Gopal Panthi

Fabrication of highly porous poly (ɛ-caprolactone) fibers for novel tissue scaffold via water-bath electrospinning

Highly porous fibers were prepared by water-bath electrospinning from pure poly(ɛ-caprolactone) (PCL), and its blends with methoxy poly(ethylene glycol) (MPEG). These fibers were further analyzed by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), X-ray diffraction (XRD), and gravimetric as well as contact angle measurement. SEM images showed that the fibers diameters as well as pores diameter on the fibers were affected by the weight ratio of MPEG/PCL. DSC and XRD not only revealed suppression of crystallinity of PCL but also indicated the presence of trace amount of MPEG in PCL water-bath collected fibers. The potential use of these hydrophilic porous electrospun fibrous mats as scaffolding materials was evaluated in vitro using mouse osteoblasts (MC3T3-E1) as reference cell lines. Cytotoxicity assessment of the fiber mats indicated that the porous electrospun mat containing trace amount of MPEG was nontoxic to the cell. Cell culture results showed that porous fibrous mats were good in promoting the cell attachment and proliferation. This novel electrospun matrix could be used as potential tissue scaffold material.

Effect of polymer molecular weight on the fiber morphology of electrospun mats

In this work, different fractions of solvent-induced polymer degraded solution were mixed with freshly prepared solution of same polymer, and its effect on fiber morphology of electrospun mats was investigated. Nylon-6 solution in formic acid was allowed to degrade for 3 weeks and different fractions of it were mixed with freshly prepared nylon-6 solution to get the electrospun mats. FE-SEM images of the mats indicated that the a large amount of sub-nanofibers (<50 nm in diameter) in the form of spider-net like structures were achieved by tailoring the amount of solvent degraded polymer solution in the freshly prepared nylon-6 solution. Large quantity of these ultrafine sub-nanofibers present in electrospun nylon-6 mats could increase its hydrophilicity and mechanical strength. The decreased average pore diameter and increased BET surface area of the mat, caused by spider-net like structure, can make it as a potential candidate for air/water filtration.

Novel preparation and characterization of human hair-based nanofibers using electrospinning process

Human hair-based biocomposite nanofibers (NFs) have been fabricated by an electrospinning technique. Aqueous keratin extracted from human hair was successfully blended with poly(vinyl alcohol) (PVA). The focus here is on transforming into keratin/PVA nanofibrous membranes and insoluble property of electrospun NFs. The resulting hair-based NFs were characterized using Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), differential scanning colorimetry (DSC), and thermogravimetric analysis (TGA). Toward the potential use of these NFs after cross-linking with various weight fractions of glyoxal, its physicochemical properties, such as morphology, mechanical strength, crystallinity, and chemical structure were investigated. Keratin/PVA ratio of 2/1 NFs with 6 wt%-glyoxal showed good uniformity in fiber morphology and suitable mechanical properties, and excellent antibacterial activity providing a potential application of hair-based NFs in biomedical field.

Preparation and characterization of nylon-6/gelatin composite nanofibers via electrospinning for biomedical applications

Easy fabrication, porosity, good mechanical properties, and composition controllable of the electrospun nanofiber mat make this material a promising candidate for wound dressing applications. In the present study, nylon6/gelatin electrospun nanofiber mats are introduced as novel wound dressing materials. The introduced mats were synthesized by electrospinning of nylon6 and gelatin mixtures, three mats containing different gelatin content were prepared; 10, 20 and 30 wt%. Interestingly, addition of the gelatin did not affect the mechanical properties of the nylon 6, moreover the mat containing 10 wt% gelatin revealed higher mechanical properties due to formation of spider-net like structure from very thin nanofibers (∼10 nm diameter) bonding the main nanofibers. Biologically study indicates that gelatin incorporation strongly enhances the bioactivity performance as increasing the gelatin content linearly increases the MC3T3-E1 cell attachment. Overall, the obtained results recommend exploiting the introduced mats as wound dressing material.

PAN electrospun nanofibers reinforced with Ag2CO3 nanoparticles: Highly efficient visible light photocatalyst for photodegradation of organic contaminants in waste water

This paper presents fabrication of polyacrylonitrile (PAN) electrospun nanofibers (NFs) reinforced with Ag2CO3 nanoparticles (NPs) as highly efficient visible light photocatalyst. Preparation of the introduced NFs was accomplished by using simple, effective, high yield, and low cost process; electrospinning of Ag2CO3/PAN colloidal solution at different applied electric voltages. Photocatalytic efficiency of the introduced nanofiber mats was investigated by photodegradation of three dyes (Methyl orange, Methylene blue, and RhodamineB) under visible light irradiation. Experimental results indicated that the nanofiber mat obtained at applied electric voltage of 18 kV could show higher performance towards the photodegradation of organic contaminants. Moreover, field emission scanning electron microscopy (FE-SEM) and transmission electron microscope (TEM) analysis confirmed the confinement of Ag2CO3 NPs inside polymeric NFs, which can overcome the serious problems of photocorrosion of photocatalyst and secondary pollution. Overall, the introduced NFs can be used as efficient, low cost, and healthily safe visible light driven photocatalyst in the field of water treatment and can promote its industrial application, especially in the open water surfaces.

Synthesis and characterization of photocatalytic and antibacterial PAN/Ag2CO3 composite nanofibers by ion exchange method

Highly photocatalytic and antibacterial Ag2CO3 nanoparticles were incorporated into PAN nanofibers by electrospinning technique followed by ion exchange reaction between silver nitrate and sodium bicarbonate at room temperature. The samples were characterized by field-emission scanning electron microscopy (FE-SEM), Transmission electron microscopy (TEM), X-ray diffraction (XRD), photoluminescence (PL), and Fourier transformed infrared (FT-IR) spectroscopy. The as prepared sample was found to exhibit an excellent photocatalytic activity toward degradation of methylene blue (MB) in aqueous solution and antibacterial properties against Escherichia coli (E. coli) under visible light. The perfect recovery of catalyst after reaction and its unchanged efficiency for cyclic use showed that it will be an economically and environmentally friendly photocatalyst for the water purification.