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Showing 8 results for Polyethylene Glycol


Volume 0, Issue 0 (1-2024)
Abstract

Controlling insect pests through nano-based formulation of chemicals is one of the newly applied methods in IPM programs; however, the probable side impacts of nano-pesticides on non-target organisms need to be evaluated. In this study, deltamethrin and matrine were encapsulated with polyethylene glycol (PEG) and chitosan (Cs), respectively, and their toxicity were investigated against Habrabracon hebetor Say using the contact method. According to the scanning electron microscopy (SEM), spherical nanoparticles for both formulations were observed. The average hydrodynamic nanoparticle diameters for deltamethrin and matrine were 65 and 70.5 nm. The LC50 values were 254.48, 334.90, 760.31 and 1021 mg L-1 in PEG-encapsulated deltamethrin, commercial deltamethrin, Cs-encapsulated matrine, and commercial matrine, respectively. Exposing to the LC30 of the commercial and nano-encapsulated deltamethrin significantly prolonged the total pre-adult period. The adults of H. hebetor in PEG-encapsulated deltamethrin treatment had the lowest longevity compared to other treatments and control. Furthermore, the sublethal exposure to the PEG-based nanoformulation of deltamethrin and commercial deltamethrin resulted in a significant reduction of the intrinsic rate of natural increase (rm) (0.159 and 0.168 day-1, respectively). Same trend was observed for the gross reproductive rate (GRR), net reproductive rate (R0), and finite rate of increase (λ) of the parsitoid. Our findings indicate that the negative side effects of commercial and nano-based formulations of deltamethrin on H. hebetor should be considered in IPM programs.
 

Volume 7, Issue 3 (7-2019)
Abstract

Aims: Germination stage is one of the most sensitive stages to drought stresses and if the plant is able to tolerate stresses in this stage, it can pass the later growth stages. Priming could improve germination of seeds under stress.
Materials and Methods: Experiment was carried out using a randomized complete block design. 25 seeds were placed in petri dish under drought stress with polyethylene glycol 6000 in three levels of 0, -6 and -12 bar. After 14 days, it was found that the germination percent in these seeds was low (>40%). Then nano priming was used to improve seed germination attributes. Treatments were; control, silver nanoparticles with the concentrations of 25, 50 and 75%.
Findings: Data analysis of variance indicated that influence of nano priming, drought stress, and their interaction was significant on root and shoot length, wet and dry weight, vigor index, allometric coefficient and mean germination time (p≤0.01). Results showed that PEG stress had a negative effect on seeds germination. And an increase of silver nanoparticles concentration improves F. ovina seed germination and seedling traits. The maximum of GP (86%), SG (6N/D), Vi (5), AC (6) and MGT (7.08d) were recorded for seeds nano primed in the stress of 0 level.
Conclusion: Nano-priming is an impressive technique to the betterment of seedlings germination and growth of F. ovina. In the most studied indices, nano-priming 75% had the greatest influence. Before planting to restore of rangelands, to promote the establishment and growth of planted F. ovina it is recommended to prime seeds with nano-silver particles.


Volume 8, Issue 1 (3-2024)
Abstract

Research subject: This study aims to improve the biocompatibility, bioactivity, and mechanical properties of gelatin-based composite scaffolds by coating them with polyethylene glycol (PEG) doped with bioactive glasses (BGs) containing zinc and magnesium.
Research approach: A response surface methodology (RSM) was used to model and evaluate the effects of two independent variables: the PEG/Gel weight ratio (X1) and the BG weight percentage (X2). The responses investigated included ultimate strength, Young's modulus, elongation at break, swelling percentage, erosion percentage, and moisture absorption percentage.
Main results: Optimal conditions were determined to obtain scaffolds with suitable mechanical strength, biocompatibility and degradability. Analysis of variance (ANOVA) was used to obtain the best model describing the influence of each independent variable on the responses. The optimal scaffold formulation was selected based on software-defined parameters. The FTIR spectrum was used to analyze the functional groups present on the surface of the samples. The FTIR spectrum of the synthesized BGs showed a broad vibrational band in the range of 900 to 1100 cm-1, which is attributed to the asymmetric Si-O-Si stretching band. The FTIR spectrum of the PEG/Gel/BG composite confirmed the presence of BG in the scaffolds and the interaction between the polymer matrix and BG. Increasing the amount of BG relative to the polymer scaffold led to a decrease in pore size and consequently, a decrease in the scaffold's swelling percentage. The effect of varying the BG weight percentage on tensile strength was greater than that of the PEG/Gel weight ratio. The tensile strength increased significantly due to the good interaction between the polymer scaffold and BG, as well as the uniform dispersion of BG within the polymer matrix. SEM images indicated that cells penetrated well into the scaffolds and formed a suitable three-dimensional cellular network. Cytotoxicity, cell attachment and proliferation, and osteogenic differentiation were evaluated using the MTT test and by culturing MG-63 cells on the scaffold. Cell viability showed no significant difference between the tested and control samples.
 
Sheyda Jahazi, Hashem Yaghoubi, Hossein Akbari,
Volume 11, Issue 2 (6-2020)
Abstract

Iron oxide nanoparticles are one of the nano carriers that are suitable for novel drug delivery systems due to low toxicity, biocompatibility, loading capacity and controlled drug delivery to cancer cells. The purpose of this study is the synthesis of coated iron oxide nanoparticles for delivery of Doxorubicin (DOX) and its effects on cancer cells.
In this study, Fe3O4 magnetic nanoparticles were synthesized by Polyol method, and then doxorubicin was loaded onto PEGylated iron oxide nanoparticles. FT-IR was used to ensure PEG binding to nanoparticles and loading the drug onto nanoshell. Comparison of the mean size and the crystalline structure of nanoparticles were performed by TEM and X-ray diffraction pattern. Then, the effect of cytotoxicity was evaluated on AGS and MCF-7 cancer cells by MTT assay.
According to FT-IR results, the presence of O-H and C-H bands at 2927 cm-1 and 3392 cm-1 peaks correlated with PEG binding to nanoparticles. XRD pattern showed the cubic spinel structure of trapped magnetite nanoparticles carrying medium with a mean size of 14 nm. 21.67% of Doxorubicin was loaded into Fe3O4-PEG nanoparticles, which the highest drug release recorded during the first 24 hours. MTT assay at 24, 48 and 72 h treatments showed that with increasing concentrations of doxorubicin loaded Fe3O4-PEG nanoparticles from 0 to 50 μm, the cytotoxic effects of the drug gradually increase.
This study showed that PEGylation of iron oxide nanoparticles and using them in drug delivery process to increase the effect of Doxorubicin on AGS and MCF-7 cancer cells

Volume 13, Issue 7 (12-2011)
Abstract

Six rumen fistulated adult sheep were used to assess the effect of tannins (hydrolysable tannin; HTs) in oak leaves (Quercus Libani Oliv.) on ruminal fermentation parameters in a change-over design experiment for 28 days in 3 periods. Polyethylene glycol (PEG) was used to deactivate the tannins. The three dietary treatments were control (alfalfa hay, barley grain, wheat bran, wheat straw); OL (oak leave, barley grain, wheat bran and urea) and OL+ 80 g PEG. Animals were held in individual pens and metabolism cages. They were adapted to experimental conditions for 21 days before the commencement of the measurement periods. In each period, the digestibilities of dry matter (DMD), organic matter (OMD), NDF (NDFD), crude protein (CPD) and ruminal parameters (pH, ammonia, bacteria and protozoa population), and microbial protein synthesis were measured using urinary purine derivatives in sheep. The DMD, OMD, NDFD and CPD were decreased by oak leaves and the addition of PEG improved CPD (P<0.05). The ruminal pH values for all diets were within the normal range. Ruminal ammonia was similar among the treatments (p>0.05). Hydrolysable tannins in OL diets decreased (P<0.05) urinary allantoin in comparison to the control diet. Addition of PEG increased (P<0.05) allantoin. The uric acid, xanthine and hypoxanthine excretion in urine were not affected by the diet. Feeding OL diet decreased the microbial N in sheep, whereas addition of PEG improved it. The total protozoa count in sheep offered OL diet declined in comparison to those fed the control diet; however, addition of PEG had no effect on it. Sheep fed OL diet had significantly less cellulolytic and proteolytic bacteria than those fed the control diet (P<0.05), but improved (P< 0.05) with feeding of PEG along with OL. It was concluded that diets containing Q. Libani leaves had lower ruminal fermentability than diet containing alfalfa and that supplementation of PEG in OL diet improved the fermentability.

Volume 15, Issue 3 (10-2012)
Abstract

Objective: Due to recent advances in nanotechnology it is now possible to accumulate high atomic-number nanomaterial such as gold nanoparticles (GNPs) in cancerous cells and take advantage of their absorbed dose enhancement property as radiosensitizing agents. This study aimed to investigate the absorbed dose enhancement factor due to the presence of PEGylated GNPs under the irradiation of an MCF-7 cancerous cell line using orthovoltage X-ray beams. Methods: We synthesized GNPs with an average diameter of 47 nm and joined them to polyethylene glycol. A total of 50 μg/mL of the pegylated GNPs were incubated with MCF-7 cells for 1, 2, 6, 12, and 24 hours, after which we compared their cytotoxicities. Then, PEGylated GNPs (50μg/mL) were incubated with MCF-7 cells for 12 and 24 hours and their radiosensitizing effect during 2Gy delivery of 120, 180 and 200 kVp X-ray beams were compared by the MTT assay. Results: Cytotoxicity studies showed no significant effect of GNPs on cell viability. Significant differences in cell survival were observed between the groups irradiated with and without GNPs, which lead to an average absorbed dose enhancement factor of 1.22±0.06. According to the results, there was no radiosensitization difference due to the usage of 120, 180 and 200 kVp X-ray beams. However increased incubation time increased the dose enhancement factor. Conclusion: By using PEGylated GNPs we can decrease the prescribed X-ray dose, yet maintain the same level of cancerous cell killing.

Volume 17, Issue 5 (9-2015)
Abstract

Pigeonpea (Cajanus cajan (L) Millsp.) is a drought tolerant legume widely grown in the arid and semi-arid tropics of the world which possesses a deep and extensive root system that succors a number of important physiological and metabolic functions to cope with drought. Application of available functional genomics approaches to improve productivity under water deficit requires a better understanding of the mechanisms involved during pigeonpea’s response to water deficit stress. In order to identify the genes associated with water deficit in pigeonpea, Suppression Subtractive Hybridization cDNA library was constructed from polyethylene glycol-induced water deficit young root tissues from pigeonpea and 157 high quality ESTs were generated by sequencing of 300 random clones which resulted in 95 unigenes comprising 37 contigs and 58 singlets. The cluster analysis of ESTs revealed that the majority of the genes had significant similarity with known proteins available in the databases along with unique and hypothetical/uncharacterized proteins. These differential ESTs were characterized and genes relevant to the specific physiological processes were identified. Northern blot analysis revealed the up regulation of ornithine aminotransferase, cyclophilin, DREB and peroxidase. The differentially expressed sequences are conceived to serve as a potential source of stress inducible genes of the water deficit transcriptome and hence may provide useful information to understand the molecular mechanism of water deficit management in legumes. 

Volume 18, Issue 2 (6-2015)
Abstract

Objective: The host immune response against minor donor blood groups may be considered a significant problem in certain groups of patients that undergo transfusions such as those who require repeat transfusions (thalassemia).  A proposed solution is to coat the surface antigens on red blood cells (RBCs) by covalent binding of methoxy polyethylene glycol (mPEG). This study aims to determine the storage time of PEGylated cells before injection and its effective time during in vivo conditions. Methods: We used mPEG activated by succinimidyl valerate (SVA) to PEGlayte the cells. The stability of the created coating during in vitro conditions was investigated by three methods: counting the numbers of free cells, flow cytometry and qualitative investigation. The appropriate concentration of mPEG for rabbit RBC PEGylation was determined by electron microscopy.  The effective time of PEGylated rabbit RBCs was determined with flow cytometric analysis after the injection. In addition, we investigated the serum biochemical properties at 24 hours after the injection. Results: The appropriate concentration of 15 mg/mL for rabbit RBC PEGylation was determined. At 48 hours after injection, 83% of the cells that were alive in the host circulatory system kept their polymeric coating. Conclusion: We determined that 18 days was an appropriate storage time for PEGylated RBCs under in vitro conditions. The effective time of 14 days was determined for PEGylated RBCs by tracking the cells in vivo. An investigation of the serum biochemical properties of rabbits at 24 hours after the injection showed that the RBC coating significantly inhibited stimulation of the host immune system and cell destruction.

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