Biosafety risk assessment of nanoparticles: Evidence from food case studies.

Nanotechnology provides a wide range of benefits in the food industry in improving food tastes, textures, sensations, quality, shelf life, and food safety. Recently, potential adverse effects such as toxicity and safety concerns have been associated with the increasing use of engineered nanoparticles in food industry. Additionally, very limited information is known concerning the behavior, properties and effects of food nano-materials in the gastrointestinal tract. There is explores the current advances and provides insights of the potential risks of nanoparticles in the food industry. Specifically, characteristics of food nanoparticles and their absorption in the gastrointestinal tract, the effects of food nanoparticles against the gastrointestinal microflora, and the potential toxicity mechanisms in different organs and body systems are discussed. This review would provide references for further investigation of nano-materials toxicity effect in foods and their molecular mechanisms. It will help to develop safer foods and expand nano-materials applications in safe manner.

Preparation of Nano-Silver-Containing Polyethylene Composite Film and Ag Ion Migration into Food-Simulants.

Nano-composite films were developed between silver nanoparticles (Ag NPs) and a low-density polyethylene (LDPE) using master batches by melt extruding and melt compounding. The Ag/PE composite film showed decreased gas permeability, moisture permeability coefficient, the tear strength, the longitudinal and transverse elongation to that of commercial LDPE. Although stiffness increased at high Ag (40 ppm) concentration, but the longitudinal and transverse tensile strength enhance comparing with commercial PE. Light transmittance and haze were comparable. Both Nano-silver and composite films are effective against Escherichia coli (E. coli). Antibacterial activity of nano-silver for E. coli was determined by diameter of the inhibition zone and the minimum inhibitory concentration of nano-silver is detected by tube double dilution method reaching 15.63 ppm. The composite films are effective inhibition of E. coli at concentrations of 40 ppm Ag nanoparticles. Moreover, Nano-silver migration occurs in composite film. One-side migration was conducted to detect under three food simulants (3% acetic acid, 50% ethanol and distilled water) at three degree of temperature (25 °C, 40 °C and 70 °C) on different period of time (2, 4, 6, 8, 10 and 12 hours). These results indicated that the highest migration amount was obtained with 3% acetic acid following distilled water and finally 50% ethanol under same conditions. The migration level is dependent upon time and temperature and high migration time and temperature can enhance migration level. These findings demonstrate that nano-silver-containing polyethylene composite film may have a great potential for developing antibacterial and acid food packaging system.

[Testicular mixed nonseminomatous germ cell cancer: a case report and review of the literature].

OBJECTIVE: Testicular mixed nonseminomatous germ cell cancer (TMNGCC) is rarely reported. This study aimed to explore the clinical symptoms, pathological characteristics and treatment methods of TMNGCC. METHODS: We analyzed the clinical data of 1 case of TMNGCC, observed its pathological characteristics under the light microscope by histology, cytochemistry, immunohistochemistry and immune marking, and investigated the clinical features of such tumors by reviewing the relevant literature. RESULTS: The patient presented with a chief complaint of painless testicular swelling for 3 years. Histopathological examinations revealed a tumor of papillary, fissural or adenoid structure, with large polygonal or columnar cells with one or more irregular vesicular nuclei, the nuclear membrane clear, the cytoplasm eosinophilic or basophilic, and the interstitium infiltrated by a few lymphocytes. Here are the immunohistochemical results: CD117 -, CK8-18 + +, CD30 + +, CK + + +, vimentin -, PLAP +/-, P53 +, AFP + and EMA + +. The tumor was pathologically diagnosed as teratogenic embryonic testicular cancer, and treated by radical surgery, followed by adjuvant chemotherapy according to the treatment of TMNGCC. One-year follow-up found the patient to be alive. CONCLUSION: TMNGCC is a rare malignant tumor, mostly with unobvious clinical symptoms. Its diagnosis primarily depends on physical examination, ultrasonography, CT, and measurement of serum tumor markers; its confirmation necessitates pathological examination, and its first-choice treatment is surgical resection.