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Nanoparticles are frequently used as targeting delivery systems for therapeutic and diagnostic radiopharmaceuticals. Polyethylene oxide-polyacrylic acid (PEO-PAAc) nanogel was prepared via γ-radiation-induced polymerization. Variable factors affecting nanoparticles size were investigated. The nanogel was radiolabeled with the imaging radioisotope 99m Tc and finally conjugated with folic acid to target folate receptor actively. PEO-PAAc-folic acid gel was characterized by dynamic light scattering (DLS) and atomic force microscopy (AFM). Biodistribution was studied in normal mice and solid tumor-bearing mice via intravenous and intratumor injections of the radiolabeled PEO-PAAc-folic acid nanogel. Results of biodistribution showed high selective uptake of the prepared complex in tumor muscle compared with normal muscle for both intravenous and intratumor injections. The T/NT ratio was found to be 6.186 and 294.5 for intravenous and intratumor injections, respectively. Consequently, 99m Tc-PEO-PAAc-folic acid complex could be a promising agent for cancer diagnostic imaging.

Nanoparticles are frequently used as targeting delivery systems for therapeutic and diagnostic radiopharmaceuticals. Polyethylene oxide-polyacrylic acid (PEO-PAAc) nanogel was prepared via γ-radiation-induced polymerization. Variable factors affecting nanoparticles size were investigated. The nanogel was radiolabeled with the imaging radioisotope

Aim of the work: Resveratrol (RSV) is a phytoalexin with potent anti-inflammatory and anti-oxidant properties; however, its low bioavailability is considered a major obstacle. Piperine (PIP), an alkaloid, has been widely used as an effective bio-enhancer with drugs associated with low bioavailability. The current study was directed to examine the role of PIP in enhancing the efficacy of RSV in adjuvant-induced arthritis (AIA) in rats. Materials and methods: Carrageenan-induced paw edema model was designed for RSV and PIP doses optimization. Afterward, in the AIA model, rats were immunized at day 0 by sub-plantar injection of Freund’s complete-adjuvant. RSV (50 mg/kg) and PIP (20 mg/kg) were orally administered concurrently once daily from day 14 for two weeks. A standard anti-inflammatory drug, diclofenac, was employed for treatment validation. The paw volume was measured every 4 days. On day 29, rats were sacrificed and serum tumor necrosis factor-alpha (TNF-α), interleukin-1beta (IL-1β), thiobarbituric acid reactive substances (TBARS) and total nitrate/nitrite (NOx) were estimated. Ankles were dissected for histopathological examinations and immuno-histochemical expression of nuclear factor-kappa B p65 (NF-κB p65). Results: Co-administration of RSV and PIP significantly decreased the paw swelling and ameliorated the histopathological changes. In addition, the combined treatment highly reduced the serum TNF-α, IL-1β, TBARS and NOx. Besides, a nearly negative expression of NF-κB p65 in the synovial tissue was observed by co-administration of PIP with RSV. Results of the combination treatment were comparable to that of the diclofenac treatment. Conclusion: Co-administration of PIP enhanced the anti-inflammatory efficacy of RSV in the arthritic-induced rats. Keywords: Adjuvant-induced arthritis, Resveratrol, Piperine, Inflammation, Cytokines, Oxidative stress

We investigated the effect of gamma irradiation on the properties of low-density polyethylene composite films incorporated with the antimicrobial terpene 4-allylanisole (ALY), and the volatile release of ALY. For comparison, wood flour and molecular sieves were used as solid carriers for ALY at loading ratios of 20 and 30 wt.%. Infrared spectroscopy indicated that a proportion of ALY underwent structural change during melt-compounding and irradiation at high doses (> 10 kGy). Thermal and mechanical properties of composites prepared did not alter remarkably after irradiation. The release study of ALY showed that using wood flour and irradiation reduced the volatilization of ALY from the polymer matrix; however, the effect exerted by irradiation treatment was less noticeable than that of the carrier type. The antibacterial activity study demonstrated that irradiation only exerted a pronounced negative effect on samples that contained 30 wt.% of ALY/wood flour when irradiated at 30 and 50 kGy.

Purpose: Low dose radiation has been reported as an effective treatment for rheumatoid arthritis via multiple dose exposures. The present study was designed to increase the therapeutic efficacy of ...

Nanocomposite films based on cellulose acetate-polyethylene glycol/clay were prepared by solvent-casting technique. In order to improve the quality of nanocomposite films, 10 kGy gamma irradiation was used. The structure and morphology of the nanocomposite films were investigated by FT-IR, XRD and SEM. Moreover, the effect of clay and PEG contents on mechanical properties, oxygen and water permeability was studied. The results showed significant changes in the opacity index, mechanical properties, and water and oxygen permeability with respect to clay and PEG contents. The prepared nanocomposites showed intercalation of cellulose acetate inside the clay structure that caused a reduction of water vapor transmission rate (WVTR) and oxygen transmission rate (OTR) compared to pure cellulose acetate. The results showed that the prepared nanocomposite films could be used for packaging applications.

Clean and green reduction of graphene oxide (GO) to graphene (GR) nanosheets was achieved by gamma irradiation. The reduction efficiency was evaluated using UV–vis spectra. The effects of gas atmosphere, pH value of the dispersion medium, type of capping agent and absorbed dose on GR nanosheet formation were studied. Sodium carboxymethyl cellulose, ethyl hydroxyethyl cellulose, glucose and polyvinyl alcohol were investigated as capping agents. The presence of such one of them was proven to be crucial. The GR nanosheets obtained were characterized using AFM, TEM, FTIR, XRD, TGA and DSC. Effectiveness, simplicity, reproducibility, and low energy consumption are the merits of this technique.

Foodborne diseases have always been a threat to human health. Recently, food industries have shown great interest in developing essential oils-based nanoemulsion to suppress the virulence and biofilm formation that lead to substantial economic and health problems. Focusing this issue, we attempted a novel stable gamma irradiated bioactive coated thyme-based nanoemulsion (TCP nanoemulsion) stabilized by polyvinylpyrrolidone (PVP) using sonication technique and coated with chitosan. The impact of PVP and the irradiation dose on the formation, mean droplet diameter, zeta potential, physicochemical stability and long-term storage stability were investigated. Optimum results were obtained for 0.5 PVP% and irradiated at 2 kGy, which developed a nanoemulsion with an average droplet diameter of 13 nm and zeta potential of −48 mV. The screening of antimicrobial activity and biofilm inhibition and removal against four tested microbial strains was done. TCP exhibited antimicrobial activity against all tested strains with variable extent. Moreover, it was effective in biofilm inhibition of different strains. The percentages of biofilm removal after 10 min treatment with TCP were considerable. Hence, the TCP was promising as antibiofilm and antimicrobial agents for food industries.

Superabsorbent hydrogels based on polyacrylamide (PAAm) and Na-alginate (Alg) or chitosan (CS) were synthesized by γ-rays. The effect of dose and copolymer composition on gel content and water absorbency of PAAm/Alg, PAAm/CS and PAAm/Alg/CS hydrogels were studied. The gel content and water absorbency follows the order PAAm/Alg > PAAm/Alg/CS > PAAm/CS. The effect of different cations, fertilizers, buffers on water absorbency of the hydrogels was investigated. Water retention capability of swollen hydrogels as a function of time was studied. PAAm/Alg hydrogel has a high water retention capability. An application of the prepared hydrogels in agricultural fields was performed using maize plants. The results showed that the presence of hydrogels had growth promotion effect on quality and quantity of maize plants. The plants treated by PAAm/Alg hydrogels showed 50% increase in the grain yield suggesting their possible use as a soil conditioner and a water reservoir for plant-soil system.

Poly(lactic acid) (PLA) has shown much success in the preparation of tissue engineering scaffolds as it can be fabricated with a tailored architecture. However, the PLA surface has drawbacks including the lack of biofunctional motifs which are essential for high affinity to biological cells. Therefore, this study describes a multistep physicochemical approach for the immobilization of d-glucosamine (GlcN), a naturally occurring monosaccharide having many biological functions, on the PLA surface aiming at enhancing the cell proliferation activity. In this approach, poly(acrylic acid) (PAAc) spacer arms are first introduced into the PLA surface via plasma post-irradiation grafting technique. Then, covalent coupling or physical adsorption of GlcN with/on the PAAc spacer is carried out. Factors affecting the grafting yield are controlled to produce a suitable spacer for bioimmobilization. X-ray photon spectroscopic (XPS) analyses confirm the immobilization of GlcN on the PLA surface. The XPS results reveal also that increasing the yield of grafted PAAc spacer on the PLA surface increases the amount of covalently immobilized GlcN, but actually inhibits the immobilization process using the physical adsorption method. Contact angle measurements and atomic force microscopy (AFM) show a substantial increase of surface energy and roughness of PLA surface, respectively, upon the multistep modification procedure. The cytocompatibility of the modified surfaces is assessed using a mouse embryonic fibroblast (MEF) cell line. Observation from the cell culture basically demonstrates the potential of GlcN immobilization in improving the cytocompatibility of the PLA surface. Moreover, the covalent immobilization of GlcN seems to produce more cytocompatible surfaces if compared with the physical adsorption method. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 3176-3188, 2017.

The present work reports a nanotechnology strategy to prepare a low-viscosity poly(acrylic acid) (PAAc)-based tear substitute with enhanced efficacy and compliance. Specifically, nanogels composed of PAAc and polyvinylpyrrolidone (PVP) were prepared by adapting an ionizing radiation method. For this purpose, different aqueous systems: PVP/PAAc nanoparticulate complexes, PVP/acrylic acid (AAc), N-vinylpyrrolidone (N-VP)/PAAc, and N-VP/AAc were exposed to gamma rays. The dynamic light scattering technique showed that stable nanogels are only produced in a relatively high yield from the PVP/AAc system. Nanogel formation was driven by the hydrogen-bonding complexation between PVP and PAAc (formed in situ) as well as the radiation-induced cross-linking. Transparency, viscosity and mucoadhesiveness of emerged nanogels were optimized by controlling the feed composition and irradiation dose. Furthermore, neutralized nanogels were topically applied in a dry eye model and compared with a PAAc-based commercial tear substitute, namely Vidisic® Gel. The results of Schirmer's test and tear break-up time demonstrated that nanogels prepared from AAc-rich feed solutions at 20 kGy enhanced markedly the dry eye conditions. The histopathological analysis also ensured the competence of PAAc-rich nanogels to completely return the corneal epithelium to its normal state.

Gamma irradiation was used as an effective and “eco-friendly” route for production of graphene sheets. The corrosion behavior of AISI 316 steel coated with gamma irradiated graphene (GIG) and its composites containing different concentrations of an organic inhibitor was evaluated in 0.5 M sulfuric acid solution. TEM and FTIR spectroscopy confirmed the successful incorporation of inhibitor molecules into the GIG matrix. Potentiodynamic polarization indicated the protection efficiency offered by GIG coatings which was enhanced upon using the inhibitor with GIG. The protection efficiency increased (up to 95.8%) with increasing the inhibitor concentration with an optimum concentration of 2 mM. EIS measurements confirmed the stability of the coatings after prolonged immersion time in solution. FE-SEM was used to study the surface morphology of the coatings.

In-situ generation of a nanodispersed conductive polymer within a polypropylene matrix has been pursued in order to obtain flexible, conductive films. Radiation grafting of acrylic acid to polypropylene (PP) has been applied to insert carboxyl functionalities on PP. The radiation-grafted films have been further derivatized with a variety of diamines and used as substrates for in-situ chemical oxidative polymerization of polyaniline (PANI). PANI grows as a thin skin from the surface of the film as well as an interpenetrated network in its interiors. Evidence of chemical attachment of PANI to PP has been sought by performing FTIR and XPS analyses after extraction of the unbound polymer. The influence of the nature of the substituent attached to PP on the optical and electrical properties of the films has been investigated. PANI-PP skin-core films have been also tested as flexible electrodes for further electrochemical growth of the conductive polymer.

In this work we demonstrated the effective use of gamma irradiation for useful chemical conversion. Thus, graphene oxide was reduced to graphene upon exposure to gamma irradiation. The resulting gamma irradiated graphene (GIG) and graphene-covered steel were characterized using UV-Vis, XRD spectroscopies and FE-SEM. Corrosion protection of austenitic stainless steel AISI 316 by GIG and gamma irradiated graphene/chitosan (GIG/CS) composite films in 3.5% NaCl solution was investigated using potentiodynamic polarization and electrochemical impedance spectroscopy. The protection efficiencies for GIG and GIG/CS were 82.2% and 89%, respectively. GIG/CS films over steel showed higher corrosion activation energies compared to GIG. EIS proved the stability of GIG and GIG/CS coatings after different immersion times in 3.5% NaCl solution. Coated surfaces were free from pits on the scale of magnification as demonstrated from SEM images. The pitting corrosion behavior of uncoated and GIG-coated surfaces was also studied.

Poly(lactic acid) (PLA) has shown much success in the preparation of tissue engineering scaffolds as it can be fabricated with a tailored architecture. However, the PLA surface has drawbacks including the lack of biofunctional motifs which are essential for high affinity to biological cells. Therefore, this study describes a multistep physicochemical approach for the immobilization of d-glucosamine (GlcN), a naturally occurring monosaccharide having many biological functions, on the PLA surface aiming at enhancing the cell proliferation activity. In this approach, poly(acrylic acid) (PAAc) spacer arms are first introduced into the PLA surface via plasma post-irradiation grafting technique. Then, covalent coupling or physical adsorption of GlcN with/on the PAAc spacer is carried out. Factors affecting the grafting yield are controlled to produce a suitable spacer for bioimmobilization. X-ray photon spectroscopic (XPS) analyses confirm the immobilization of GlcN on the PLA surface. The XPS results reveal also that increasing the yield of grafted PAAc spacer on the PLA surface increases the amount of covalently immobilized GlcN, but actually inhibits the immobilization process using the physical adsorption method. Contact angle measurements and atomic force microscopy (AFM) show a substantial increase of surface energy and roughness of PLA surface, respectively, upon the multistep modification procedure. The cytocompatibility of the modified surfaces is assessed using a mouse embryonic fibroblast (MEF) cell line. Observation from the cell culture basically demonstrates the potential of GlcN immobilization in improving the cytocompatibility of the PLA surface. Moreover, the covalent immobilization of GlcN seems to produce more cytocompatible surfaces if compared with the physical adsorption method. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 3176-3188, 2017.

Polymeric pH-sensitive hydrogel nanoparticles (nanogels) of narrow size distributions were directly prepared by gamma radiation-induced polymerization of acrylic acid (AAc) in an aqueous solution of polyvinylpyrrolidone (PVP) as a template polymer. The driving force of PVP/PAAc nanoparticles formation was attributed to the complexation between PAAc (proton-donor) and PVP (proton-acceptor) through the hydrogen bonding interaction. In addition to the hydrogen bonding interaction between the components, the nanoparticles are further stabilized by covalent bonds as a result of the radiation-induced crosslinking process. Particle size and swellability of the prepared nanogels can be controlled by feed composition and concentration, PVP molecular weight as well as irradiation dose, temperature, and atmosphere. The prepared PVP/PAAc nanogel particles were characterized by dynamic light scattering (DLS), viscometry, transmission electron microscopy (TEM) and atomic force microscopy (AFM) techniques.

Polyvinyl alcohol (PVA) microgels were prepared using electron beam irradiation. To improve the PVA microgel functionality and gel fraction, chains of polyacrylic acid (PAA) were incorporated into PVA microgel by radiation grafting technique. The increase in the acrylic acid (AA) content as well as PVA Mwt is accompanied by a mutual increase in the gel fraction and a decrease in the swelling%. Immobilization of different TiO2 concentrations on the surface of the prepared PVA–AA microgel was carried out. The structural changes in the prepared PVA–AA microgel immobilized with TiO2/were investigated using FTIR, EDX and XRD. Photodegradation efficiency of TiO2/PVA–AA microgel against metnil yellow dyes was studied. TiO2/PVA–AA microgel activity increases with the increase of the amount of TiO2 and results in an increase in the rate of the photodegradation reaction. Easily recovery and reusability made TiO2/PVA/AA of great important in practice use as a photocatalytic degradation composite, for dye removal from wastewater.

Radiation is a very effective tool for controlling the degradation of natural occurring polymers like Na-alginate which may be used in agricultural purposes. One of the principle factors for reducing the cost is achieving the degradation at low irradiation doses. The addition of some additives such as potassium per-sulfate (KPS), ammonium per-sulfate (APS), or H 2 O 2 to Na-alginate polymers during irradiation process enhanced, accelerated, reduced the dose required for their degradation process and also improved the quality of the end use products. The highest degradation rate of Na-alginate was obtained when the APS was used. Molecular weight and structural changes of the degraded alginates were determined. The possible practical use of such degraded Na-alginate as a growth promoter for zea maize plant was investigated. The use of radiation degraded alginate not only increases the productivity of zea maize plant but also improve its quality. The results obtained showed that end product of irradiated Na-alginate may be benefited in agricultural purposes as growth promoter for some plants.

Grafting of vinyl acetate (VAc), 2-hydroxyethyl methacrylate (HEMA), and their binary monomer onto poly(tetraflouroethylene-perflourovinyl ether) (PFA) copolymer films was performed by means of gamma rays from 60Co using the direct method. The factors affecting the grafting yield such as type of solvent, inhibitor concentration, monomer and comonomer concentrations, comonomer composition, and irradiation dose were investigated. It was found that the magnitude of the enhancement depends on the VAc/HEMA ratio in the comonomer feed solution; the grafting yield was higher when VAc-rich comonomer feed solution is used. The TGA analysis indicated that the copolymerization grafting of VAc/HEMA binary monomers onto PFA matrix improves the thermal stability. The results obtained in this study suggest that PFA-g-p(VAc/HEMA) copolymers have the potential to be used as blood-contacting devices in a broad range of biomedical applications. © 2011 Wiley Periodicals, Inc. Adv Polym Techn 30:21–32, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.20204

Controlling the degradation of chitosan by gamma ray from a 60 Co source in the in presence of initiators such as ammonium per-sulfate and hydrogen peroxide, was investigated. The factors affecting the degradation process such as irradiation dose, type of initiator and its concentrations were studied. The efficiency of these methods was verified by viscometric and GPC analysis and the average molecular weight of degraded chitosan were determined. The irradiation degradation in the presence of chemical initiator was much more appropriate from economical point of view because it reduced the irradiation doses required for degradation. Characterization of degraded polymer by FT-IR spectroscopy, UV–vis spectroscopy, XRD, ESR and TGA analysis was investigated. The water-soluble chitosan separated from degraded chitosan prepared at different irradiation doses showed a strong effect on the growth of Faba bean plant and can be used in agriculture fields as a growth promoter.

A unique natural polymer based colon specific drug carrier was prepared from carboxymethyl cellulose (CMC) and acrylic acid (AAc) in aqueous solution employing γ‐radiation induced copolymerization and crosslinking. The effect of preparation conditions such as the natural polymer content and irradiation dose on gelation process was investigated. The swelling behavior of the prepared hydrogels was characterized by investigating the time and pH dependent swelling of the (CMC/AAc) hydrogels of different CMC content. The effects of the hydrogel composition and pH of the swelling medium on the swelling indices were estimated. The results show that the increment in the CMC content in the feed solution enhances the gelation process. The results also show the dependence of the swelling indices on both hydrogel composition and pH value of the swelling medium. To evaluate the ability of the prepared hydrogel to be used as a colon‐specific drug carrier, the release profile of theophylline was studied as a function of...

Polyacrylamide/sodium alginate (PAAm/Na-alginate) crosslinked copolymers were prepared by using electron beam irradiation. The gel content and the swelling behavior of the obtained copolymers were investigated. The thermal and morphological properties of the prepared copolymers were studied using thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The thermal stability of PAAm significantly changed when mixed with Na-alginate. The addition of PAAm/Na-alginate copolymer in small quantities to sandy soil increased its ability to retain water. The growth and other responses of the faba bean plant cultivated in a soil treated with PAAm and PAAm/Na-alginate copolymer were investigated. The growth of the bean plant cultivated in a soil containing PAAm/Na-alginate was better than that cultivated in soil treated with PAAm. The most significant difference between the PAAm and its alginate copolymer is that the latter partially undergoes radiolytic and enzymatic degradation to produce oligo-alginate, which acts as a plant growth promoter. The increase in faba bean plant performance by using PAAm/Na-alginate copolymer suggested its possible use in the agriculture field as a soil conditioner, providing the plant with water as well as oligo-alginate growth promoter. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3572–3580, 2006

Crosslinked poly(e-caprolactone) (PCL) was prepared by electron beam irradiation in the presence of the polyfunctional monomer A-TMPT. As the A-TMPT ratio and irradiation dose increase, the PCL gel fraction increases and consequently its heat resistant property significantly improves. The thermal parameters of crosslinked PCL such as the melting temperature (Tm), recrystallization temperature (Trc), and heat of recrystallization (ΔHrc), were slightly influenced. The surface morphology and structure of biodegraded crosslinked PCL were investigated by scanning electron microscope (SEM), differential scanning calorimetry (DSC) and thermo-gravimetric analyzer (TGA). The results showed that the erosion reaction temperature had a great effect on the morphology and structure of modified PCL and consequently influenced its degradation rate. The introduction of the crosslinking into PCL diminished its ability to biodegrade.

In order to rise the yield of prednisolone from hydrocortisone, thePseudomonas oleovoranscells were entrapped into radiation crosslinked poly(vinyl pyrrolidone)/poly(ethylene oxide)(PVP/PEO) hydrogel of different gel contents. The factors affecting the gel content and swelling behavior of the polymeric gel, such aspolymercomposition,polymerblend concentration, and irradiation doses, were investigated. The formation of gels having a good strength with the ability to retain a desirable amount of water in their three-dimensional network can be achieved by using PVP/PEO copolymer of composition(90:10)and concentration of 15% prepared at 20 kGy irradiation dose. At these conditions the prepared hydrogel is considered the most favorable one that gave the highest hydrocortisone bioconversion and prednisolone yield, 81% and 62.8%, respectively. The improvement of prednisolone yield was also achieved by increasing substrate concentration. Maximum hydrocortisone bioconversion (86.44) was obtained at 18 hours by using substrate concentration of 30 mg. Reusability of immobilizedPseudomonas oleovoransentrapped into PVP/PEO copolymer hydrogel was studied. The results indicated that the transformation capacity of hydrocortisone to prednisolone highly increased by the repeated use of copolymer for 4 times. This was accompanied by an increase in prednisolone yield to 89% and the bioconversion of hydrocortisone was 98.8%.

Pseudomonas fluorescens cells, which convert hydrocortisone to prednisolone, was entrapped in poly-hydroxy ethylmethacrylate (Poly-HEMA) which was prepared by radiation polymerization at low temperature. Using pure poly-HEMA without cross-linking monomer agents increases prednisolone yield to 43.9% compared with the yield produced using polymerized HEMA mixed with N , N ′-methylene-bis-acrylamide (36.9%) or 0.1 and 0.2 ml of divinely benzene (39.6 and 26.0%, respectively). Maximal prednisolone productivity (1.83 mg/l/h) was attained using 20 kGy γ-irradiation for polymerization of HEMA and this was accompanied by lowest productivity of the 20β-hydroxy-derivative. Prednisolone yield reached 59.8% on increasing the water content of HEMA before polymerization. Maximum prednisolone yield and productivity without formation of 20β-hydroxy-derivative (64.1 and 2.67 mg/l/h) were recorded using poly-HEMA polymer loaded with 24 h old Ps. fluorescens cells after a 24 h transformation period. The maximum bioconversion efficiency was obtained at a substrate concentration of 20 mg/100 ml medium. Poly-HEMA immobilized Ps. fluorescens cells can be repeatedly used about 12 cycles with gradual increase in the prednisolone yield (76.5–84.3%) by repeated use for 7 times.

Ionizing radiation and oxidizing agent like H2O2 were used to degrade chitosan (CS) and its derivatives; N-maleoylchitosan (NMCS), and N-phthaloylchitosan (NPhCS). The structure changes were detected using gel permeation chromatography (GPC). The results revealed that ionizing radiation degraded CS, MNCS, NPhCS and altered their molecular weights and antioxidant activity. The higher the irradiation dose, the lower the molecular weight and the higher antioxidant activity. The addition of irradiated CS and NMCS to minced chicken resulted in highly significant reduction in malondialdehyde (MDA) content (50 and 70%, respectively) if compared with the control. The irradiated NMCS toxicity study did not show strong proliferative effect at small concentrations or cytotoxic effects at higher concentrations. The obtained results suggested that CS and NMCS could be used as natural antioxidant for improving the oxidative deterioration of minced chicken during refrigerated storage.

This study aimed to investigate the ability of dopamine (DA)-loaded polyvinylpyrrolidone-poly(acrylic acid) (PVP/PAAc) nanogel [synthesized by gamma (γ) radiation-induced template polymerization] [Nano-DA] to deliver DA across the blood brain barrier, and to evaluate the efficacy and safety of the acute and subchronic administration of Nano-DA in modulating motor activity and/or the biochemical changes in rat brain; induced by different models of Parkinsonism. In this respect, (PVP/PAAc) nanogel was synthesized by gamma radiation-induced polymerization of acrylic acid (AAc) in an aqueous solution of PVP as a template polymer, and then, it was used as a nano-drug carrier for DA. The PVP/PAAc and (PVP/PAAc loaded-DA nanogel particles were characterized by dynamic light scattering, infrared spectroscopy, and field emission-scanning electron microscopy. The loaded gel was administered in different doses and dosing regimens to Parkinsonian rats, and the catalepsy score and striatal DA levels were assessed. Then, the potential disease-modifying activity of this form of DA was investigated, through the assessment of the improvement in mitochondrial function, following the subchronic administration of Nano-DA to Parkinsonian rats. Significant disease-modifying effects were observed upon the administration of Nano-DA; in addition to normalization in their motor activity.

The aim of this study was to improve the stability and bioavailability of pilocarpine in order to maintain an adequate concentration of the pilocarpine at the site of action for prolonged period of time. Thus, pH-sensitive polyvinylpyrrolidone-poly(acrylic acid) (PVP/PAAc) nanogels prepared by γ radiation-induced polymerization of acrylic acid (AAc) in an aqueous solution of polyvinylpyrrolidone (PVP) as a template polymer were used to encapsulate pilocarpine. Factors affecting size and encapsulation efficiency were optimized to obtain nanogel suitable for entrapping drug efficiently. The PVP/PAAc nanogel particles were characterized by dynamic light scattering (DLS), zeta potential, Fourier transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM), and their size can be controlled by the feed composition and concentration as well as the irradiation dose. Pilocarpine was loaded into the nanogel particles through electrostatic interactions where the AAc-rich nanogels exhibited the highest loading efficiency. The transmittance, mucoadhesion, and rheological characteristics of the nanogel particles were studied to evaluate their ocular applicability. The in vitro release study conducted in simulated tear fluid showed a relatively long sustained release of pilocarpine from the prepared PVP/PAAc nanogel particles if compared with pilocarpine in solution.

Modification of chitosan (CS) to N-maleoylchitosan (NMCS), N-phthaloylchitosan (NPhCS) and sulfonated-chitosan (SCS) was done using maleic anhydride, phthalic anhydride and chlorosulfonic acid, respectively followed by exposing them to γ-rays at different doses. The molecular weights and structural changes of irradiated chitosan derivatives were determined by GPC, FT-IR and UV-vis spectrophotometer. The molecular weights decreased with increasing irradiation dose. Results revealed that the main polysaccharide structure remained after irradiation. To investigate the enhancement of antioxidant activity of chitosan and its derivatives of different molecular weights, radical mediated lipid peroxidation inhibition, scavenging effect of DPPH radicals, reducing power and ferrous ion chelating activity assays were used. Chitosan derivatives with different molecular weights exhibit antioxidant activity. The lower the molecular weights of chitosan and its derivatives, the higher the antioxidant activity. NMCS possessed high scavenging effect on DPPH radicals compared with NPhCS, SCS and ascorbic acid. The irradiated chitosan and its derivatives could be used as natural antioxidants.