ABSTRACT
With the advent of Nanotechnology, the use of nanomaterials in consumer products is increasing on a daily basis, due to which a deep understanding and proper investigation regarding their safety and risk assessment should be a major priority. To date, there is no investigation regarding the microrheological properties of nanomaterials (NMs) in biological media. In our study, we utilized in silico models to select the suitable NMs based on their physicochemical properties such as solubility and lipophilicity. Then, we established a new method based on dynamic light scattering (DLS) microrheology to get the mean square displacement (MSD) and viscoelastic property of two model NMs that are dendrimers and cerium dioxide nanoparticles in Dulbecco's Modified Eagle Medium (DMEM) complete media at three different concentrations for both NMs. Subsequently, we established the cytotoxicological profiling using water-soluble tetrazolium salt-1 (WST-1) and a reactive oxygen species (ROS) assay. To take one step forward, we further looked into the tight junction properties of the cells using immunostaining with Zonula occluden-1 (ZO-1) antibodies and found that the tight junction function or transepithelial resistance (TEER) was affected in response to the microrheology and cytotoxicity. The quantitative polymerase chain reaction (q-PCR) results in the gene expression of ZO-1 after the 24 h treatment with NPs further validates the findings of immunostaining results. This new method that we established will be a reference point for other NM studies which are used in our day-to-day consumer products.
ABSTRACT
An improved active packaging system was developed for fresh fruits using silver nanoparticles (AgNPs) coupled with calcium alginate (Ca-ALG). For the synthesis of AgNPs aqueous, ethanol and methanol extracts of Artemisia scoparia (AS) were used. These AgNP's were characterized using UV-Vis, SEM, EDS, AFM, FTIR and gel electrophoresis. Ethanol extract of AS (ASE) produced AgNPs with smallest size in comparison to aqueous AS (ASA) and methanol extract of AS (ASM). AgNPs synthesized from ASE had a size range of 12.0-23.3â¯nm and were tested on Human Corneal Epithelial Cells to evaluate their cytotoxicity. At 0.05â¯ng/mL of AgNP's concentration, no toxic effects were observed on the evaluated cell line. Therefore, 0.05â¯ng/mL of AgNPs mixed with edible coating of Ca-ALG were applied on strawberries and loquats as active coating to increase their shelf life. Significant improvement was observed in the quality parameters of strawberries and loquats such as microbial analysis, acidity loss, soluble solid content loss, weight loss and quality decay. Ca-ALG coating incorporated with AgNPs enhanced the shelf life of strawberries and loquats in comparison to no treatment and simple Ca-ALG coatings. This study provides an insight to food industry to extend the shelf life of fresh fruits using AgNP's formulated coatings.
