Nanospider Technology for the Production of Nylon-6 Nanofibers for Biomedical Applications

Nylon-6 nanofiber mat incorporated with 5,5-dimethyl hydantoin (DMH) as an antimicrobial drug was electrospun from formic acid. The morphology of the nanofiber mat using scanning electron microscope (SEM) showed that the obtained fiber had an average diameter of around 15–328 nm. The nanofiber was characterized by FTIR spectra, TGA, and DSC. The nanofiber containing drug showed initial fast release. It released about 55% of its drug content within the first two hours. Moreover, the antimicrobial activity of the electrospun nylon-6 nanofiber containing drug was examined against Escherichia coli, Pseudomonas aeruginosa, Aspergillus niger, and Aspergillus flavus. The nylon-6 nanofiber exhibited high inhibitory effects against the microbes. The results clearly indicate that the antimicrobial activity of the electrospun nylon-6 nanofiber containing drug varies with the species of the organisms used. Thus, the study ascertains the value of the use of electrospun nanofiber, which could be of considerable interest to the development of new antimicrobial materials. The microbes, examined by SEM, were totally deformed and exhibited severe destruction. Abnormal cell division was observed at high frequencies among cells that tried to divide in the presence of the nanofiber. Many cells were enlarged, elongated, empty ghosts, or fragmented, consistent with the extremely low viability

Superabsorbent composites based on rice husk for agricultural applications: Swelling behavior, biodegradability in soil and drought alleviation

Abstract Low-cost composites with high water absorption capacity were prepared by free radical copolymerization of acrylic acid (AA), acrylamide (AM) and gelatin in aqueous media using N,N' methylene bis-acrylamide (MBA) as crosslinker, potassium persulfate (KPS) as initiator and rice husk (RH) as a filler. The composites were characterized by Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The effects of different parameters such as the alkaline treatment on the rice husk, the media pH and salinity and the composition of the composites on their water absorption capacity were investigated. The water retention and biodegradation tests in soil were also carried out. The optimized composite containing treated RH showed a maximum water uptake value of 825 g∙g−1 in distilled water and good resistance in saline solutions and in the pH range of 6–10. Positive effects on the soil water retention were obtained after 30 days samples of soil containing 1 wt% of superabsorbent composites still contained about 7% of the initial absorbed water. Growth attributes, photosynthetic pigments and nodulation traits of droughted peanut were improved by 60 kg∙ha−1 dosage of SAC. On the basis of the good results of water retention and controlled biodegradability in the soil, the developed composites have the potential to be used in agriculture for better water management, with relevant environmental benefits

Preparation of organophilic montmorillonite-based dimethylamino benzaldehyde-Schiff-base as antibacterial agents

New antibacterial composites were synthesized by modification and functionalization of montmorillonite (MMT). The antibacterial composites were synthesized by the reaction of MMT clay with the quaternary salt of p-N,N-dimethylamino benzaldehyde which produced modified functionalized montmorillonite composite in the form of Schiff bases. The Schiff bases (4–11) were obtained by the reaction of functionalized montmorillonite with various amines namely o-anisidine, anthranilic acid, p-carboxy aniline, p-methyl aniline, p-methoxy aniline, p-hydroxy aniline, p-nitro aniline and p-phenylene diamine. The structures of the newly prepared composites were elucidated by Fourier transform infra red (FT-IR), thermal gravimetric analysis (TGA) and X-ray diffraction (XRD). The antibacterial activities of these composites were investigated by the ‘cut plug’ method against Gram-negative bacteria such as Escherichia coli, Serratia marcescens, Enterobacter cloacae, Shigella dysenteriae, Salmonella enterica and Proteus vulgaris, and Gram-positive such as Bacillus subtilis and Staphylococcus aureus which showed high antimicrobial activities at relatively low concentrations (2.5–20 mg/mL). These promising results pave the way in the future to use the newly synthesized composites as antibacterial agents for water treatment against pathogenic bacteria which exist in polluted water courses. Keywords: Antimicrobial activities, Montmorillonite, p-N,N-dimethylamino benzaldehyde, Water treatment, Schiff base

Controlled Release of 5-Aminosalicylic Acid (5-ASA) from New Biodegradable Polyurethanes

Segmented polyurethanes containing azo aromatic groups in the main chain were synthesized by reaction of 3,3'-azobis(6-hydroxybenzoic acid) (ABHB), 5-[4-(hydroxyphenyl)azo] salicylic acid (HPAS), and 5-[1-hydroxynaphthyl)azo] salicylic acid (HNAS) with hexamethylenediisocyanate (HDI). All synthesized monomers and polymers were characterized by elemental analysis, FTIR, 1H-NMR spectra, TGA and DSC analysis. All the synthesized azo polymers showed good thermal stability and the onset decomposition temperature of all these polymers was found to be above 195 ºC under nitrogen atmosphere.The release of 5-ASA under physiological conditions (pH = 7.8 and pH = 1.5) was investigated at body temperature (37 ºC). The release rate of 5-ASA increased with increasing pH (i.e., 7.8 > 1.5)

Preparation of organophilic montmorillonite-based dimethylamino benzaldehyde-Schiff-base as antibacterial agents

AbstractNew antibacterial composites were synthesized by modification and functionalization of montmorillonite (MMT). The antibacterial composites were synthesized by the reaction of MMT clay with the quaternary salt of p-N,N-dimethylamino benzaldehyde which produced modified functionalized montmorillonite composite in the form of Schiff bases. The Schiff bases (4–11) were obtained by the reaction of functionalized montmorillonite with various amines namely o-anisidine, anthranilic acid, p-carboxy aniline, p-methyl aniline, p-methoxy aniline, p-hydroxy aniline, p-nitro aniline and p-phenylene diamine. The structures of the newly prepared composites were elucidated by Fourier transform infra red (FT-IR), thermal gravimetric analysis (TGA) and X-ray diffraction (XRD). The antibacterial activities of these composites were investigated by the ‘cut plug’ method against Gram-negative bacteria such as Escherichia coli, Serratia marcescens, Enterobacter cloacae, Shigella dysenteriae, Salmonella enterica and Proteus vulgaris, and Gram-positive such as Bacillus subtilis and Staphylococcus aureus which showed high antimicrobial activities at relatively low concentrations (2.5–20mg/mL). These promising results pave the way in the future to use the newly synthesized composites as antibacterial agents for water treatment against pathogenic bacteria which exist in polluted water courses

A review on polymeric hydrogel membranes for wound dressing applications: PVA-based hydrogel dressings

This review presents the past and current efforts with a brief description on the featured properties of hydrogel membranes fabricated from biopolymers and synthetic ones for wound dressing applications. Many endeavors have been exerted during past ten years for developing new artificial polymeric membranes, which fulfill the demanded conditions for the treatment of skin wounds. This review mainly focuses on representing specifications of ideal polymeric wound dressing membranes, such as crosslinked hydrogels compatible with wound dressing purposes. But as the hydrogels with single component have low mechanical strength, recent trends have offered composite or hybrid hydrogel membranes to achieve the typical wound dressing requirements

Microwave-assisted of new derivatives of polyimine conjugated polymer based on Schiff base: synthesis, characterization, and photo-physical properties as a photoluminescent materials

Abstract The condensation of pyrrole-2,5-dicarbaldehyde (1) with 5-(2-amino-4-phenylthiazol-5-yl)-4-phenylthiazol-2-amine (2) and/or 5-(4-Amino-phenyl)-4-phenylthiazol-2-amine (3) gave new poly(Z)-N-((5-(iminomethyl)-1H-pyrrol-2-yl)methylene)-5-(2-((E)-(5-(iminomethyl)-I-pyrrol-2-yl)methyleneamino)-4-phenylthiazol-5-yl)-4-phenylthiaol-2-amine (P1) and/or poly(E)-N-((5-(iminomethyl)-1H-pyrrol-2-yl)methylene)-5-(4-((E)-(5-(iminomethyl)-1H-pyrrol-2-yl)methyleneamino)phenyl)-4-phenylthiaol-2-amine (P2) as a novel conjugated polymer by microwave irradiation and traditional heating.. It is evident that the microwave irradiation technique quickly raised the molecular weight of polyimines. In addition to quantifying the molecular weight of the resultant polyimines. All the polyimines were characterized using FTIR, XRD, H1NMR, TGA, and DSC. The optical characteristics of polyimine derivatives were investigated using a UV–Vis spectrophotometer. The absorption spectra showed a main absorption band around 372 nm for polyimine (P1) and 381 nm for polyimine (P2). The optical energy was calculated and found to be 2.49 and 2.68 eV. The photoluminescence of the polyimine derivatives was measured and analyzed by spectrofluorometer and Laser photoluminescence experiment and the emission color was studied using CIE graphs. The fluorescence spectra showed an emission peak at 548 nm for polyimine (P1) with yellow green color in CIE graph, while for polyimine (P2) the emission band was located at 440.5 nm with blue color in CIE graph. Photoluminescence quantum yield PLQY was measured for the polyimine P1 and P2 in both liquid and Solid states and indicated the AIE behavior of the polyimines. TD-DFT simulations were applied to the polyimine derivatives where the structures were geometrically optimized and the spectroscopic characterizations were evaluated

Biosynthesis of cellulose from Ulva lactuca, manufacture of nanocellulose and its application as antimicrobial polymer

Abstract Green nanotechnology has recently been recognized as a more proper and safer tool for medical applications thanks to its natural reductions with low toxicity and avoidance of injurious chemicals. The macroalgal biomass was used for nanocellulose biosynthesis. Algae are abundant in the environment and have a high content of cellulose. In our study, we extracted parent cellulose from Ulva lactuca where consecutive treatments extracted cellulose to obtain an insoluble fraction rich in cellulose. The extracted cellulose has the same results obtained by matching it with reference cellulose, especially the same Fourier transform infrared (FTIR) and X-Ray diffraction (XRD) analysis peaks. Nanocellulose was synthesized from extracted cellulose with hydrolysis by sulfuric acid. Nanocellulose was examined by Scanning electron microscope (SEM) shown by a slab-like region as Fig. 4a and Energy dispersive X-ray (EDX) to examine the chemical composition. The size of nanocellulose in the range of 50 nm is calculated by XRD analysis. Antibacterial examination of nanocellulose was tested against Gram+ bacteria like Staphylococcus aureus (ATCC6538), Klebsiella pneumonia (ST627), and Gram-negative bacteria such as Escherichia coli (ATCC25922), and coagulase-negative Staphylococci (CoNS) to give 4.06, 4.66, 4.93 and 4.43 cm as respectively. Comparing the antibacterial effect of nanocellulose with some antibiotics and estimating minimal Inhibitory Concentration (MIC) of nanocellulose. We tested the influence of cellulose and nanocellulose on some fungi such as Aspergillus flavus, Candida albicans, and Candida tropicalis. These results demonstrate that nanocellulose could be developed as an excellent solution to these challenges, making nanocellulose extracted from natural algae a very important medical material that is compatible with sustainable development

Ammonium salts of microcrystalline cellulose-g-poly (acrylonitrile) : toxicity, antioxidant and anti-inflammatory properties

Cellulose is an excellent starting material for the construction of bioactive polymers. In the present work, we have synthesized quaternized graft copolymers of cellulose and tested their biological properties. Cellulose was grafted with acrylonitrile in a cerium ion catalyzed reaction. High yield of the grafting reaction, 89%, was achieved. Next, the poly (acrylonitrile) chains were aminated using three different amines and finally, the amino functions were quaternized using methyl iodide. In addition to chemical and physical characterization of the polymers, several tests on their bioactive properties have been conducted. The polymers turned out to have good antioxidant properties, as assessed studying how they scavenge ABTS radicals. Anti-inflammatory properties were investigated by a membrane stabilization method. The results showed that the quaternized polymers had anti-inflammatory effects and the one aminated with tris(2-aminoethyl)amine was the most significant compared with indomethacin. The cytotoxicity was evaluated in vitro against HepG2 and WI-38 cell lines. All quaternized polymers showed moderate effects against the cancerous cell line HEPG2. On the other hand, their effect against normal fibroblast WI-38 was weak. The acute toxicity in vivo was evaluated for one of the polymers, for which the LD50 was 6606 mg/kg. The high LD50 indicates the polymer is relatively non-toxic, and will be considered in future for in vivo studies.Peer reviewe