mehdi rezayat

In recent years, use of biodegradable polymers based nanoparticles has received high interest in the development of vaccines delivery vehicles. The aim of study was to prepare chitosan nanoparticles (CS NPs) for loading Echis carinatus (EC) venom and evaluate their potential as an adjuvant and antigen delivery system on a pilot scale. CS NPs were prepared using ionic gelation method, and their characteristics were optimized. Venom-loaded CS NPs prepared under optimum conditions and traditional venom-loaded adjuvants were used to hyperimmunization of horse. Under optimum conditions, particle size, polydispersity index (PDI), and zeta potential of CS NPs were 127.9 ± 15 nm, 0.29, and .8 ± 1.92 mV, while those of venom-loaded CS NPs were 182.4 ± 20 nm, 0.35, .8 ± 1.98 mv, respectively. All CS NPs had integrated surface and good morphology. Optimum loading concentration of EC venom was 500 μg/mL. The loading capacity (LC) and loading efficiency (LE) were 87% and 94%, respectively, and release profile of venom-loaded CS NPs showed suitable correlation with Higuchi kinetics. Stability test showed good stability of the venom encapsulated in CS NPs. Furthermore, antivenom plasma obtained using the new antigen delivery system had significantly higher potency (P

Spinal cord injury (SCI) is a serious disabling condition associated with paralysis. Owing to suitable effects of hydrogels compared to preformed scaffolds, in this study a hydrogel based biomaterial, Matrigel, was applied. Matrigel is a termogel that forms nanofibers and hydrogel above 20°C. It contains laminin, nidogen and some growth factors that induce neural differentiation.
A moderate spinal cord contusion was performed in adult rats and 10 days after injury, matrigel was implanted. Then, they follow up via Basso, Beattie, Bresnahan test for 42 days. Cresyl violet staining was performed as a histopatological analysis.
Our data indicated less inflammation and dark cells in Matrigel group compared to control group. Locomotor test showed significant improvement of motor recovery in Matrigel group.
Our results suggest that Matrigel via some growth factors and adhesive molecules may have beneficial effects on functional recovery in SCI.

Ischemia-reperfusion injury is the tissue damage caused when blood supply returns to the tissue after a period of ischemia or lack of oxygen. Ischemia-reperfusion brain injury initiates an inflammatory response involving the expression of adhesion molecules and cytokines. Twenty–four male Wistar rats (250-300 g body wt) were used in this study. The animals were divided into four groups of 6 rats each: I: Control group that was subjected to ischemia-reperfusion, II: Ischemia-reperfusion group that was subjected to all surgical procedures, III: Drug group that received pentoxifylline (200, 400 and 600 mg/kg) 60 min before and after ischemia and IV: Vehicle group that received saline. Seventy two h after ischemia-reperfusion, the hippocampus was taken for studying the changes in bcl-2 gene expression. We used quantitative real-time PCR for the detection of bcl-2 gene expression in ischemia and drug groups and then compared them to normal samples. The results showed the gene dosage ratio of 0.66 and 1.5 for ischemia group and the drug groups, respectively. The results also showed the bcl-2 gene expression declined in ischemia group as compared to the drug group. Furthermore, we observed a significant difference in the bcl-2 gene expression between ischemia and drug groups. These findings are consistent with anti-apoptotic properties of bcl-2 gene. Furthermore this method provides a powerful tool for the investigators to study brain ischemia and respond to the treatment drugs with anti-apoptotic agents.

Vibrio cholera toxin B (CTB) subunit is the pentameric non-toxic portion of cholera toxin (CT) which is responsible for the holotoxin binding to the GM1 ganglioside receptor present on nucleated cells. this study was to produce, purify, and verify recombinant CTB (rCTB) subunitin prokaryotic system.

In this experimental study, rCTB expression vector (pET-28a) which could be induced in E. coli (BL21) was designed and synthesized. Then the recombinant expression strains containing the result of IPTG interaction were induced and the rCTB was generated on small and large scales. The rCTB produced through Ni2+-charged resin, after refolding and free of possible CTA contaminants, was extracted. After purification, rCTB was verified by Western blotting.

The results indicated the level of purification to be about 480µg of purified active pentameric rCTB for each liter of the induced culture. Also, Western blotting analysis showed that recombinant CTB is strongly and specifically recognized by polyclonal antibodies against the cholera toxin.

The findings of this study demonstrated that E.coli is an available host for production of CTB. In addition, the designed host and vector can be used in large scale production of this protein.

Serotonin (5HT) has been shown to be a mitogenic factor in several carcinomas. Its mitogenic effect is elicited through a wide range of 5HT receptor subtypes. In this study, the effects of 5HT, 5HT3 (1-phenylbiguanide hydrochloride) and 5HT4 (cisapride) agonists in promoting the growth of the HT29 cell line and the growth-inhibition effect of the 5HT3 receptor antagonist (Y-25130 hydrochloride) and 5HT4 receptor antagonist (RS 23597-190) were investigated. The expressions of 5HT3 and 5HT4 receptors in human colon cancer tissues and the HT29 cell line were studied. The growth-promoting and growth-inhibition effects of 5-HT, 5HT3 and 5HT4 agonists and antagonists on the HT29 cell line were studied using MTT assay. Receptor expression has been demonstrated by western blotting. The results showed that 5HT, 5HT3, and 5HT4 agonists caused significant proliferation of HT29 cells. 5HT3 and 5HT4 receptor antagonists had an inhibitory effect on the growth of these cells. Western blot analysis gave bands from colon tissue extracts and the HT29 cell line. The results indicate which 5HT3 and 5HT4 receptors are significantly expressed in both colon cancer tissue and the HT29 cell line. Expression for the 5HT3 receptor is more potent. Furthermore, 5HT plays a mitogenic role in colon cancer cells and antagonists of 5HT3, and 5HT4 receptors can inhibit cancer cell growth.