نشریه زیست فناوری دانشگاه تربیت مدرس
سال سیزدهم شماره 1 (پیاپی 32، زمستان 1400)

Transforming growth factor beta (TGF-β), is a small homodimeric signaling protein. The TGF-β isoforms (TGFβ1, β2 and β3) are involved in many cellular processes including growth inhibition, extracellular matrix remodeling, tissue development, cell migration, invasion and immune regulation. For research aims, TGFβs are overexpressed using recombinant eukaryotic cell or bacterial expression systems. For achieving an efficient purification of TGF-β by immobilized metal ion affinity chromatography (IMAC), a histidine tag was placed either at the C-terminal (C-TGFβ) or N-terminal (N-TGFβ) region of the sequence and the effect of His-tag on TGF-β structure has been studied by computational tools. Proteins 3D structures were modeled using MODELLER software and molecular dynamics simulation of native TGF-β and modelled proteins, N-TGFβ and C-TGFβ were studied in water by GROMACS package. Protein dynamics modeling indicated that the His-tag attached at the C-terminus but not at the N-terminus of the TGF-β can affect the fluctuations of amino acids and protein structure. It is concluded that the C-terminal tagging may cause distortion and misfolding in the structure.

Mutation in microbial strains to increase coenzyme Q10 production is one of the successful strategies for strain development. Therefore, in this study, the production of coenzyme Q10 by Gluconobacter oxydans H621 was investigated through chemical mutation with nitrosoguanidine using the response surface methodology. Nitrosoguanidine was used to induce mutations at different concentrations (2.79 - 4.21 mg/mL) and treatment times (11.89 – 33.12 minutes), which was designed by a central composite design. The detection of mutant strains was investigated through their ability to grow in medium containing 160 μg/mL of menadione. The mutant strains were then examined for coenzyme Q10 and dry cell weight production. The results showed that no mutant strains were obtained at a concentration of 4 mg/ml and above. The highest number of mutant colonies was obtained at a concentration of 2.79 mg/mL of nitrosoguanidine and treatment time of 22.5 minutes. It was also found that the concentration of nitrosoguanidine was effective on mutagenesis but the treatment time had a little effect. The mutant strain that was able to produce the highest amount of coenzyme Q10 produced 5.2 mg/L, which was twice as much as the parent strain. According to the results of this study, it is concluded that by inducing mutation using nitrosoguanidine, mutant strains can be generated in Gluconobacter oxydans H621 that are able to produce more coenzyme Q10 than the parent strain.

In recent years, the use of medicinal plants has increased significantly. Essential oils are one of the most important secondary metabolites in plants with promising potentials to promote health. Paying attention to the quality and effectiveness of medicinal plant products is important. Use of free essential oils due to volatility, low stability, poor solubility in water and low bioavailability, limit both their use and effectiveness. The most important tool to increase the quality of essential oil is the use of nanoparticles as carriers. This study aimed to investigate the nanoencapsulation of essential oils of medicinal plants and its effect on increasing the stability of essential oils and improving the quality of drug delivery systems.

In the present study, the data of scientific research articles have been used to investigate the use of nanoparticles in increasing the effectiveness of the essential oils.

Drug-carrier nanoparticles include various materials such as nano polymers, dendrimers, etc. that can have different morphology and sizes depending on their synthesis method. Technology of nanoencapsulation of essential oils is used to increase stability, purposefulness and control the release time of essential oil in the human. One of the advantages of targeted drug delivery is the accurate and intelligent accumulation of essential oil as a drug at the target site, thus increasing the stability and pharmacological effects of the essential oil on the organs in the human.

Nanocapsules containing essential oils of medicinal plants have significantly increased the effectiveness of essential oils in medical applications.

Mechanical properties of living cells play an important role in helping to understand cell physiology and pathology. Evaluation of mechanical properties of cells may potentially lead to new mechanical diagnostic methods for some of these diseases. In this study, viscoelastic properties of the outer layer (cytoplasm and membrane) were extracted using standard linear solid model. Finite element modeling of the two cell layers is performed and the model is validated by experimental data. In the two-layer model, the effect of the radius of the nucleus and the location of the nucleus in the cell are investigated on the cell properties. By reducing the cytoplasmic radius ratio up to 43%, the whole cell properties follow the cytoplasmic properties and the effect of the nucleus can be neglected. The 50-second displacement change at a radial ratio of 0.53 increased to 4.5% compared to radial ratio of 1.58.  At a radial ratio of 0.43, a change in cell behavior was observed compared to the previous one, with a displacement change equals to 6.8% compared to radial ratio of 1.85 and a displacement reduction of 9.5% at a radial ratio of 0.53. The results demonstrate that the location of the nucleus and the ratio of the radius of the cytoplasm to the radius of the nucleus can effectively influence the viscoelastic properties and mechanical behavior of the cell.

Proteases are the most important industrial enzymes. Bacillus bacteria are commonly used to produce these enzymes. The aim of this study was cloning, sequencing, expression and bioinformatics study of aprX serine protease gene extracted from Bacillus licheniformis.

In this study, after extraction of bacterial DNA, aprX serine protease genes was isolated from Bacillus licheniformis and cloned into pTG19-T vector and then subcloned in pET28a vector. The molecular structure, its biochemical and phylogenetic properties were investigated and three-dimensional structure of the cloned enzyme was predicted. For the induction of gene expression and protein production of the recombinant serine protease IPTG was used at different concentrations, different temperatures and different time periods. Confirmation of aprX gene expression was performed by SDS-PAGE and dot blot analysis. Then, the activity of recombinant protease enzyme was measured at different temperatures and pHs.

Cloning was confirmed by sequencing. Based on the results of phylogenetic studies, the obtained protein sequence showed a high similarity to the sequences of other Bacillus species. After evaluating the drawn models, it was found that the models provided by RAPTROX and I-TASSER software were desirable models for predicting the three dimentional structure of this protease. The recombinant protein production was successfully induced by IPTG induction in the host containing the plasmid pET28a-aprX. The highest expression values were obtained at 25 ° C for 20 hours with 0/5 mM IPTG. Also, the recombinant protein produced showed the highest activity at 50 ° C and pH 8.

Investigation of factors affecting endothelial cell proliferation is an essential part of angiogenesis studies. Given the importance of inhibiting angiogenesis in the treatment of cancers, and due to the side effects and high cost of anti-angiogenic drugs such as Avastin, the use of physical agents to aid in treatment and reduce the need for high doses of the drug is noteworthy. Magnetic fields are of interest due to their long-distance and non-invasive effects, and many studies have been conducted on their effects on biological phenomena, including angiogenesis, with inconsistent results. In the present study, the effect of a 2 mT alternating magnetic field with a frequency of 200 Hz and Austin on the proliferation of human umbilical vein endothelial cells (HUVEC) was investigated. Cells were treated for 48 hours under a mixture of 50 μg/ml solution of vascular endothelial growth factor (VEGEF) and Avastin at concentrations (zero (drug control), 50, 100, 200 and 400 μg/ml) as well as field treatment groups for They were exposed to magnetic fields for 3, 6, 12, 24 and 48 hours. Then, cell proliferation was assessed using Alamar Blue colorimetric test. Data were analyzed by three-way analysis of variance. According to the findings, the exposure times of 12, 24 and 48 hours showed a significant reduction in cell proliferation compared to the control group, but this difference was not significant in the 3 and 6 hour treatments. Also, the degree of interaction of these factors with each other on HUVEC proliferation was investigated.

Cervical cancer is the fourth most common cancer among women. In recent years, attention has increased to natural products such as curcumin with anti-cancer potential as a therapeutic supplement. However, due to its poor solubility, its clinical use is limited. In this regard, in this study, to improve clinical parameters, the effects of nanocurcumin on the angiogenesis inhibition of cervical cancer were investigated and compared with free curcumin.

MTT method was used to evaluate the proliferation of the HeLa cell line with free curcumin and nanocurcumin at different doses and time intervals and the rate of apoptosis was assessed by flow cytometry. Then, the expression of the vascular endothelial growth factor (VEGF-A) gene in HeLa cells was measured by Real-Time PCR and Western blotting, respectively.

According to IC50 for 48 hours in the HeLa cell line, which was 15 μM/ml and 50 μM/ml for nanocurcumin and free curcumin, respectively, the nanocurcumin showed a greater lethal effect. VEGF-A gene expression (p <0.0001) and protein level (p <0.01) were significantly lower following nano-curcumin treatment than free curcumin.

Nanocarrier increased the solubility and further inhibited the proliferation of cervical cancer HeLa cells and was three times more effective than curcumin in inhibiting angiogenesis at the same concentration. Therefore, nanocurcumin can be a good option for drug supplementation along with routine cervical cancer treatment.

Cell substrates play a crucial role in tissue engineering and biomaterial science. Various studies are performed to develop the appropriate cell substrates for using in vitro and in vivo. Therefore, a biocompatible substrate that mimics the native extracellular matrix properties with specified surface topography as a biomimicry factor is necessary under ''the novel cell substrates development'' approaches. Our aim in the current study was to design, synthesize, and characterize a substrate with aligned nanometric arrays on the surface. The rapid and easy capabilities of Polydimethylsiloxane to receive chemical and physical characteristics with simple modifications, make it a promised candidate for the cell substrate. The obtained results from the atomic force and scanning electron microscopy showed the formation of 305±19 and 571±141 nanometers wrinkled nanoarrays after regulating the substrate under lateral traction during the plasma treatment times of 100 and 200s. Then, the behavior of a human foreskin fibroblast cell, in terms of adhesion, growth, viability, and morphology on this substrate was investigated. Increasing the plasma treatment time increased both nanoarray size and surface hydrophilicity, resulting in improved 17 and 46% of cell attachment quality, respectively. Additionally, the presence of the designed nanowrinkles surprisingly improved the number of the attached cells. The nanowrinkles caused the cells to align perfectly through the substrate's surface due to the contact guidance phenomena. Consequently, the biocompatible Polydimethylsiloxane substrate of this study with suitable chemical, mechanical, and physical properties showed fit capacities as a novel aligned cell culture platform.

Rapid test methods are laboratory instruments that can be used in the point of care and for suspicious cases. In an ideal rapid detection method, the steps for preparing a sample to obtain an analytical result should be as short as possible, and unskilled operators should be able to execute it and understand the result. To accomplish such a process, it is better to perform all the steps including sample preparation, detection procedure and acquisition of an intelligible signal in one device. These assay systems can include microfluidic chips, paper-based sensors, or even single-tube reactions. Corona Pandemic offers many products for the rapid detection of the Covid 19 virus, which diffrent products were commercially developed. Due to the sensitivity of the diagnosis at different stages of the disease, only a small number of technologies could be applied in practice. In this review article, these products are categorized and reviewed based on technological properties. Also, these technologies have been compared in terms of important components such as sensitivity, accuracy, cost and speed of the process in the diagnosis and management and control of COVID-19 pandemic. Also the application of each technology is explained. Finally, the best technology that can play a major role is introduced.

Aptamers are single-stranded sequences of RNA, DNA, or highly specific proteins that tend to bind to a wide range of target molecules. Aptamers are widely used in various fields, especially medicine and diagnostics, and are similar in their application to antibodies. There are many benefits to using aptamer instead of antibodies, such as low cost, longer life, increased tissue permeability, and more. There are several methods for producing aptamer that in silico methods can shorten and simplify the steps of aptamer production. With aptamer modeling, a set of in silico methods such as modeling, docking, and molecular dynamics can be used to screen for the best aptamer sequence. In this article, a review of the types of aptamers, their structure and design methods in silico is briefly stated.