Modares Journal of Biotechnology

Abstract The countries’ social and economic conditions have been threatened by corona epidemic and a large number of people’s death in the world. SARS-CoV-2 virus, a form of corona virus family, is responsible for corona disease and its spread in the present century. The study of the receptor binding region (RBD) in the spike protein is very important for scientists because the new corona virus uses its surface spike protein for binding to the ACE2 surface protein and entering its genetic material to the host cells. By this protein and its receptor binding region inhibition, the prevention of virus entrance to the cell is possible. The virus’s genes can be multiplied by cloning and its protein can be purified. The usage of antiviral peptides as the most practical methods and binding inhibitory peptides of RBD to the ACE2 receptor for SARS-CoV-2 treatment, are of great interest to scientists. In the present research, RBD cloning in PET28a expression vector, RBD protein expression and GFP/RBD fusion protein were performed in prokaryotic host. Due to this protein’s insolubility in the prokaryotic host, column refolding was performed with urea gradient with a nickel-agarose column and the synthesized protein was confirmed through western blot technique. Three nominated peptides from articles used to compare their binding to RBD using bioinformatics and their tendency to bind to each other was investigated by molecular docking. The mentioned peptides can be used in this virus infection treatment due to their binding potential to RBD, if their interaction is proven.

Abstract The aim of present research is development of a simple green approach to produce Ag/AgCl nanocomposites using bacterial strains Bacillus haynesii and Bacillus halotorans, nominated at PN14F and B3, respectively, via an extracellular process. The bacterial strains PN14F and B3 were isolated from the soil and wastewater samples, using dilution and direct cultivation method. The Ag/AgCl nanocomposites were synthesized from the reaction of silver(I) nitrate solution and supernatant under completely sterile conditions in the presence of light. Moreover, a series of controlled experiments were provided to optimize some reaction conditions such as substrate concentration, PH, substrate volume, bacterial volume, the presence of glucose as an electron donor and silver(I) nitrate as inducer. The products were characterized using various techniques such as UV-Vis, XRD, FT-IR, FE-SEM and EDX. The resulting bionanocomposites (Ag1 and Ag2), with an average particle size of 30 and 22.3 nm, were efficient heterogeneous catalysts for reducing para-nitrophenol to para-aminophenl. Further, it was demonstrated their activity as the antibacterial properties against gram positive and negative bacteria. The results showed that the Ag2 sample with reducing time of 15 min is a more efficient catalyst than the Ag1 nanocomposite, which can be attributed to the smaller size of the Ag2 nanoparticles.

Abstract Aspergillus has many species that are important in medicine, agriculture, and various industries. The genus has 446 identified species, which are difficult to distinguish from each other with the use of morphological characteristics. Xylan 1,4-beta-xylosidase is an enzyme that catalyzes the hydrolysis process of xylose in xylooligosaccharides and is produced by different species of Aspergillus. This research was conducted with the aim of a bioinformatics study of the gene region related to this enzyme and to evaluate its similarities and differences in some Aspergillus species. The results showed that this gene region, due to the presence of conserved motifs, was able to distinguish some species studied in this research.

Abstract Curcumin, a potent antioxidant extracted from the turmeric plant, is known for its ability to suppress reactive oxygen species (ROS) through activation of antioxidant response elements. However, its clinical utility is limited by poor solubility and rapid elimination. In this study, we aimed to enhance the solubility and bioavailability of curcumin by encapsulating it in fifth-generation polyamidoamine dendrimer nanoparticles. UV-Vis and fluorescence spectroscopy confirmed successful encapsulation, with an average nanoparticle size of 275 nm and a positive surface charge of 8 mV. The nanocarrier exhibited a loading capacity of approximately curcumin6 mol per dendrimer 1mol and achieved complete drug release within 72 hours. Cellular uptake assays using a live/dead assay revealed superior uptake of the nanocarrier compared to free curcumin, leading to a significant reduction in cellular ROS levels and apoptosis. Furthermore, in a model of induced oxidative stress using H2O2, curcumin-loaded dendrimer nanoparticles significantly reduced cellular ROS levels compared to free curcumin. These findings highlight the potential of this nanocarrier as an effective and intelligent system for delivering water-insoluble drugs, offering a promising approach for improving the therapeutic efficacy of curcumin.

Abstract New technologies in determining the gender of eggs will greatly help to end the extermination of male chickens, which will save a lot in the poultry industry. These technologies are so valuable and important that many companies and research centers are willing to make large investments to progress in this field. Today, two invasive and non-invasive methods are used to determine the gender of the egg. Invasive diagnostic methods often lead to a decrease in the viability of samples, while non-invasive methods with high accuracy and viability of samples have created a great development capability among researchers. In other words, invasive diagnostic methods determine the gender of the embryos inside the egg with a high percentage, but it can endanger the continuation of the hatching process and jeopardize food safety. However, the use of non-invasive methods in line with industrial use has priority due to the fact that there is no danger to the chick embryo in the process of sex determination. In this review study, while examining the importance of gender determination during hatching for the poultry industry, an attempt has been made to examine and compare all the new technologies used to determine gender in the egg-laying and hatching stages and compare its advantages and disadvantages.

Abstract Alpha-synuclein protein (α-syn) is the main factor known in Parkinson's disease. The expression of this protein has challenges. One of these challenges is the presence of protein in bacterial pellet. Studies have shown that the expression of proteins with tags such as small ubiquitin-like modifier (SUMO) increases the expression in the soluble phase, therefore the expression of α-syn with this sequence was investigated to increase the protein in the soluble phase. It has also been shown in studies that SUMOylation has an inhibitory effect on fibrillation, also in this study the effect of the SUMO on alpha-synuclein fibrillation was investigated. The α-syn gene was cloned with SUMO-tag. Nickel sepharose column was used to purify the protein, and dialysis was performed and fibrillation was checked by fluorescence emission of Thioflavin for 72 hours and was observed that the protein with SUMO sequence has a higher expression level, and 95% of the protein is in the soluble phase. On the other hand, it was shown that the SUMO sequence has an inhibitory effect on the process of amyloid fibril formation. The results obtained from previous studies showed that the binding of the SUMO sequence increases the expression and solubility of recombinant proteins. This study revealed that the presence of this sequence contributed to the protein expression level and the protein's presence in the solution phase. On the other hand, observations showed that this sequence has anti-fibrillation properties for proteins with amyloid properties, and in this study showed that SUMO prevents α-syn aggregation.

Abstract Iron oxide nanocomposites with lanthanides, due to their unique magnetic properties and biocompatibility, are recognized as attractive agents for the detection and treatment of cancerous tumors. Therefore, understanding the interaction of these nanocomposites with biological systems is important for their efficient design. In this study, samarium-doped magnetite iron oxide nanocomposite was synthesized chemically based on polyethylene glycol and triethanolamine. The nanocomposite w::::::::as char::::::::acterized using XRD, SEM, EDX, and DLS techniques. The crystal size of the nanocomposite was calculated to be approximately 12 nanometers using XRD. SEM image showed the synthetic nanocomposite as an agglomeration of fine particles with a spherical morphology. Subsequently, by incubating the nanocomposite in human blood plasma, the formation of a protein complex called corona protein on the surface of nanoparticles when exposed to biological systems was investigated and confirmed by gel electrophoresis. Cellular uptake results in the interaction of nanoparticles with cells showed that incubating the nanocomposite in human blood plasma led to a decrease in nanoparticle uptake in MDA-MB231 cancer cells and an increase in uptake in RAW 264.7 macrophages, indicating the binding of blood opsonin proteins on the nanoparticle surface. Furthermore, the results indicated that the formation of corona protein had no significant effect on the cellular toxicity of nanoparticles on MDA-MB231 cells at different nanoparticle concentrations up to 200 micrograms per milliliter, and no significant toxicity was reported.

Abstract Magnetic nanoparticles (MNPs) have emerged as contrast agents in magnetic resonance imaging (MRI) and metal-organic frameworks (MOFs) due to their high porosity and adjustable structure, serving as drug carriers and new contrast agents in biomedicine. Designing efficient nanoplatforms that leverage the combined properties of both MNPs and MOFs is of great importance.
In this study, we introduce a simple in-situ synthesis method for a mesopore core-shell nanocomposite structure of MOF@Cu-ferrite. Initially, Cu-ferrite nanoparticles were synthesized using a hydrothermal method. Subsequently, the addition of fumaric acid to the Cu-ferrite nanoparticles activated the F0 component, inducing MOF nucleation. As a result, the Cu-ferrite core was gradually covered with a crystalline MOF shell, forming the MOF@Cu-ferrite structure. The MOF@Cu-ferrite nanocomposite is characterized by high porosity, numerous accessible surface functional sites, good crystalline stability, low toxicity of copper, excellent water dispersion, high magnetic properties, and cost-effectiveness. This study investigates the effect of the MOF@Cu-ferrite nanocomposite on the MRI signal intensity. T2-weighted images were obtained using MRI scanner at various iron concentrations of the magnetic nanocomposite, showing a significant change in signal intensity with increasing iron concentration. The transverse relaxivity rate (r2) for different iron concentrations was found to be 504.7 mM^-1s^-1. The results showed that Cu-ferrite magnetic nanoparticles coated with MOF have significant potential as negative contrast agents in MRI, reducing T2 relaxation time and improve contrast intensity in MR images.