Radiation Synthesis of Selenium Nanoparticles Capped with ß-Glucan and Its Immunostimulant Activity in Cytoxan-Induced Immunosuppressed Mice.

Selenium nanoparticles (SeNPs) with diameters from 64.8 to 110.1 nm were successfully synthesized by γ-irradiation of solutions containing Se4+ and water-soluble yeast ß-glucan. The size and size distribution of SeNPs were analyzed by dynamic light scattering (DLS). Analytical X-ray diffraction (XRD) pattern results confirmed the crystal structure of the Se nanoparticles and Fourier transform infrared (FTIR) spectroscopy revealed that ß-glucan could interact with SeNPs through steric (Se…O) linkages leading to a homogeneous and translucent solution state for 60 days without any precipitates. In vivo tests in cytoxan-induced immunosuppressed mice revealed that the daily supplementation of SeNPs/ß-glucan at concentrations of 6 mg per kg body weight of tested mice significantly stimulated the generation of cellular immune factors (white blood cells, neutrophil, lymphocyte, B cells, CD4+ cells, CD34+ cells and natural killer cells) and humoral immune indexes (IgM, IgG, TNF-α, IFN-γ and IL-2) in peripheral blood, bone marrow and spleen of the immunosuppressed mice. The obtained results indicated that radiation-synthesized SeNPs/ß-glucan may be a candidate for further evaluation as an agent for the prevention of immunosuppression in chemotherapy.

Radiation Degradation of ß-Glucan with a Potential for Reduction of Lipids and Glucose in the Blood of Mice.

: Water-soluble and low molecular weight (Mw) ß-glucans were successfully prepared by γ-irradiation of water-insoluble yeast ß-glucans. The radiation dose used for the degradation of yeast ß-glucan was remarkably reduced by increasing the pH of the sample or combining with hydrogen peroxide treatment. Radiation-degraded ß-glucans with molecular weights in the range of 11-48 kDa reduced the total cholesterol, triglyceride, low density lipoprotein (LDL) cholesterol, and glucose levels in the blood of administered mice. The decreasing levels of both lipid and glucose indexes in the blood of tested mice strongly depended on the molecular weight of the ß-glucan, and the radiation-degraded ß-glucan with a molecular weight of about 25 kDa was found to be the most effective for the reduction of blood lipid and glucose levels. Particularly, the oral administration of 25 kDa ß-glucan, with a daily dose of about 2 mg per head, reduced the total cholesterol, triglyceride, LDL-cholesterol, and glucose levels in the blood of tested mice to about 47.4%, 48.5%, 45.7%, and 47.2%, respectively. The effects on the reduction of blood lipid and glucose levels were also found to be stable after 20 days of stopping administration. These results indicate that the degraded ß-glucan with a molecular weight of about 25 kDa prepared by γ-ray irradiation is a very promising ingredient that can be used in nutraceutical food for therapeutics of diabetic and dyslipidemia.

Radiation degradation of (1→3)-ß-d-glucan from yeast with a potential application as a plant growth promoter.

The (1→3)-ß-d-glucan extracted from the yeast cell wall was irradiated by γ-rays from a Co-60 source at dose range of 100-300kGy in a swelling condition of 10, 15 and 20% for degradation. The water-soluble contents of irradiated samples obtained by 10% (1→3)-ß-d-glucan mixture increased from 25.89 to 66.71% by the increasing of irradiation doses from 100 to 300kGy. While the molecular weight of the water-soluble (1→3)-ß-d-glucan was found to be decreased from 48.13 to 10.77kDa. In the UV-spectra of irradiated water-soluble (1→3)-ß-d-glucan, a new peak appeared at 265nm with the intensity increased by the increase of the dose. The IR spectra of irradiated (1→3)-ß-d-glucan were recognized by a decrease of the peak intensity at 1156cm(-1) indicated to COC glycosidic linkages with the increasing of irradiation dose. In addition, radiation degraded (1→3)-ß-d-glucan with Mw about 18kDa prepared at the dose of 250kGy displayed a strongly promotion effect on the growth of mustard green and the optimum concentration of the degraded (1→3)-ß-d-glucan was found to be about 75mgl(-1). Thus, the degraded (1→3)-ß-d-glucan prepared by radiation technique displayed as a promising, safety and high effective plant growth promoter for agriculture application.

Study on antibacterial activity of silver nanoparticles synthesized by gamma irradiation method using different stabilizers.

Colloidal solutions of silver nanoparticles (AgNPs) were synthesized by gamma Co-60 irradiation using different stabilizers, namely polyvinyl pyrrolidone (PVP), polyvinyl alcohol (PVA), alginate, and sericin. The particle size measured from TEM images was 4.3, 6.1, 7.6, and 10.2 nm for AgNPs/PVP, AgNPs/PVA, AgNPs/alginate, and AgNPs/sericin, respectively. The influence of different stabilizers on the antibacterial activity of AgNPs was investigated. Results showed that AgNPs/alginate exhibited the highest antibacterial activity against Escherichia coli (E. coli) among the as-synthesized AgNPs. Handwash solution has been prepared using Na lauryl sulfate as surfactant, hydroxyethyl cellulose as binder, and 15 mg/L of AgNPs/alginate as antimicrobial agent. The obtained results on the antibacterial test of handwash for the dilution to 3 mg AgNPs/L showed that the antibacterial efficiency against E. coli was of 74.6%, 89.8%, and 99.0% for the contacted time of 1, 3, and 5 min, respectively. Thus, due to the biocompatibility of alginate extracted from seaweed and highly antimicrobial activity of AgNPs synthesized by gamma Co-60 irradiation, AgNPs/alginate is promising to use as an antimicrobial agent in biomedicine, cosmetic, and in other fields.

Preparation of oligoalginate plant growth promoter by γ irradiation of alginate solution containing hydrogen peroxide.

Degraded alginate compounds with molecular weights of 7-26, 40-77, or 11-26 kDa were obtained by γ irradiation, hydrogen peroxide (5% H(2)O(2)) treatment, or a combination treatment involving ionizing radiation and H(2)O(2), respectively. The 14 kDa oligoalginate, prepared by the combined method, promoted the growth of mustard greens and lettuce at an optimal concentration of 75 mg/L. The growth promotion effects of the oligoalginate prepared by γ irradiation in the presence of H(2)O(2) were statistically equivalent to those of the oligoalginate prepared by γ irradiation only. The combination of γ irradiation and H(2)O(2) reduced the required irradiation dosage by a factor of 9 relative to the oligoalginate produced by γ irradiation only. The combination treatment (γ irradiation/H(2)O(2)) may be carried out on a large scale at low cost to produce oligoalginate for use as a plant growth promoter in agricultural industries.