sara amini - Academia.edu (original) (raw)

Papers by sara amini

Research paper thumbnail of Cytotoxic and Apoptotic Effects of Three Types of Silver-Iron Oxide Binary Hybrid Nanoparticles

Current Pharmaceutical Biotechnology, 2016

Multifunctional nanostructures have received great deal of attention in biomedical area due to th... more Multifunctional nanostructures have received great deal of attention in biomedical area due to their capabilities in the development of new therapeutic and diagnostic agents. Silver and iron oxide nanoparticles, owing to their specific characteristics, are considered to develop bifunctional hybrid nanoparticles for magnetic delivery of silver nanoparticles as cytotoxic agent toward cancer cells. This study was designed to explore the in-vitro cytotoxic and apoptotic activities of three different silver-iron oxide binary hybrid nanoparticles on human liver hepatocellular carcinoma cell line. Three different silver-iron oxide binary hybrid nanoparticles were synthesized and characterized through the designed procedures. Apoptosis induction was investigated through flow cytometry and the influence on bax gene expression level was analyzed using quantitative real time polymerase chain reaction. All the three types of silver-iron oxide hybrid nanoparticles (possessing different characteristics) exhibited cytotoxic and apoptotic effects. Furthermore, the up regulation of bax gene expression suggested the involvement of the intrinsic pathway of apoptosis. Some of the transcription regulators which could interact with bax gene promoter were analyzed and found out to be mostly contributed in the stress responses. Among the test nanoparticles, the strongest cytotoxic and apoptotic effect was induced by the binary hybrid nanoparticle which was synthesized with glucose as reducing agent; suggesting that the biological activity was affected by different characteristics of the designed nanoparticles. Combined properties of silver and magnetic nanoparticles in the binary hybrid nanoparticles, provide a great potential to be exploited in the cancer therapy, where the combination of cytotoxicity and magnetic targeting is desired.

Research paper thumbnail of Comparative Study on Characteristics and Cytotoxicity of Bifunctional Magnetic-Silver Nanostructures: Synthesized Using Three Different Reducing Agents

Acta Metallurgica Sinica (English Letters), 2016

Research paper thumbnail of Isolation and Characterization of Some Moderately Halophilic Bacteria with Lipase Activity

Research paper thumbnail of The Properties of a New Endodontic Material

Journal of Endodontics, 2008

The purpose of this study was to analyze the physical properties and chemical compositions of a n... more The purpose of this study was to analyze the physical properties and chemical compositions of a new experimental cement (NEC) and compare them with mineral trioxide aggregate (MTA); pH, working time, setting time, dimensional changes following setting, flow, film thickness, and chemical composition of NEC and MTA were assessed. For chemical compositions, all specimens were imaged and analyzed by scanning electron microscopy and electron probe microanalysis (EPMA). The physical properties were performed according to ISO 6876:2001. Working time, pH, and dimensional changes of NEC and MTA showed similar results. Shorter setting time was obtained with the NEC compared with MTA (p Ͻ 0.05). The NEC showed more flow than MTA. In addition, the film thickness of the NEC was considerably less than the MTA (p Ͻ 0.01 and p Ͻ 0.001, respectively). EPMA investigations indicated that lime (CaO) was the dominant compound in NEC and MTA; however, other compounds were significantly different. It was concluded that the chemical composition of NEC is different compare with MTA; it can be concluded that the NEC exhibits acceptable physical properties. (J Endod 2008;34:990 -993)

Research paper thumbnail of Prevention and Inhibition of TC-1 Cell Growth in Tumor Bearing Mice by HPV16 E7 Protein in Fusion with Shiga Toxin B-Subunit from shigella dysenteriae

Cell journal, 2013

For immunotherapy of human papillomavirus (HPV) -16-associated cervical cancers the E7 protein is... more For immunotherapy of human papillomavirus (HPV) -16-associated cervical cancers the E7 protein is considered a prime candidate. However it is a poor inducer of cytotoxic T-cell response, when being used as a singular antigen in protein vaccination. Hence, in this study we focused on the utilization of a vaccine delivery system for prevention or treatment of cervical cancer. In this experimental study, we designed and evaluated a novel fusion protein comprising HPV16 E7 antigen fused to Shiga toxin B-subunit (STxB) as both an antigen vector and an adjuvant. Then we designed two preventive and therapeutic tumor models to investigate the prevention and inhibition of TC-1 cell growth in female C57BL/6 mice, respectively. In each model, mice were immunized with the recombinant protein of E7-STxB or E7 without any adjuvant. We demonstrated that prophylactic immunization of E7-STxB protected mice against TC-1 cells. Also in the therapeutic model, E7-STxB inhibited TC-1 tumor growth inlungs...

Research paper thumbnail of Removal of nitrogen and phosphorus from wastewater using microalgae free cells in bath culture system

Biocatalysis and Agricultural Biotechnology, 2014

ABSTRACT

Research paper thumbnail of Impacts of Amine Functionalized Iron Oxide Nanoparticles on HepG2 Cell Line

Current Nanoscience, 2014

ABSTRACT Iron oxide nanoparticles (IONs) are being used in medicine for magnetic resonance imagin... more ABSTRACT Iron oxide nanoparticles (IONs) are being used in medicine for magnetic resonance imaging, drug delivery and hyperthermia. There are contradictory data about cytotoxic effects of IONs on various cell lines. In this study a couple of IONs with two biocompatible coatings, L-lysine and 3-aminopropyltriethoxysilane, were synthesized by coprecipitation method in aqueous matrix and characterized. The MTT assay was used to evaluate the effects of the synthesised IONs on HepG2 cells. Cell culture illustrated that the growth of HepG2 cells can be promoted by IONs and nanoparticles with biocompatible coating have more biological benefit impacts than naked particles. By increase in concentration, cytotoxic effects will appear and reduce the growth promotion effects. Cytotoxic effects are in relation with agglomeration degree of nanoparticles, agglomeration can reduce cytotoxicity of IONs at high concentrations.

Research paper thumbnail of Chlorella vulgaris, a novel microalgal source for l-asparaginase production

Biocatalysis and Agricultural Biotechnology, 2014

ABSTRACT L-asparaginase is an amidohydrolase enzyme which is used for acute lymphoblastic leukemi... more ABSTRACT L-asparaginase is an amidohydrolase enzyme which is used for acute lymphoblastic leukemia chemotherapy. In this experiment we have collected 40 microalgal isolates from south of Iran. Intra and extra cellular L-asparaginase activity of these isolates were examined and the isolate with highest activity selected for molecular identification by 18S rDNA sequencing. A partial sequence of ~600 bp amplified and sequenced. The sequence similarity analyse is done using BLAST program from the National Centre for Biotechnology Information (NCBI) and there was 100% similarity with other reports for 18S rDNA sequences of Chlorella vulgaris. Also, GeneDoc software, version 2.6.002, was used for more 18S rDNA sequence investigation. We have found that Chlorella vulgaris can produce an inducible intracellular L-asparaginase in presence of L-asparagine, and L-asparagine can induce more growth of this microalga.

Research paper thumbnail of Modification in media composition to obtain secretory production of STxB-based vaccines using Escherichia coli

Virologica Sinica, 2013

Shiga toxin B-subunit (STxB) from Shigella dysenteriae targets in vivo antigen to cancer cells, d... more Shiga toxin B-subunit (STxB) from Shigella dysenteriae targets in vivo antigen to cancer cells, dendritic cells (DC) and B cells, which preferentially express the globotriaosylceramide (Gb3) receptor. This pivotal role has encouraged scientists to investigate fusing STxB with other clinical antigens. Due to the challenges of obtaining a functional soluble form of the recombinant STxB, such as formation of inclusion bodies during protein expression, scientists tend to combine STxB with vaccine candidates rather than using their genetically fused forms. In this work, we fused HPV16 E7 as a vaccine candidate to the recombinantly-produced STxB. To minimize the formation of inclusion bodies, we investigated a number of conditions during the expression procedure. Then various strategies were used in order to obtain high yield of soluble recombinant protein from E. coli which included the use of different host strains, reduction of cultivation temperature, as well as using different concentrations of IPTG and different additives (Glycin, Triton X-100, ZnCl 2 ). Our study demonstrated the importance of optimizing incubation parameters for recombinant protein expression in E. coli; also showed that the secretion production can be achieved over the course of a few hours when using additives such as glycine and Triton X-100. Interestingly, it was shown that when the culture mediums were supplemented by additives, there was an inverse ratio between time of induction (TOI) and the level of secreted protein at lower temperatures. This study determines the optimal conditions for high yield soluble E7-STxB expression and subsequently facilitates reaching a functionally soluble form of STxB-based vaccines, which can be considered as a potent vaccine candidate for cervical cancer.

Research paper thumbnail of Impacts of Iron Oxide Nanoparticles on the Invasion Power of Listeria monocytogenes

Current Nanoscience, 2014

ABSTRACT Recently, magnetic nanoparticles have been introduced as a novel antimicrobial material.... more ABSTRACT Recently, magnetic nanoparticles have been introduced as a novel antimicrobial material. Listeria monocytogenes are the causative agent of listeriosis and stands among the major public health issues. This bacterium can attach to the host cell membrane and trigger molecular responses leading to phagocytosis of the bacterial cell. In the present study, the effect of iron oxide nanoparticles (IONs) on the invasion power of L. monocytogenes was investigated. IONs were synthesized by coprecipitation method and coated with 3-aminopropyltriethoxysilane (APTES). Listeria monocytogenes cells were exposed to the prepared particles and interactions between IONs and bacterial cells were visualized by scanning electron microscopy. Invasion power of listerial cells for penetration HepG-2 cells monolayer was also examined in various concentrations of IONs. IONs have reduced invasion power of L. monocytogenes in a concentration-dependent manner. Almost 4-fold reduction in the invasion power of L. monocytogenes was observed at 20 µg ml-1 IONs concentration.

Research paper thumbnail of Biotransformation of monoterpenes by Oocystis pusilla

World Journal of Microbiology and Biotechnology, 2009

Abstract The biotransformation of several monoterpenes by the locally isolated unicellular microa... more Abstract The biotransformation of several monoterpenes by the locally isolated unicellular microalga, Oocystis pusilla was investigated. The metabolites were identified by thin layer chromatography and GC/MS. The results showed that O. pusilla had the ability to reduce the C=C double ...

Research paper thumbnail of ISOLATION, IDENTIFICATION, AND MEDIA OPTIMIZATION OF HIGH-LEVEL CELLULASE PRODUCTION BY Bacillus sp. BCCS A3, IN A FERMENTATION SYSTEM USING RESPONSE SURFACE METHODOLOGY

Preparative Biochemistry and Biotechnology, 2014

Cellulases are important glycosyl hydrolase enzymes, which break down cellulose to β-glucose. The... more Cellulases are important glycosyl hydrolase enzymes, which break down cellulose to β-glucose. They have been used widely in biotechnological processing such as bioethanol production. In this work we studied maximizing cellulase production by Bacillus sp. BCCS A3 using response surface methodology (RSM). A good result was attained with these conditions (% w/v): tryptone 0.1, Na₂PO₄ 0.25, (NH₄)₂SO₄ 0.2, MgSO₄ · 7H₂O 0.005, CaCl₂ 0.005, KH₂PO₄ 0.1, NaCl 0.1, sodium carboxymethylcellulose (CMC) 0.75, and pH 9. The cellulase activity in optimized medium was 49.80 U/ml. Moreover, high level of enzyme production was obtained by using fermentor system (50.30 U/ml). Thus, according to the obtained results, this statistical method provided quick identification and integration of key medium details for Bacillus sp. BCCS A3, leading to more cellulase production.

Research paper thumbnail of Characterization of Hydrocortisone Biometabolites and 18S rRNA Gene in Chlamydomonas reinhardtii Cultures

Molecules, 2008

A unicellular microalga, Chlamydomonas reinhardtii, was isolated from rice paddy-field soil and w... more A unicellular microalga, Chlamydomonas reinhardtii, was isolated from rice paddy-field soil and water samples and used in the biotransformation of hydrocortisone (1). This strain has not been previously tested for steroid bioconversion. Fermentation was carried out in BG-11 medium supplemented with 0.05% substrate at 25ºC for 14 days of incubation. The products obtained were chromatographically purified and characterized using spectroscopic methods. 11β,17β-Dihydroxyandrost-4-en-3-one (2), 11βhydroxyandrost-4-en-3,17-dione (3), 11β,17α,20β,21-tetrahydroxypregn-4-en-3-one (4) and prednisolone (5) were the main products of the bioconversion. The observed bioreaction features were the side chain degradation of the substrate to give compounds 2 and 3 and the 20-ketone reduction and 1,2-dehydrogenation affording compounds 4 and 5, respectively. A time course study showed the accumulation of product 2 from the second day of the fermentation and of compounds 3, 4 and 5 from the third day. All the metabolites reached their maximum concentration in seven days. Microalgal 18S rRNA gene was also amplified by PCR. PCR products were sequenced to confirm their authenticity as 18S rRNA gene of microalgae. The result of PCR blasted with other sequenced microalgae in NCBI showed 100% homology to the 18S small subunit rRNA of OPEN ACCESS Molecules 2008, 13 2417 two Chlamydomonas reinhardtii spp.

Research paper thumbnail of Isolation and characterization of some moderately halophilic bacteria with lipase activity

Research paper thumbnail of The Biotransformation, Biodegradation, and Bioremediation of Organic Compounds by MICROALGAE1

Journal of Phycology, 2011

Research paper thumbnail of Nucleophilic Substitution Reactions of Pyranose Polytosylates

The Journal of Organic Chemistry, 2004

Research paper thumbnail of A theory of mode of action of azolylalkylquinolines as DNA binding agents using automated flexible ligand docking

Journal of Molecular Graphics and Modelling, 2006

Azolylalkylquinolines (AAQs) are a family of quinolines with varying degrees of cytotoxic activit... more Azolylalkylquinolines (AAQs) are a family of quinolines with varying degrees of cytotoxic activity (comparable or moderately superior to adriamycin in some cases) developed in the past decade in our group where their exact mode of action is still unclear. In this study the most probable DNA binding mode of AAQs was investigated employing a novel flexible ligand docking approach by using AutoDock 3.0. Forty-nine AAQs with known experimental inhibitory activity were docked onto d(CGCAAATTTGCG) 2 , d(CGATCG) 2 and d(CGCG) 2 oligonucleotides retrieved from the Protein Data Bank (PDB IDs: 102D, 1D12 and 1D32, respectively) as the representatives of the three plausible models of interactions between chemotherapeutic agents and DNA (groove binding, groove binding plus intercalation and bisintercalation, respectively). Good correlation (r 2 = 0.64) between calculated binding energies and experimental inhibitory activities was obtained using groove binding plus intercalation model for phenyl-azolylalkylquinoline (PAAQ) series. Our findings show that the most probable mode of action of PAAQs as DNA binding agents is via intercalation of quinolinic moiety between CG base pairs with linker chain and azole moiety binding to the minor groove. #

Research paper thumbnail of Experimental design of medium optimization for invertase production by Pichia sp

Journal of Food Science and Technology, 2014

The culture medium requirement for invertase production by Pichia sp. was optimized and identifie... more The culture medium requirement for invertase production by Pichia sp. was optimized and identified by initial screening method of Plackett-Burman. Furthermore, optimum concentrations of medium components, which were selected by in initial screening by Plackett-Burman, were determined by the Box-Behnken and its representative three-factor response-surface method. The regression models showed significantly high R 2 values of 97% for invertase activities, indicating that they are appropriate for predicting relationships between yeast extract, peptone and sucrose concentration with invertase production. According to the model the optimal concentrations of sucrose, yeast extract and peptone were 40, 5 and 4 g/ml, respectively. These predicted conditions were verified by validation experiments. In the optimized medium Pichia sp. produced invertase with activity of 38.71 U/ml, which is 4 times higher than that produced in original medium. Thus, this statistical approach enabled rapid identification and integration of key medium parameters for Pichia sp. BCCS M1, resulted the high invertase production.

Research paper thumbnail of Round Cell Liposarcoma Metastatic to the Heart

Journal of Cardiac Surgery, 2013

Myxoid liposarcoma is a soft tissue tumor in adults with rare cardiac involvement. We report a 50... more Myxoid liposarcoma is a soft tissue tumor in adults with rare cardiac involvement. We report a 50-year-old female with high grade round cell liposarcoma of the left knee with metastases to the right heart chambers. The tumor was located in the right atrium with extension to right ventricle. The Patient underwent radiotherapy after surgical resection and 12-month follow-up revealed no recurrent cardiac disease.

Research paper thumbnail of Fatty acid evaluation in a naturally isolated strain of Chlorella vulgaris

Journal of Biotechnology, 2010

Research paper thumbnail of Cytotoxic and Apoptotic Effects of Three Types of Silver-Iron Oxide Binary Hybrid Nanoparticles

Current Pharmaceutical Biotechnology, 2016

Multifunctional nanostructures have received great deal of attention in biomedical area due to th... more Multifunctional nanostructures have received great deal of attention in biomedical area due to their capabilities in the development of new therapeutic and diagnostic agents. Silver and iron oxide nanoparticles, owing to their specific characteristics, are considered to develop bifunctional hybrid nanoparticles for magnetic delivery of silver nanoparticles as cytotoxic agent toward cancer cells. This study was designed to explore the in-vitro cytotoxic and apoptotic activities of three different silver-iron oxide binary hybrid nanoparticles on human liver hepatocellular carcinoma cell line. Three different silver-iron oxide binary hybrid nanoparticles were synthesized and characterized through the designed procedures. Apoptosis induction was investigated through flow cytometry and the influence on bax gene expression level was analyzed using quantitative real time polymerase chain reaction. All the three types of silver-iron oxide hybrid nanoparticles (possessing different characteristics) exhibited cytotoxic and apoptotic effects. Furthermore, the up regulation of bax gene expression suggested the involvement of the intrinsic pathway of apoptosis. Some of the transcription regulators which could interact with bax gene promoter were analyzed and found out to be mostly contributed in the stress responses. Among the test nanoparticles, the strongest cytotoxic and apoptotic effect was induced by the binary hybrid nanoparticle which was synthesized with glucose as reducing agent; suggesting that the biological activity was affected by different characteristics of the designed nanoparticles. Combined properties of silver and magnetic nanoparticles in the binary hybrid nanoparticles, provide a great potential to be exploited in the cancer therapy, where the combination of cytotoxicity and magnetic targeting is desired.

Research paper thumbnail of Comparative Study on Characteristics and Cytotoxicity of Bifunctional Magnetic-Silver Nanostructures: Synthesized Using Three Different Reducing Agents

Acta Metallurgica Sinica (English Letters), 2016

Research paper thumbnail of Isolation and Characterization of Some Moderately Halophilic Bacteria with Lipase Activity

Research paper thumbnail of The Properties of a New Endodontic Material

Journal of Endodontics, 2008

The purpose of this study was to analyze the physical properties and chemical compositions of a n... more The purpose of this study was to analyze the physical properties and chemical compositions of a new experimental cement (NEC) and compare them with mineral trioxide aggregate (MTA); pH, working time, setting time, dimensional changes following setting, flow, film thickness, and chemical composition of NEC and MTA were assessed. For chemical compositions, all specimens were imaged and analyzed by scanning electron microscopy and electron probe microanalysis (EPMA). The physical properties were performed according to ISO 6876:2001. Working time, pH, and dimensional changes of NEC and MTA showed similar results. Shorter setting time was obtained with the NEC compared with MTA (p Ͻ 0.05). The NEC showed more flow than MTA. In addition, the film thickness of the NEC was considerably less than the MTA (p Ͻ 0.01 and p Ͻ 0.001, respectively). EPMA investigations indicated that lime (CaO) was the dominant compound in NEC and MTA; however, other compounds were significantly different. It was concluded that the chemical composition of NEC is different compare with MTA; it can be concluded that the NEC exhibits acceptable physical properties. (J Endod 2008;34:990 -993)

Research paper thumbnail of Prevention and Inhibition of TC-1 Cell Growth in Tumor Bearing Mice by HPV16 E7 Protein in Fusion with Shiga Toxin B-Subunit from shigella dysenteriae

Cell journal, 2013

For immunotherapy of human papillomavirus (HPV) -16-associated cervical cancers the E7 protein is... more For immunotherapy of human papillomavirus (HPV) -16-associated cervical cancers the E7 protein is considered a prime candidate. However it is a poor inducer of cytotoxic T-cell response, when being used as a singular antigen in protein vaccination. Hence, in this study we focused on the utilization of a vaccine delivery system for prevention or treatment of cervical cancer. In this experimental study, we designed and evaluated a novel fusion protein comprising HPV16 E7 antigen fused to Shiga toxin B-subunit (STxB) as both an antigen vector and an adjuvant. Then we designed two preventive and therapeutic tumor models to investigate the prevention and inhibition of TC-1 cell growth in female C57BL/6 mice, respectively. In each model, mice were immunized with the recombinant protein of E7-STxB or E7 without any adjuvant. We demonstrated that prophylactic immunization of E7-STxB protected mice against TC-1 cells. Also in the therapeutic model, E7-STxB inhibited TC-1 tumor growth inlungs...

Research paper thumbnail of Removal of nitrogen and phosphorus from wastewater using microalgae free cells in bath culture system

Biocatalysis and Agricultural Biotechnology, 2014

ABSTRACT

Research paper thumbnail of Impacts of Amine Functionalized Iron Oxide Nanoparticles on HepG2 Cell Line

Current Nanoscience, 2014

ABSTRACT Iron oxide nanoparticles (IONs) are being used in medicine for magnetic resonance imagin... more ABSTRACT Iron oxide nanoparticles (IONs) are being used in medicine for magnetic resonance imaging, drug delivery and hyperthermia. There are contradictory data about cytotoxic effects of IONs on various cell lines. In this study a couple of IONs with two biocompatible coatings, L-lysine and 3-aminopropyltriethoxysilane, were synthesized by coprecipitation method in aqueous matrix and characterized. The MTT assay was used to evaluate the effects of the synthesised IONs on HepG2 cells. Cell culture illustrated that the growth of HepG2 cells can be promoted by IONs and nanoparticles with biocompatible coating have more biological benefit impacts than naked particles. By increase in concentration, cytotoxic effects will appear and reduce the growth promotion effects. Cytotoxic effects are in relation with agglomeration degree of nanoparticles, agglomeration can reduce cytotoxicity of IONs at high concentrations.

Research paper thumbnail of Chlorella vulgaris, a novel microalgal source for l-asparaginase production

Biocatalysis and Agricultural Biotechnology, 2014

ABSTRACT L-asparaginase is an amidohydrolase enzyme which is used for acute lymphoblastic leukemi... more ABSTRACT L-asparaginase is an amidohydrolase enzyme which is used for acute lymphoblastic leukemia chemotherapy. In this experiment we have collected 40 microalgal isolates from south of Iran. Intra and extra cellular L-asparaginase activity of these isolates were examined and the isolate with highest activity selected for molecular identification by 18S rDNA sequencing. A partial sequence of ~600 bp amplified and sequenced. The sequence similarity analyse is done using BLAST program from the National Centre for Biotechnology Information (NCBI) and there was 100% similarity with other reports for 18S rDNA sequences of Chlorella vulgaris. Also, GeneDoc software, version 2.6.002, was used for more 18S rDNA sequence investigation. We have found that Chlorella vulgaris can produce an inducible intracellular L-asparaginase in presence of L-asparagine, and L-asparagine can induce more growth of this microalga.

Research paper thumbnail of Modification in media composition to obtain secretory production of STxB-based vaccines using Escherichia coli

Virologica Sinica, 2013

Shiga toxin B-subunit (STxB) from Shigella dysenteriae targets in vivo antigen to cancer cells, d... more Shiga toxin B-subunit (STxB) from Shigella dysenteriae targets in vivo antigen to cancer cells, dendritic cells (DC) and B cells, which preferentially express the globotriaosylceramide (Gb3) receptor. This pivotal role has encouraged scientists to investigate fusing STxB with other clinical antigens. Due to the challenges of obtaining a functional soluble form of the recombinant STxB, such as formation of inclusion bodies during protein expression, scientists tend to combine STxB with vaccine candidates rather than using their genetically fused forms. In this work, we fused HPV16 E7 as a vaccine candidate to the recombinantly-produced STxB. To minimize the formation of inclusion bodies, we investigated a number of conditions during the expression procedure. Then various strategies were used in order to obtain high yield of soluble recombinant protein from E. coli which included the use of different host strains, reduction of cultivation temperature, as well as using different concentrations of IPTG and different additives (Glycin, Triton X-100, ZnCl 2 ). Our study demonstrated the importance of optimizing incubation parameters for recombinant protein expression in E. coli; also showed that the secretion production can be achieved over the course of a few hours when using additives such as glycine and Triton X-100. Interestingly, it was shown that when the culture mediums were supplemented by additives, there was an inverse ratio between time of induction (TOI) and the level of secreted protein at lower temperatures. This study determines the optimal conditions for high yield soluble E7-STxB expression and subsequently facilitates reaching a functionally soluble form of STxB-based vaccines, which can be considered as a potent vaccine candidate for cervical cancer.

Research paper thumbnail of Impacts of Iron Oxide Nanoparticles on the Invasion Power of Listeria monocytogenes

Current Nanoscience, 2014

ABSTRACT Recently, magnetic nanoparticles have been introduced as a novel antimicrobial material.... more ABSTRACT Recently, magnetic nanoparticles have been introduced as a novel antimicrobial material. Listeria monocytogenes are the causative agent of listeriosis and stands among the major public health issues. This bacterium can attach to the host cell membrane and trigger molecular responses leading to phagocytosis of the bacterial cell. In the present study, the effect of iron oxide nanoparticles (IONs) on the invasion power of L. monocytogenes was investigated. IONs were synthesized by coprecipitation method and coated with 3-aminopropyltriethoxysilane (APTES). Listeria monocytogenes cells were exposed to the prepared particles and interactions between IONs and bacterial cells were visualized by scanning electron microscopy. Invasion power of listerial cells for penetration HepG-2 cells monolayer was also examined in various concentrations of IONs. IONs have reduced invasion power of L. monocytogenes in a concentration-dependent manner. Almost 4-fold reduction in the invasion power of L. monocytogenes was observed at 20 µg ml-1 IONs concentration.

Research paper thumbnail of Biotransformation of monoterpenes by Oocystis pusilla

World Journal of Microbiology and Biotechnology, 2009

Abstract The biotransformation of several monoterpenes by the locally isolated unicellular microa... more Abstract The biotransformation of several monoterpenes by the locally isolated unicellular microalga, Oocystis pusilla was investigated. The metabolites were identified by thin layer chromatography and GC/MS. The results showed that O. pusilla had the ability to reduce the C=C double ...

Research paper thumbnail of ISOLATION, IDENTIFICATION, AND MEDIA OPTIMIZATION OF HIGH-LEVEL CELLULASE PRODUCTION BY Bacillus sp. BCCS A3, IN A FERMENTATION SYSTEM USING RESPONSE SURFACE METHODOLOGY

Preparative Biochemistry and Biotechnology, 2014

Cellulases are important glycosyl hydrolase enzymes, which break down cellulose to β-glucose. The... more Cellulases are important glycosyl hydrolase enzymes, which break down cellulose to β-glucose. They have been used widely in biotechnological processing such as bioethanol production. In this work we studied maximizing cellulase production by Bacillus sp. BCCS A3 using response surface methodology (RSM). A good result was attained with these conditions (% w/v): tryptone 0.1, Na₂PO₄ 0.25, (NH₄)₂SO₄ 0.2, MgSO₄ · 7H₂O 0.005, CaCl₂ 0.005, KH₂PO₄ 0.1, NaCl 0.1, sodium carboxymethylcellulose (CMC) 0.75, and pH 9. The cellulase activity in optimized medium was 49.80 U/ml. Moreover, high level of enzyme production was obtained by using fermentor system (50.30 U/ml). Thus, according to the obtained results, this statistical method provided quick identification and integration of key medium details for Bacillus sp. BCCS A3, leading to more cellulase production.

Research paper thumbnail of Characterization of Hydrocortisone Biometabolites and 18S rRNA Gene in Chlamydomonas reinhardtii Cultures

Molecules, 2008

A unicellular microalga, Chlamydomonas reinhardtii, was isolated from rice paddy-field soil and w... more A unicellular microalga, Chlamydomonas reinhardtii, was isolated from rice paddy-field soil and water samples and used in the biotransformation of hydrocortisone (1). This strain has not been previously tested for steroid bioconversion. Fermentation was carried out in BG-11 medium supplemented with 0.05% substrate at 25ºC for 14 days of incubation. The products obtained were chromatographically purified and characterized using spectroscopic methods. 11β,17β-Dihydroxyandrost-4-en-3-one (2), 11βhydroxyandrost-4-en-3,17-dione (3), 11β,17α,20β,21-tetrahydroxypregn-4-en-3-one (4) and prednisolone (5) were the main products of the bioconversion. The observed bioreaction features were the side chain degradation of the substrate to give compounds 2 and 3 and the 20-ketone reduction and 1,2-dehydrogenation affording compounds 4 and 5, respectively. A time course study showed the accumulation of product 2 from the second day of the fermentation and of compounds 3, 4 and 5 from the third day. All the metabolites reached their maximum concentration in seven days. Microalgal 18S rRNA gene was also amplified by PCR. PCR products were sequenced to confirm their authenticity as 18S rRNA gene of microalgae. The result of PCR blasted with other sequenced microalgae in NCBI showed 100% homology to the 18S small subunit rRNA of OPEN ACCESS Molecules 2008, 13 2417 two Chlamydomonas reinhardtii spp.

Research paper thumbnail of Isolation and characterization of some moderately halophilic bacteria with lipase activity

Research paper thumbnail of The Biotransformation, Biodegradation, and Bioremediation of Organic Compounds by MICROALGAE1

Journal of Phycology, 2011

Research paper thumbnail of Nucleophilic Substitution Reactions of Pyranose Polytosylates

The Journal of Organic Chemistry, 2004

Research paper thumbnail of A theory of mode of action of azolylalkylquinolines as DNA binding agents using automated flexible ligand docking

Journal of Molecular Graphics and Modelling, 2006

Azolylalkylquinolines (AAQs) are a family of quinolines with varying degrees of cytotoxic activit... more Azolylalkylquinolines (AAQs) are a family of quinolines with varying degrees of cytotoxic activity (comparable or moderately superior to adriamycin in some cases) developed in the past decade in our group where their exact mode of action is still unclear. In this study the most probable DNA binding mode of AAQs was investigated employing a novel flexible ligand docking approach by using AutoDock 3.0. Forty-nine AAQs with known experimental inhibitory activity were docked onto d(CGCAAATTTGCG) 2 , d(CGATCG) 2 and d(CGCG) 2 oligonucleotides retrieved from the Protein Data Bank (PDB IDs: 102D, 1D12 and 1D32, respectively) as the representatives of the three plausible models of interactions between chemotherapeutic agents and DNA (groove binding, groove binding plus intercalation and bisintercalation, respectively). Good correlation (r 2 = 0.64) between calculated binding energies and experimental inhibitory activities was obtained using groove binding plus intercalation model for phenyl-azolylalkylquinoline (PAAQ) series. Our findings show that the most probable mode of action of PAAQs as DNA binding agents is via intercalation of quinolinic moiety between CG base pairs with linker chain and azole moiety binding to the minor groove. #

Research paper thumbnail of Experimental design of medium optimization for invertase production by Pichia sp

Journal of Food Science and Technology, 2014

The culture medium requirement for invertase production by Pichia sp. was optimized and identifie... more The culture medium requirement for invertase production by Pichia sp. was optimized and identified by initial screening method of Plackett-Burman. Furthermore, optimum concentrations of medium components, which were selected by in initial screening by Plackett-Burman, were determined by the Box-Behnken and its representative three-factor response-surface method. The regression models showed significantly high R 2 values of 97% for invertase activities, indicating that they are appropriate for predicting relationships between yeast extract, peptone and sucrose concentration with invertase production. According to the model the optimal concentrations of sucrose, yeast extract and peptone were 40, 5 and 4 g/ml, respectively. These predicted conditions were verified by validation experiments. In the optimized medium Pichia sp. produced invertase with activity of 38.71 U/ml, which is 4 times higher than that produced in original medium. Thus, this statistical approach enabled rapid identification and integration of key medium parameters for Pichia sp. BCCS M1, resulted the high invertase production.

Research paper thumbnail of Round Cell Liposarcoma Metastatic to the Heart

Journal of Cardiac Surgery, 2013

Myxoid liposarcoma is a soft tissue tumor in adults with rare cardiac involvement. We report a 50... more Myxoid liposarcoma is a soft tissue tumor in adults with rare cardiac involvement. We report a 50-year-old female with high grade round cell liposarcoma of the left knee with metastases to the right heart chambers. The tumor was located in the right atrium with extension to right ventricle. The Patient underwent radiotherapy after surgical resection and 12-month follow-up revealed no recurrent cardiac disease.

Research paper thumbnail of Fatty acid evaluation in a naturally isolated strain of Chlorella vulgaris

Journal of Biotechnology, 2010