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Biofilm and bionanocomposite films were synthesized from polyvinylpyrrolidone (PVP), chitosan (CS), citric acid (CA), and zinc oxide-nanoparticles (ZnO-NPs). Effects of gamma-irradiation dose and ZnO-NPs concentrations; 0, 0.1, 0.3, 0.6, 0.9, 1.2, and 1.5 (wt/wt,)% were studied. Biofilms and bionanocomposite films were characterized by Fourier transform infrared, Raman spectroscopy, transmission electron microscopy, thermal gravimetric analysis, X-rays diffraction, energy dispersive X-ray, and mechanical properties to identify structure of biofilm and bionanocomposite films. Swelling (g/g)% and gelation (g/g)% of biofilms were carried out at diverse compositions of PVP to CS of (1/1), (1/2), and (2/1) (v/v). Swelling (g/g)% results of (1/1), (1/2), and (2/1) (v/v) were 116, 110, and 126, respectively. Values of highest and lowest gelation (g/g)% of (1/2) and (2/1) (v/v) are 98.0 [+ or -] 1.8 and 85.0 [+ or -] 2.6, respectively at 30 kGy. Water vapor transmission rate was studied for films and exposed 3450 [+ or -] 4.1 and 185.8 [+ or -] 1.2 (kg/[m.sup.2]. day) for open bottle and (PVP/CS/PCA)/(ZnO-NPs-1.5), respectively. Values of water solubility (g/g)% were investigated and found 30.21 [+ or -] 1.3 and 15.4 [+ or -] 2.5 for (PVP/CS/PCA)/(ZnO-NPs-0) and (PVP/CS/PCA)/(ZnO-NPs-1.5), accordingly. Bionanocomposite films displayed a broad-spectrum antimicrobial activity against Gram-negative bacteria and Gram-positive bacteria. (PVP/CS/PCA)/(ZnO-NPs-0.1) showed lowest inhibition zone; 4 [+ or -] 0.2, 9 [+ or -] 0.5, 19 [+ or -] 0.1, and 8 [+ or -] 0.3 (mm) compared with (PVP/CS/PCA)/(ZnO-NPs-1.5) of highest inhibition zone; 16 [+ or -] 0.5, 28 [+ or -] 0.2, 33 [+ or -] 0.6, and 18 [+ or -] 0.3 (mm) for Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, and Staphylococcus aureus, respectively. Antimicrobial activity increased with increasing ZnO-NPs concentrations. Biodegradation of biofilms and bionanocomposite films were examined under soil from 0 to 120 days. Results of weight loss (g/g)% at 120 days of (PVP/CS/PCA)/(ZnO-NPs-0) and (PVP/CS/PCA)/(ZnO-NPs-1.5) are 72 [+ or -] 4.5 and 47.5 [+ or -] 3.8, respectively. Bionanocomposite films were used in food preservation of fresh cherry tomatoes for 30 days and showed goodness. Therefore, these results suggest that the possibility of using bionanocomposite films in food-packaging applications. Highlights * Synthesis of development of (polyvinylpyrrolidone/chitsoan/citric acid)/ (zinc oxide-nanoparticles) bionanocomposite films. * Characterization of bionanocomposite films by different techniques. * Study of biodegradation of bionanocomposite films. * Study of antimicrobial of bionanocomposite films. * Usage of bionanocomposite films in cherry tomatoes preservation for 30 days. KEYWORDS antimicrobial, biodegradability, cherry tomatoes preservation, gamma irradiation, nanocomposites, 1 | INTRODUCTION The headache trouble of nonbiodegradable polymeric wastes has really become a terrible and horrible issue in recent years with catastrophic impacts on environmental. Biodegradable polymers are deemed [...]

Carboxymethyl cellulose (CMC)/titanium dioxide (TiO2) was prepared using gamma irradiation at different doses. Carboxymethyl cellulose was used as a matrix and TiO2 in different contents was added (0.25, 0.5, 1, 1.5 wt%) as a filler. The polymer composite films were irradiated at doses of 5, 10 and 15 kGy using 60Co γ-ray to form crosslinked network structure. The prepared composite films were described by different diagnostic procedures including X-ray diffractometer, scanning electron microscope (SEM), FTIR as well as thermal and mechanical properties measurements. CMC/TiO2 composite films were used for removal of basic Violet 7 dye. The adsorption of the dye match with the Langmuir model across chemical monolayer adsorption performance. Adsorption kinetic of dyes was set up to be regular to pseudo second order kinetic model. The results showed that the prepared composite films significantly removed this basic violet 7 dye with maximum absorption capacity (123.6 mg/g). [ABSTRACT FROM AUTHOR]

Modification of low density polyethylene (LDPE) films by blending with Polylactic acid (PLA) and Starch (St) were carried out. Also, the study describes the comparison of two curing methods one by thermal curing at 70°C and the other is radiation curing at dose 20 kGy for the bioblend film composed of LDPE/PLA/St with composition (98%:1%:1% wt%). The efficiency of modification was determined by using different devices such as Fourier transform infrared (FTIR), mechanical, TGA, and XRD. In addition, the properties of the different bioblends were compared with other synthetic polymers such as commercial LDPE and blank LDPE. The results show that the improved properties of radiation cured method at dose 20 kGy than thermal treatment method at 70°C. The radiation cured bioblend film show good thermal stability either shown by the TGA results or against heating aging from ambient temperature up to 60°C than thermally treated blend film at 70°C. The radiation cured bioblend film found to be stable against UV‐ exposure with increasing time of exposure up to 30 min at higher wavelength (λ = 320 nm), which simulate ultraviolet radiation from sunshine. The modified properties of prepared radiation cured bioblend film are due to increase in interfacial adhesion bond between LDPE, PLA, and Starch by effect of irradiation dose at 20 kGy. The modified radiation cured bioblend films at 20 kGy can be applied in different fields such as packaging due to improvement in chemical, thermal, and mechanical properties that could partially replace the traditional petrochemical plastics. [ABSTRACT FROM AUTHOR]

The purpose of the current study is to prepare chitosan nanoparticles by gamma radiation as a new brain delivery system for memantine to improve its therapeutic efficiency. Fourier-transform infrared analysis of chitosan nanoparticles showed the characteristic peaks of chitosan and the reduction of particle size induced by irradiation at doses 10, 20 and 30 kGy. The solubility of chitosan nanoparticles was tested using different solvents and exhibited good solubility in both water and 1% acetic acid than other tested solvents at 80°C. Different formulations containing memantine - loaded chitosan nanoparticles were evaluated for brain targeting on aluminum-induced Alzheimer's disease in rats. Memory deficit was evaluated using the Morris water maze test. The levels of amyloid-β peptide, tumour necrosis factor alpha, interleukin-1β and interleukin-6 in brain tissues as well as the serum level of brain-derived neurotrophic factor were assayed. Data demonstrated that memantine - loaded chitosan nanoparticles 1:1 transported memantine effectively into the brain compared to free memantine as evidenced by better behaviour performance and biochemical amelioration and confirmed by histopathological examination in Alzheimer's disease rats. Interestingly, the therapeutic effect of memantine - loaded chitosan nanoparticles 1:1 was superior to memantine - loaded chitosan nanoparticles 1:2 and memantine - loaded chitosan nanoparticles 2:1. Based on these findings, it is reasonable to suggest that memantine - loaded chitosan nanoparticles 1:1 could be a promising approach for Alzheimer's disease. [ABSTRACT FROM AUTHOR]

Synthesis of nanoparticles with antibacterial properties is of great interest for the development of textiles finishing, in general, and cotton fabric, in particular. In this work, TiO2nanoparticles at different concentrations were synthesized using nitric acid as a reducing and stabilizing agent. Cotton fabrics were first impregnated, to a pick-up of 100%, in colloidal solutions containing carboxymethyl cellulose (CMC)/polyvinyl alcohol(PVA)/TiO2nanocomposites. After that, the coated fabrics were exposed to gamma irradiation to produce TiO2nanoparticles stabilized in cross-linked CMC/PVA hydrogel. The formation of TiO2nanoparticles was confirmed by ultra violet/visible (UV/vis) and transmission electron microscopy, and the particle size distribution of the nanoparticles was determined using the dynamic light scattering. The surface morphology of the finished fabrics was examined by scanning electron microscopy (SEM). The SEM micrographs revealed that TiO2nanoparticles were deposited on the surface of cotton fibers. The antibacterial activity of the treated fabrics loaded with TiO2nanoparticles was evaluated againstEscherichia coli(Gram -ve) bacteria. [ABSTRACT FROM PUBLISHER]