فصلنامه تازه های بیوتکنولوژی سلولی مولکولی
پیاپی 34 (بهار 1398)

Nowadays, design and synthesis of efficient drug delivery systems are of vital importance in order to optimize the efficacy of therapeutics and reducing side effects. So far, many drug delivery systems have been designed, among them, natural polymer-based systems have attracted the most attention. Silk fibroin (SF) as a natural polymer have several unique properties including excellent biocompatibility, biodegradability, good mechanical behavior, ease of processability with ability to fabricate various structures e.g., nanoparticles, microparticles, fibers, hydrogels, films, that makes it a suitable material for biomedical applications especially drug delivery vehicles. In this review, we discuss the drug delivery applications of SF, in detail.

Glutamate-specific endopeptidase (GSE, EC 3.4.21.19) is belonging to the serine protease family enzymes. A glutamate-specific endopeptidase has the ability to cleavage peptide bonds for the protein structure analysis, solid phase synthesis of peptides and preparation of nanotubes. The purpose of this investigation was to produce glutamate endopeptidase enzyme from the Bacillus licheniformis SL-1from isolated from Aran-Bidgol salt lake in Iran.

In this study, the expression of glutamate-endopeptidase enzyme from the B. licheniformis SL-1 wasinvestigated in periplasmic spaces of E. coli BL21 in different temperature (16ᴼC, 20ᴼC, 37ᴼC) and different concentrations of inducer (0.4, 1, 2 mM).

Analysis the results demonstrated that periplasmic and soluble expression of glutamate endopeptidase was observed in E. coli BL21at 37ᴼC and 2 mM concentration of IPTG.

Qualitative investigation of the expression results revealed that the expression of the enzyme is temperature-dependant and requires higher concentrations of IPTG. This preliminary study provides the possibility of recombinant enzyme production in E. coli BL21 expression system. In order to produce large scale of this enzyme, other expression systems as well as alternative purification systems can be studied.

Taxol is a known substrate for P-glycoprotein, which induces drug resistance to cancerous cells. Therefore radiolabeled taxol can be a suitable probe for imaging of the P-glycoprotein transport ability to determine drug resistance. The aim of this study was to provide labeled taxol and to determine the rate of uptake in the tumor to evaluate the location of the tumor and the extent of tumor resistance to the drug.

Taxol was radiolabeled with 99mTc by direct labeling method and after that radiochemical purity of complex was investigated. The stability and biodistribution of radiocomplex in the mice bearing melanoma tumor was performed.

The radiocomplex was prepared with radiochemical purity more than 90%. The complex was stable (68.64%) up to 48 h. The biodistribution results showed high tumor uptake (4.51%ID/g) for radiocomplex.

High uptake of the complex in the liver as a metabolic and excretory organ and a related tumor was observed. The accumulation of radioactivity in the tumor indicates that the cells in the melanoma tumor are susceptible to taxol absorption and it is possible to detect the sites involved with the tumor using this radiocomplex. In general, based on the findings, it can be concluded that the compound has binding affinity to the tumor and, despite the biliary excretion, can be used as a diagnostic radiopharmaceutical.

Eradicating infections is difficult due to the presence of genes on the introns, especially the beta-lactamase enzymes and The importance of their resistance is high.The purpose of this study was to determine the beta-lactamase genes (OXA-2 , OXA-10) , Integron class 1 and antibiotic resistance.

In this cross sectional descriptive study, 120 Pseudomonas isolates were collected from Shiraz Burn Hospital during summer of 1395. After confirmation by biochemical tests, The presence of beta-lactamase genes was evaluated by using antibiotic discs and PCR method.

78.5% of the isolates had OXA-10 gene, 77.57% of the OXA-2 gene, 34.58% containing Int1, and 95.38% of the samples were MDR.Maximum resistant was seen in cefepime(79.43%) and the minimum was for to tobramycin(10.28%).

Class1 integron, 2-oxa and 10-oxa beta-lactamase genes, did not show up a meaningful relationship at the same time.the production of beta-lactamase enhances the increasing resistance and their frequency is increasing according to the results of other studies. This will lead more control over the prescription and use of antibiotics.

In the study , synergistic effect of green tea (camellia sinesis) extract and treadmill aerobic exercise on wound healing in streptozotocin induced diabetic mice has been investigated.  

The number of 50 male mice with the approximately weight of 30-35 gram health and adult are put in 5 groups: non diabetic – immobile , diabetic - immobile, diabetic exercise - diabetic and  immobile with green tea extract , diabetic with synergism of exercise and green tea extract. After inducing of diabetes using sterptozotocin mice were killed and in days 3-7-14-21 macroscopic and histopathologic analysis were performed.  

The results indicated that in synergistic group of  green tea extract and treadmill exercise , wound area decreased and fibroblast  increased after 7 days significantly compared with other groups (p<0.001).PMN cells decreased after 3 days significantly compared with other groups (p<0.001).  

The results suggest that green tea extract and treadmill exercise have synergistic effect on wound healing in diabetic mice.

micronutrients like iron as a cofactor plays an important role in the construction of a number of antioxidant enzymes. In this study the effects of salinity and iron on expression levels of ascorbate peroxidase (Cm APX) in Sistan melon Landrace were studied.

three Sistan melon Landraces including Sefidak, Ghandak and Khatdar at three salinity levels (0, 250 and 350 mM, NaCl) and two levels of Fe (2 gr per thousand and controls sprayed with pure water) in a randomized complete block design with three replications at the Institute of Biotechnology, University of Zabol in the form of flower pot was planted. Then Cm APX gene expression was studied using Real Time PCR

Salinity and foliar application of iron had a significant effect on Cm APX gene expression. Sefidak Cm APX expression levels in comparison with the control salinity increased with the use of iron as well as its expression increased. The lowest Khatdar Cm APX gene expression compared to control salinity level of 350 mM showed that the use of the expression levels of the iron recovered.

The application of trace elements iron, central power plants to salinity. The Cm APX gene expression reflects the fact that the Ghandak as resistant cultivars and Khatdar as susceptible to salinity is underlined.

Vincristine is a herbal anticancer drug which is used to treat a wide range of cancers such as lymphoma. Niosomes are important drug carriers. The aim of this study was to prepare PEGylated niosomal form of vincristine in order to increase its efficacy in lymph nodes’ cancer.

PEGylated niosomal vincristine (PEG-nVCR) was prepared by thin film hydration method. Physicochemical properties of niosomal formulation, such as size, zeta potential, encapsulation efficacy, release rate, stability and cytotoxicity were studied. Mean size and zeta potential was measured by dynamic light scattering. Releasing rate of drug from niosomes was determined by dialysis diffusion method. Cytotoxicity study was evaluated by MTT assay.

mean particle size and zeta potential was obtained about 118.1±2.3 nm and -21.5±1.2 mV, respectively. The cytotoxic effect of PEG-nVCR against Raji cells was significantly higher than of free drug. Stability study indicated that PEG-nVCR was stable for at least two months. Release of drug from PEG-nVCR formulation showed a sustained release pattern, while the free drug release rate reached to 100 % less than 6 hours.

our findings demonstrated that the use of niosomes as a drug carrier plays an important role in anticancer efficacy of vincristine and can be considered as an alternative to conventional form.

Meticillin resistant Staphylococcus aureus (MRSA) has become one of the major public-health concerns in recent years due to resistance to antimicrobial drugs and agents. This Study aims to diagnose of MRSA isolates by molecular and phenotypic methods and to detect of the antibiotic resistance pattern in MRSA strains in clinical patient samples in Rasht.

This cross-sectional (descriptive-analytical) study was conducted from April to September 2016. 76 isolates of Staphylococcus were collected from some hospitals in Rasht and was characterized by varius biochemical tests of Staphylococcus aureus species. A disc diffusion method was performed to identify MRSA strains. The antibiotic resistance pattern of isolates was done using disc diffusion method against six antibiotics based on Clinical and Laboratory Standards Institute (CLSI) protocol. Then, Polymerase Chain Reaction (PCR) was performed with specific primers to mecA gene. Also, sequencing was done in mecA positive PCR products. Data were analyzed using SPSS 23 software. 

The results of this study, showed that 69 (90.8%) out of 76 isolates of Staphylococcus were S.aureus. The rate of MRSA strains in the phenotypic(disk diffusion) and PCR methods were 71% and 62.3%, respectively. The S. aureus isolates exhibited the most sensitivity and resistance to gentamicin(72.46%) and bacitracin(82.6%), respectively. No significant correlation was found between MRSA isolates and type of sample(P>0.05).

The findings showed that the presence of MRSA strains were remarkable in the hospital samples in Rasht because of the overuse of antibiotics for the treatment of diseases.

Candida Albicans is the most important cause of vulvovaginal candidiasis and resistance to azoles can occur via various mechanisms including, change in the ERG11 gene. This study aim was to identification of ERG11 gene mutations in drug resistant Candida albicans isolated from patients with Candida vaginitis and its association with infertility in Iranian women.

From 100 patients with vaginitis Candida Albicans species were isolated by using chromogen agar culture . The drug sensitivity was determined with standard protocol, diffusion disc test. Then extraction genome from resistance species and was used PCR and sequencing for investigation of ERG11 gene mutations. For detection of sperm parameters disorders and relation with infertility, normal sperm was placed adjacent to sensitive and resistance Candida Albicans by different concentrations and times.

From 100 patients, 40 samples of Candida albicans were isolated that 2 samples were fluconazole and ketoconazole-resistant. ERG11 gene mutations e in 2 samples were, conversion and insertion. In 10000 and 100000 CFU/ml concentrations, 4 hours and with 3 repeated, was observed significant relation to agglutination and reduction in motility of the sperms (P<0.05).

This study results showed that antibiotic resistance can be increased in Candida albicans with mutation in the ERG11 gene and this Candida vaginitis infections, can associated with infertility in women.

Multiple sclerosis (MS) is an autoimmune inflammatory disease that attacks myelinated axons in the central nervous system (CNS) resulting in destroying the myelin and the axon. According to high prevalence of disease in Iran, it needs to study different aspects of disease including factors influencing the pathogenesis and the other risk factors. Various type of genetic variants including polymorphisms may could highlight the relation between genetic and disease. In this study, we explored the relationship between IL-4 receptor polymorphism rs1801275 and disease risk.

In this study, IL-4receptor gene polymorphism was analyzed in a case-control study. All patients were selected as relapsing remitting (RR, n=100) and the control group consisted of 100 healthy (c, n= 100). High resolution melting analysis (HRMA) based on real-time PCR was performed to identify gene variation involved in disease. The results were analyzed by SPSS 20 software and also Hardy Weinberg equilibrium was tested for SNP. Also degree of heterozygosity and population analysis PIC was performed.

The results showed samples from control group consisted of 45% wild genotype (AA), 40% heterozygote (AG) and 15% homozygote (GG) for polymorphism rs1801275 while there was in patient group 20% wild genotype (AA), 58% heterozygote (AG) and 22% homozygote (GG).

These results suggest that there was significant difference in allele count between control and patient groups. The allele frequency of IL-4 receptor polymorphism rs1801275was found significantly higher in patients (P-Value = 0.022). IL4R polymorphisms may have a disease-promoting role in this population.