PHMA) nanofibers with diameter of 100~700nm using a mixed solvent of 1,2-dichloroethane (DCE ) and trifluoroacetic acid (TFA) were obtained by electrospinning process in this paper. The morphology of electropun PHMA nanofibers were investigated by scanning electron microscopy (SEM). The results showed that the morphology, diameter and uniformity of the fibers were influenced by solvent ratio, solution concentration, applied voltage, capillary–screen distance and flow rate greatly. The finer and uniform nanofibers were electrospun from a mixed solvent of DCE and TFA with ratio of 70/30(w/w).


2021 ◽  
Vol 21 (12) ◽  
pp. 5912-5919
Author(s):  
Zhi-Yuan Feng ◽  
Chen-Di Wang ◽  
Soo-Jin Park ◽  
Wan Meng ◽  
Long-Yue Meng

Chitosan (CS), the only alkaline polysaccharose available in nature, has always been a promising candidate for drug delivery owing to its excellent biodegradability and biocompatibility. However, inherent solubility and polycationic properties of CS largely hinder electrospinning, which is an efficient method of fabricating nanofibers for drug carriers. To solve this problem and extend the applications of CS, polyamide/chitosan/tetraethyl orthosilicate (PA/CS/TEOS) composite nanofibers were successfully prepared as drug carriers in this study via electrospinning. The PA/CS/TEOS ratios significantly influenced the nanofiber morphology. As the content of each was increased, the beads among the membranes increased initially and then decreased, determined by scanning electron microscopy (SEM). The morphology of the optimum membranes with the ratio of 1:0.13:0.67 was smoother with less beads and uniform fiber diameter. Finally, the membranes with optimum ratios were used as carriers of ofloxacin in the study of drug release performance to identify their future feasibility, which revealed an initial fast release followed by a relatively stable release.


2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Dikeledi S. More ◽  
Makwena J. Moloto ◽  
Nosipho Moloto ◽  
Kgabo P. Matabola

In this study, chitosan (CS)/poly(vinyl alcohol) (PVA) (CS/PVA) blend nanofibers with varying weight ratios and silver (Ag)/copper (Cu)/CS/PVA composite fibers have been prepared successfully by the electrospinning process. The tip-to-collector distance was kept at 15 cm, and the applied voltage was varied from 15 to 25 kV. The effects of the weight ratios and applied voltage on the morphology and diameter of the fibers were investigated. The resultant fibers were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). The SEM results showed that increasing the amount of chitosan in the CS/PVA blend resulted in a decrease in the fiber diameter from 162 to 89 nm while an increase in the voltage from 15 to 25 kV led to a decrease in the fiber diameters. Furthermore, the SEM results indicated that an increase in the fiber diameter from 161 to 257 nm was observed while morphological changes were also observed upon the Ag/Cu addition. The latter changes are perceived to be a result of increased conductivity and higher charge density.


2020 ◽  
Vol 846 ◽  
pp. 14-22
Author(s):  
Gianina Martha A. Tajanlangit ◽  
Leslie Joy L. Diaz

Iron-modified montmorillonite-filled polycaprolactone nanofiber mats were produced via electrospinning with varying applied voltage, flow rate, needle-tip-to-collector distance, and needle diameter. Scanning electron microscopy (SEM) was used to observe fiber morphology and characteristics. The effects of varying process parameters on various fiber characteristics were evaluated using a two-level fractional factorial experimental design. The effect of voltage on fiber diameter differed with varying flow rate. At 32 ml/hr, the average fiber diameter decreased from 518.38 nm ± 289.37 nm to 466.43 nm ± 312.36 nm when the voltage is increased. At 42 ml/hr the effect of voltage on fiber diameter was reversed. The average fiber diameter was also found to decrease from 516.03 nm ± 283.48 nm to 467.96 nm ± 318.07 nm with decreasing tip-to-collector distance at 32 mL/hr flow rate. The variation of the effect of the factors on fiber diameter was mainly due to a significant loss of material observed at 12 kV and 15 cm tip-to-collector distance. Bead formation was observed for all runs with more beads being formed at 12 kV applied voltage and 15 cm tip-to-collector distance. Spherical beads were observed at 12 kV and 15 cm tip-to-collector distance while spindle-like beads were present in nanofiber membranes spun at high voltage and at the combination of low voltage and low tip-to-collector distance. The parameter setting combination of 19 kV, 32 ml/hr flow rate, 10 cm tip-to-collector distance, and 0.514 mm needle diameter yielded the lowest fiber diameter with the least amount of beading and small bead size. Small fiber diameters and less beading provide larger surface area and more exposure of the Fe-MMT particles for more efficient adsorption.


Author(s):  
Joe A. Mascorro ◽  
Gerald S. Kirby

Embedding media based upon an epoxy resin of choice and the acid anhydrides dodecenyl succinic anhydride (DDSA), nadic methyl anhydride (NMA), and catalyzed by the tertiary amine 2,4,6-Tri(dimethylaminomethyl) phenol (DMP-30) are widely used in biological electron microscopy. These media possess a viscosity character that can impair tissue infiltration, particularly if original Epon 812 is utilized as the base resin. Other resins that are considerably less viscous than Epon 812 now are available as replacements. Likewise, nonenyl succinic anhydride (NSA) and dimethylaminoethanol (DMAE) are more fluid than their counterparts DDSA and DMP- 30 commonly used in earlier formulations. This work utilizes novel epoxy and anhydride combinations in order to produce embedding media with desirable flow rate and viscosity parameters that, in turn, would allow the medium to optimally infiltrate tissues. Specifically, embeding media based on EmBed 812 or LX 112 with NSA (in place of DDSA) and DMAE (replacing DMP-30), with NMA remaining constant, are formulated and offered as alternatives for routine biological work.Individual epoxy resins (Table I) or complete embedding media (Tables II-III) were tested for flow rate and viscosity. The novel media were further examined for their ability to infilftrate tissues, polymerize, sectioning and staining character, as well as strength and stability to the electron beam and column vacuum. For physical comparisons, a volume (9 ml) of either resin or media was aspirated into a capillary viscocimeter oriented vertically. The material was then allowed to flow out freely under the influence of gravity and the flow time necessary for the volume to exit was recored (Col B,C; Tables). In addition, the volume flow rate (ml flowing/second; Col D, Tables) was measured. Viscosity (n) could then be determined by using the Hagen-Poiseville relation for laminar flow, n = c.p/Q, where c = a geometric constant from an instrument calibration with water, p = mass density, and Q = volume flow rate. Mass weight and density of the materials were determined as well (Col F,G; Tables). Infiltration schedules utilized were short (1/2 hr 1:1, 3 hrs full resin), intermediate (1/2 hr 1:1, 6 hrs full resin) , or long (1/2 hr 1:1, 6 hrs full resin) in total time. Polymerization schedules ranging from 15 hrs (overnight) through 24, 36, or 48 hrs were tested. Sections demonstrating gold interference colors were collected on unsupported 200- 300 mesh grids and stained sequentially with uranyl acetate and lead citrate.


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