Electrospun composite nanofibers of deoxyribonucleic acid and polylactic acid for skincare applications.

The development of useful biomaterials has resulted in significant advances in various fields of science and technology. The demand for new biomaterial designs and manufacturing techniques continues to grow, with the goal of building a sustainable society. In this study, two types of DNA-cationic surfactant complexes were synthesized using commercially available deoxyribonucleic acid from herring sperm DNA (hsDNA, <50 bp) and deoxyribonucleic acid from salmon testes DNA (stDNA, ~2000 bp). The DNA-surfactant complexes were blended with a polylactic acid (PLA) biopolymer and electrospun to obtain nanofibers, and then copper nanoparticles were synthesized on nanofibrous webs. Scanning electron microscopic images showed that all nanofibers possessed uniform morphology. Interestingly, different diameters were observed depending on the base pairs in the DNA complex. Transmission electron microscopy showed uniform growth of copper nanoparticles on the nanofibers. Fourier-transform infrared spectroscopy spectra confirmed the uniform blending of both types of DNA complexes in PLA. Both stDNA- and hsDNA-derived nanofibers showed greater biocompatibility than native PLA nanofibers. Furthermore, they exerted significant antibacterial activity in the presence of copper nanoparticles. This study demonstrates that DNA is a potentially useful material to generate electrospun nanofibrous webs for use in biomedical sciences and technologies.

Fabrication of Electrospun PVA/Zein/Gelatin Based Active Packaging for Quality Maintenance of Different Food Items.

In this research, electrospun PVA/Zein/Gelatin based tri-component active food packaging has been fabricated to enhance the shelf life of food by assuring the food quality (freshness, taste, brittleness, color, etc.) for longer. Electrospinning imparts good morphological properties along with breathability in nanofibrous mats. Electrospun active food packaging has been characterized to investigate the morphological, thermal, mechanical, chemical, antibacterial and antioxidant properties. Results of all tests indicated that the PVA/Zein/Gelatin nanofiber sheet possessed good morphology, thermal stability, mechanical strength, good antibacterial properties along with excellent antioxidant properties, which makes it the most suitable food packaging for increasing the shelf life of different food items like sweet potatoes, potatoes and kimchi. Shelf life of sweet potatoes and potatoes was observed for a period of 50 days, and shelf life of the kimchi was observed for a period of 30 days. It was concluded that nanofibrous food packaging may enhance the shelf life of fruit and vegetables because of their better breathability and antioxidant properties.

Electrospun Composite Nanofibers for Functional Applications.

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Electrospun PVA/CuONPs/Bitter Gourd Nanofibers with Improved Cytocompatibility and Antibacterial Properties: Application as Antibacterial Wound Dressing.

Antibacterial and cyto-compatible tricomponent composite electrospun nanofibers comprised of polyvinyl alcohol (PVA), copper II oxide nanoparticles (CuONPs), and Momordica charantia (bitter gourd, MC) extract were examined for their potential application as an effective wound dressing. Metallic nanoparticles have a wide range of applications in biomedical engineering because of their excellent antibacterial properties; however, metallic NPs have some toxic effects as well. The green synthesis of nanoparticles is undergoing development with the goal of avoiding toxicity. The aim of adding Momordica charantia extract was to reduce the toxic effects of copper oxide nanoparticles as well as to impart antioxidant properties to electrospun nanofibers. Weight ratios of PVA and MC extract were kept constant while the concentration of copper oxide was optimized to obtain good antibacterial properties with reduced toxicity. Samples were characterized for their morphological properties, chemical interactions, crystalline structures, elemental analyses, antibacterial activity, cell adhesion, and toxicity. All samples were found to have uniform morphology without any bead formation, while an increase in diameters was observed as the CuO concentration was increased in nanofibers. All samples exhibited antibacterial properties; however, the sample with CuO concentration of 0.6% exhibited better antibacterial activity. It was also observed that nanofibrous mats exhibited excellent cytocompatibility with fibroblast (NIH3T3) cells. The mechanical properties of nanofibers were slightly improved due to the addition of nanoparticles. By considering the excellent results of nanofibrous mats, they can therefore be recommended for wound dressing applications.

Fabrication and Characterization of Electrospun Folic Acid/Hybrid Fibers: In Vitro Controlled Release Study and Cytocompatibility Assays.

The fabrication of skin-care products with therapeutic properties has been significant for human health trends. In this study, we developed efficient hydrophilic composite nanofibers (NFs) loaded with the folic acid (FA) by electrospinning and electrospraying processes for tissue engineering or wound healing cosmetic applications. The morphological, chemical and thermal characteristics, in vitro release properties, and cytocompatibility of the resulting composite fibers with the same amount of folic acid were analyzed. The SEM micrographs indicate that the obtained nanofibers were in the nanometer range, with an average fiber diameter of 75-270 nm and a good porosity ratio (34-55%). The TGA curves show that FA inhibits the degradation of the polymer and acts as an antioxidant at high temperatures. More physical interaction between FA and matrices has been shown to occur in the electrospray process than in the electrospinning process. A UV-Vis in vitro study of FA-loaded electrospun fibers for 8 h in artificial acidic (pH 5.44) and alkaline (pH 8.04) sweat solutions exhibited a rapid release of FA-loaded electrospun fibers, showing the effect of polymer matrix-FA interactions and fabrication processes on their release from the nanofibers. PVA-CHi/FA webs have the highest release value, with 95.2% in alkaline media. In acidic media, the highest release (92%) occurred on the PVA-Gel-CHi/sFA sample, and this followed first-order and Korsmeyer-Peppas kinetic models. Further, the L929 cytocompatibility assay results pointed out that all NFs (with/without FA) generated had no cell toxicity; on the contrary, the FA in the fibers facilitates cell growth. Therefore, the nanofibers are a potential candidate material in skin-care and tissue engineering applications.

Evaluating Antibacterial Efficacy and Biocompatibility of PAN Nanofibers Loaded with Diclofenac Sodium Salt.

Side effects of the drugs' oral administration led us to examine the possibility of using diclofenac sodium (DLF) in a polymeric drug delivery system based on electrospun polyacrylonitrile (PAN) nanofibers, which can be produced cost-effectively and with good applicability for transdermal treatments. The inclusion of DLF in PAN nanofibers increased the nanofiber diameter from ~200 nm to ~500 nm. This increase can be attributed to the increase in the spinning solution viscosity. FTIR spectra confirm the entrapment of the DLF into the PAN nanofibers. X-ray diffraction pattern showed that the inclusion of the DLF in the PAN nanofibers had caused the misalignment in the polymeric chains of the PAN, thus resulting in a decrease of the peak intensity at 2θ = 17o. The DLF loaded PAN nanofibers were efficient against the gram-positive Staphylococcus aureus (S. aureus) and gram-negative Escherichia coli (E. coli), with maximum inhibition zone of 16 ± 0.46 mm for E. coli and 15.5 ± 0.28 mm for S. aureus. Good cell viability ~95% for L929 cells in more extended incubation periods was reported. A gradual release of DLF from the PAN nanofiber was observed and can be attributed to the stability of Pan in PBS medium. Cell adhesion micrographs show that cell-cell interaction is stronger than the cell-material interaction. This type of weak cell interaction with the wound dressing is particularly advantageous, as this will not disturb the wound surface during the nursing of the wound.

Carboxymethyl Cellulose (CMC) Based Electrospun Composite Nanofiber Mats for Food Packaging.

Cellulose is one of the most abundantly available natural polymers. Carboxymethyl cellulose (CMC) belongs to the cellulose family and has different degrees of substitution. Current research comprises the fabrication and characterization of CMC nanofibers using polyvinyl alcohol (PVA) and polyvinylpyrrolidone (PVP) as capping agents and carriers for sustainable food packaging applications. Recently authors successfully fabricated smooth and uniform nanofibers of stated polymers and optimized the ratios of three polymers for continuous production. However, in this research, it was further characterized for mechanical properties, surface properties, structural properties, air permeability, and chemical properties to confirm the suitability and scope of tri-component nanofibrous mats in food packaging applications. Different fruits and vegetables were packed in a plastic container and closed by nanofiber mats and by a plastic lid. All samples were observed after a specific period of time (fruits were kept for 40 days while vegetables were kept for 10 days in the controlled environment). It was observed in the results that fruits and vegetables closed by nanofiber based webs exhibited better freshness and lower accumulation of moisture as compared to that of containers with plastic lids. From the results of performed tests, it was observed that nanofiber mats possess enough mechanical, structural, and morphological properties to be used as food packaging.

Wet-spun bi-component alginate based hydrogel fibers: Development and in-vitro evaluation as a potential moist wound care dressing.

In this study, bi-component alginate-hyaluronic acid (AHA) fibers were developed by using two different routes. In the first method, sodium alginate dope solution was extruded into a coagulation bath containing CaCl2 and subsequently dip-coated with hyaluronic acid (HA) whereas, in the second method, hyaluronic acid-containing sodium alginate dope solution was directly extruded into CaCl2 bath. The resulting AHA fibers were then dehydrated in 25-100% v/v acetone solutions and dried in air. The fibers were characterized by surface morphology, physicochemical analysis, mechanical performance, swelling percentage, and total liquid absorption (g/g), cell viability, and release behavior. The results showed that AHA fibers produced by the second method have better mechanical performance, high liquid absorption, and swelling percentage with a more controlled release of hyaluronic acid. The AHA fibers showed high biocompatibility toward nHDF cell line in in-vitro testing, and the MVTR values (650-800 g/m2/day) are in a suitable range for maintaining a moist wound surface proving to be appropriate for promoting wound healing.

Optimized Loading of Carboxymethyl Cellulose (CMC) in Tri-component Electrospun Nanofibers Having Uniform Morphology.

Cellulose is one of the most hydrophilic polymers with sufficient water holding capacity but it is unstable in aqueous conditions and it swells. Cellulose itself is not suitable for electrospun nanofibers' formation due to high swelling, viscosity, and lower conductivity. Carboxymethyl cellulose (CMC) is also super hydrophilic polymer, however it has the same trend for nanofibers formation as that of cellulose. Due to the above-stated reasons, applications of CMC are quite limited in nanotechnology. In recent research, loading of CMC was optimized for electrospun tri-component polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), and carboxymethyl cellulose (CMC) nanofibers aim at widening its area of applications. PVA is a water-soluble polymer with a wide range of applications in water filtration, biomedical, and environmental engineering, and with the advantage of easy process ability. However, it was observed that only PVA was not sufficient to produce PVA/CMC nanofibers via electrospinning. To increase spinnability of PVA/CMC nanofibers, PVP was selected as the best available option because of its higher conductivity and water solubility. Weight ratios of CMC and PVP were optimized to produce uniform nanofibers with continuous production as well. It was observed that at a weight ratio of PVP 12 and CMC 3 was at the highest possible loading to produce smooth nanofibers.

Manuka honey incorporated cellulose acetate nanofibrous mats: Fabrication and in vitro evaluation as a potential wound dressing.

Wound dressings are the primary barrier between the wound surface and the outer environment. Here we report the fabrication of cellulose acetate (CA)-Manuka honey (MH) composite nanofibrous mats as a biocompatible and antimicrobial wound dressing. CA mats with different quantities of MH were developed by electrospinning. The ATR-FTIR spectra confirm the inclusion of MH in the composite CA-MH nanofibrous mats. The fibers were continuous and bead-free with acceptable mechanical properties. The fiber diameter increased with an increase in MH content. Inclusion of MH in the electrospun composite CA-MH nanofibrous mats shows high efficacy to prevent bacterial growth on the wound surface. The MH loaded CA nanofiber mats showed good antioxidant abilities, while the ability to free radicalize the DPPH was dependent upon the factors of MH content in the fiber and the time of immersion in the DPPH solution. Besides, the nanofibrous mat's high porosity (85-90%) and WVTR values of 2600 to 1950 g/m2/day, suitable for wound breathability and the mats show high cytocompatibility to NIH 3T3 cell line in in vitro testing, proving to be effective for promoting wound healing.

Reusability Comparison of Melt-Blown vs Nanofiber Face Mask Filters for Use in the Coronavirus Pandemic.

Shortage of face masks is a current critical concern since the emergence of coronavirus-2 or SARS-CoV-2 (COVID-19). In this work, we compared the melt-blown (MB) filter, which is commonly used for the N95 face mask, with nanofiber (NF) filter, which is gradually used as an effective mask filter, to evaluate their reusability. Extensive characterizations were performed repeatedly to evaluate some performance parameters, which include filtration efficiency, airflow rate, and surface and morphological properties, after two types of cleaning treatments. In the first cleaning type, samples were dipped in 75% ethanol for a predetermined duration. In the second cleaning type, 75% ethanol was sprayed on samples. It was found that filtration efficiency of MB filter was significantly dropped after treatment with ethanol, while the NF filter exhibited consistent high filtration efficiency regardless of cleaning types. In addition, the NF filter showed better cytocompatibility than the MB filter, demonstrating its harmlessness on the human body. Regardless of ethanol treatments, surfaces of both filter types maintained hydrophobicity, which can sufficiently prevent wetting by moisture and saliva splash to prohibit not only pathogen transmission but also bacterial growth inside. On the basis of these comparative evaluations, the wider use of the NF filter for face mask applications is highly recommended, and it can be reused multiple times with robust filtration efficiency. It would be greatly helpful to solve the current shortage issue of face masks and significantly improve safety for front line fighters against coronavirus disease.

Antibacterial properties of in situ and surface functionalized impregnation of silver sulfadiazine in polyacrylonitrile nanofiber mats.

BACKGROUND: Silver, incorporation with natural or synthetic polymers, has been used as an effective antibacterial agent since decades. Silver has potential applications in healthcare especially in nanoparticles form but silver sulfadiazine (AgSD) is the most efficient antibacterial agent especially for burn wound dressings. METHOD: In this report, mechanical, structural, and antibacterial properties of PAN nanofibers incorporation with silver sulfadiazine are mainly focused. AgSD was loaded for the first time on electrospinning as well as self-synthesized AgSD on PAN nanofibers by solution immersion method and then compared the results of both. RESULTS: Occurrence of chemical reaction among the functional groups of AgSD and PAN were analyzed using FTIR, for both types of specimen. Morphological and surface properties of prepared nanofiber mats were characterized by scanning electron microscope, and it resulted in uniform nanofibers without bead formation. Diameter of nanofibers was slightly increased with addition of AgSD by in situ and immersion methods respectively. Nanoparticles distribution was analyzed by transmission electron microscopy. Thermal properties were analyzed by thermo-gravimetric analyzer and it was observed that AgSD decreased thermal stability of PAN which is better from biomedical perspective. X-ray diffraction declared crystalline structure of nanofiber mats. Presence of Ag and S contents in nanofiber mats was analyzed by X-ray photo spectroscopy. Antibacterial properties of nanofiber mats were investigated by disc diffusion method was carried out. E. coli and Bacillus bacteria strain were used as gram-negative and gram-positive respectively. Zone inhibition of the bacteria was used as a tool to determine effectiveness of AgSD released from PAN nanofiber mats. The antibacterial properties of PAN nanofibers impregnated with AgSD were determined with both types of bacteria strains to compare with control one. CONCLUSION: On the basis of characterization results it is concluded that PAN/AgSD (immersion) nanofiber mats have better structural and antibacterial properties than that of PAN/AgSD (in situ) nanofiber mats. So, from our point of view, self-synthesized AgSD is recommended for further production of nanofiber mats for antibacterial applications.

Silver sulfadiazine loaded zein nanofiber mats as a novel wound dressing.

In this report a novel antibacterial wound dressing was prepared and then characterized for required testing. We loaded silver sulfadiazine (AgSD) for the first time by electrospinning. AgSD was added in zein (0.3%, 0.4%, 0.5%, and 0.6% by weight) and was electrospun to fabricate nanofiber mats for wound dressings. Nanofiber mats were characterized by Fourier transform infrared spectroscopy (FTIR) to check if there was any chemical reaction between AgSD and zein. Morphological properties were analyzed by Scanning Electron Microscopy (SEM), which showed uniform nanofibers without any bead formation. The diameter of the nanofibers gradually decreased with an increase in the amount of AgSD, which can be associated with strong physical bonding between zein and AgSD. Thermal properties of nanofiber mats were analyzed by Thermogravimetric Analysis (TGA). X-Ray Diffraction (XRD) further demonstrated the crystalline structure of the nanofiber mats, and X-ray Photoelectron spectroscopy (XPS) was performed to confirm Ag and S contents in the prepared wound dressings. In order to investigate antibacterial properties, a disc diffusion method was employed. Bacillus and E. coli bacteria strains were used as Gram-positive and Gram-negative strains respectively. The antibacterial effectiveness of AgSD released from zein nanofibers was determined from the zone inhibition of the bacteria. The antibacterial activity of zein nanofibers loaded with drug was observed with both strains of bacteria in comparison to a control. Excellent antibacterial efficacy was attributed to the sample with 0.6% AgSD. Excellent release properties were also associated with the sample with 0.6% AgSD in zein nanofibers. Keeping in mind the abovementioned characteristics, prepared nanofiber mats would be effective for application in wound dressings.