نشریه زیست فناوری دانشگاه تربیت مدرس
سال پانزدهم شماره 2 (پیاپی 41، بهار 1403)

Cancer is one of the leading causes of death worldwide. Breast cancer is the most common cancer among women and causes a high number of annual deaths. The most reliable method for successful cancer management is accurate and early diagnosis. On the other hand, the lack of timely diagnosis leads to the spread of cancer in the body, making it difficult to treat and control. The gold standard method for breast cancer diagnosis is biopsy. Usually, visual inspection and manual assesement are used to diagnose cancer, where the pathologist examines the histopathology slides under a microscope which is error-prone and time- consuming procedure and requires years of expertise. Therefore, computer-aided diagnosis is essential to help physicians improve the efficiency of interpreting medical images. In this study, we use deep learning models, especially convolutional neural networks (CNNs) to detect whether or not histopathological images are cancerous. The AUC, Precision and F1-score obtained using the pre-trained Incetion-V3 deep neural network are 98.36%, 95.28% and,97.25% respectively, and the same parameters for the pre-trained ResNet-18 deep neural network are equal to 97.90 %, 97.46% and 98.22%. The presented models are able to provide reliable diagnosis results for different morphologies of breast tissues.

One of the most important hosts used for production of recombinant proteins is Escherichia Coli. For example, the most therapeutic proteins approved by FDA are produced in Escherichia Coli. Comprehensive knowledge about biologic nature of Escherichia Coli had made this microorganism to a favorable factory for production of recombinant proteins. Accessibility of this information have led to rational manipulation for changing of this small factory to intelligent system can make different recombinant proteins easier. So that, many engineered and useful strains were obtained from wild type and parental strains can produce high amount of diverse and stable recombinant proteins in lab and industrial scale. In this review, we will present some of these strains that are more widely used.

In recent years, significant efforts have been focused on advancements of novel biomaterials based on natural polymers and utilization of efficient methods such as skin tissue engineering for wound treatment. In this study, a 3D printed polycaprolactone (PCL) scaffold coated via immersion in a 1:4 blend of 40% silk fibroin from Bombyx mori cocoons and TEMPO-oxidized was developed. The pore size and the porosity were 180 µm and 85%, respectively. The results demonstrated an enhancement in exudate absorption (swelling and water uptake of 1342% and 80%, respectively), improvement in storage modulus (G’) from 500 to 4000 Pa, as well as viscoelasticity up to 60%, which all are favorable for wound dressing applications. Moreover, the wettability and biodegradability studies revealed an overall increase in contact angle and degradation rate of 19.9°±3, and 95%, respectively. Cell viability and migration studies on fibroblastic cells (L929) using MTT assay, DAPI/ Phalloidin staining, and scratch test showed over 90% viability up to 7 days and complete scratch repair within 24 hours. These findings show that 3D printed PCL scaffolds coated with silk fibroin and oxidized nanocellulose are promising for wound healing applications and might pave the way to natural polymer-based wound dressings.

Ensuring food security in developing countries is highly challenging due to low productivity of the agriculture sector, degradation of natural resources, crop losses, less value addition, and high population growth. therefore, researchers are striving to adopt newer technologies to increase the supply of agricultural products. one of these technologies is nanotechnology. Nanotechnology is the science of producing, manufacturing and using materials at the atomic and molecular levels and it can transform various industries, including the agricultural industry, with the help of new tools. Nanotechnology By using new materials such as nanofertilizers, nanoherbicides, nanopesticides, etc., strengthens the soil and increases the growth of plants and with the help of new tools such as nano-sensors and intelligent delivery systems, identifies pathogenes in plants.  For these reasons nanotechnology can be a promising way to increase the productivity of agricultural products.

In this study, 50 Staphylococcus aureus samples from Baghdad Hospital were collected and examined, 17 samples were infected with methicillin-resistant Staphylococcus aureus (MRSA) and 5 samples were infected with vancomycin-resistant Staphylococcus aureus (VRSA). The sensitivity of the isolates against different antimicrobial agents was evaluated using the VITEK2 standard system. According to CLSI, the minimum inhibitory concentration (MIC) values of zinc oxide quantum dots (ZnO-QDs) were also tested by the Muller-Hinton dilution method. In addition, polymerase chain reaction (PCR) was performed to identify vanA and mecA genes. The antibacterial effects of ZnO-QDs on VRSA were higher than MRSA isolates.

Gene delivery using the force of a magnetic field is called magnetofection. The purpose of this study is the synthesis and characterization of magnetic iron oxide nanoparticles (Fe3O4) as the core of the transfer agent and to investigate the effect of alternating magnetic field on transfection efficiency. For this purpose, the first magnetic nanoparticles (MNP) were synthesized by coprecipitation method. The magnetic properties of the synthesized MNP were investigated by vibrating sample magnetometer (VSM), appearance characteristics, and zeta potential of the synthesized particles were evaluated  using transmission electron microscopy (TEM) and dynamic light scattering (DLS). Then, using magnetic nanoparticles (MNP), polyethylene imine (PEI) and plasmid DNA containing luciferase reporter gene (pDNA), PEI-pDNA binary complex and MNP-PEI-pDNA ternary complex were synthesized. The complexes were evaluated using DLS and gel retardation techniques. The results of DLS and gel retardation technique showed that the complexes have a suitable surface charge and polyethyleneimine is well joined to pDNA and neutralized its negative charge. Finaly, human breast cancer cell lines (MCF-7) and Hek293T cells were transfected by ternary complex in the presence of 50 Hz alternating magnetic field. Cell viability was measured using the MTT test. The obtained results showed that the transfection efficiency in the cells that were transfected with the ternary complex in the presence of alternating magnetic field increased significantly compared to the control group, without any additional toxicity (P ≤ 0.05).

APC gene in ctDNA has been proposed as a potential biomarker for cancer diagnosis. A biosensor based on a multi-walled carbon nanotube (MWCNT) and DNA probe with fluorophore FAM (6-carboxyfluorescein) for detection of APC gene in ctDNA was developed to identify patients with colorectal cancer (CRC).This method was designed based on the adsorption and immobilization of FAM-labeled single-stranded DNA (ssDNA) on MWCNT, which leads to the quenching of FAM fluorescence emission. By adding its cDNA could release single-stranded DNA probe (ssDNA) from the MWCNT surface and a double-stranded DNA (dsDNA) was formed. It led to the return of FAM fluorescence emission. While in the case of non-complementary DNA the corresponding dsDNA was not formed and therefore we did not have the return of FAM fluorescence emission. The results of this study showed that the biosensor based on carbon nanotubes can be used as a high-sensitivity method for the early detection of CRC.

Pathogen growth in vitro is one of the major problems in plant micropropagation, so the most important stage of in vitro culture of plants is disinfection of the cultures. In the common methods of disinfection, the media and plant materials, apparatus such as autoclaves and chemicals disinfectents are used, which causes the time of this process and the costs to increase. This research objective to improve the disinfection of Iris hollandica cv. Apollo scales using different plant essential oils (thyme, cumin and savory) and the methods of using essential oils as disinfectants, the use of essential oils in the medium and the use of essential oils fumigation was done in four independent experiments. The use of essential oils of thyme, cumin, and savory completely prevented both contamination of the culture medium and contamination of the explant. The best disinfection method was when the essential oils were used in combination with the culture medium. Bacterial contamination was better controlled at concentrations of 0.125 to 0.25%, but the concentration of 0.25% of essential oils resulted in better control of fungal infection. The least browning of iris scale explants was observed at a concentration of 0.125. The technique presented in this study can significantly reduce the cost of electricity and lighting, as well as personnel costs. Therefore, this method can introduce a practical and cost-effective technique for plant micropropagation.