mohammad ali faramarzi

Carotenoids, such as β-carotene and astaxanthin, are the most important photosynthetic metabolites found in microalgae. They have several properties such as antioxidant and antidiabetic activities. β-Carotene is one of the precursors of vitamin A possessing useful applications in the food industry, cosmetics, and pharmaceuticals. The microalga Dunaliella salina is known as one of the biological producers of this valuable pigment, thanks to the lack of a rigid cell wall and shorter cultivation time. The optimization of culture medium for D. salina through the application of appropriate operational conditions such as static magnetic fields, can significantly impact biomass and carotenoids production. In this study, mixotrophic cultivation of D. salina was examined by adding different organic carbon sources, including glucose, fructose, acetate, malonate, glycerol, and starch, each at two levels of concentration. The inhibitory effect of malonate and glycerol on both growth and β-carotene production was observed. Starch demonstrated higher biomass production (1.22 g L−1) and β-carotene accumulation (10.12 mg L−1) compared to other carbon sources. Based on its superior performance, the optimization process was continued using 7.0 g L−1 of starch as the optimum concentration. Subsequently, static magnetic fields with two intensities (10 and 30 mT) were applied to the mixotrophic samples at various exposure times (1 and 24 h day−1). The results revealed that the 24-hour treatment with both intensities improved biomass production (2.18 g L−1) and β-carotene concentration (6 mg L−1) by up to 25% in the culture of D. salina enriched with an organic carbon source.

 Spirulina is a cyanobacteria species containing various bioactive compounds. Spirulina is a known source of nutrients in some traditional diets. Different activities have been reported for various extracts of S. platensis.

 In this study, the polysaccharide content of culture media and biomass extract of one species of Spirulina was partially purified, and its analgesic and anti-inflammatory effects were evaluated.

 Spirulina platensis PCST5 was cultured in a sterile Zarouk medium at 27°C and 16/8h of light/ dark exposure cycle for 25 days. Then, the polysaccharide content of biomass and cell-free culture medium samples (BPSs and CFPSs, respectively) was partially purified. The analgesic and anti-inflammatory effects were evaluated using animal models.

 16S rRNA gene analysis confirmed that the organism was genetically similar to Spirulina platensis. The CFPSs (30 and 100 mg/kg) and BPSs (30 mg/kg) significantly reduced pain-related behaviors in rats. Similarly, all samples could significantly reduce carrageenan-induced paw inflammation volume compared with the control group. Our results suggest Spirulina's polysaccharide fractions (CFPSs and BPSs) had significant analgesic and anti-inflammatory effects.

 Since Spirulina is a readily available source of bioactive compounds, finding such potent anti-inflammatory and anti-nociceptive compounds can provide promising leads for novel drug development.

The spread of drug resistance and limited effects of antibiotics on the pathogenic biofilms along with the increasing number of hospital infections have imposed heavy costs on the healthcare system. In the present study, quercetin-barium phosphate hybrid nanostructures were fabricated and characterized in order to improve their antibiofilm activity.

To prepare hybrid nanostructures, barium sulfate was added to sodium phosphate buffer containing quercetin (0.1 mg mL–1), the reaction mixture was sonicated for 10 min, and the obtained precipitate was collected. To obtain the hybrid nanostructures with the maximum immobilized quercetin, the concentrations of phosphate buffer and barium sulfate were examined in the range of 50–250 mM and 10–50 mM, respectively. The prepared hybrid nanostructures were characterized using scanning electron microscopy, infrared spectroscopy, and X-ray diffraction analysis, their effects were evaluated in preventing and destroying bacterial biofilms as well.

The immobilization yield of quercetin within hybrid structures was 95%. The scanning electron microscope images showed fiber-like structures with smooth, knot-free, and uniform surfaces. Quercetin-barium phosphate hybrid nanofibers significantly inhibited the biofilm formation in Pseudomonas aeruginosa and Staphylococcus aureus by 100% and 80%. Also, in the presence of the immobilized quercetin (500 mg L–1), biofilms of Staphylococcus aureus and Bacillus subtilis were destroyed by 75% and 70%.

Due to the notable antibiofilm properties of quercetin-barium phosphate hybrid nanofibers, they could be useful in medical devices, and therapeutic and environmental processes.

Organic-inorganic hybrid nanoflowers with flower-like morphology are new nanostructures comprising organic and inorganic components. In general, the organic component of hybrid nanoflowers mostly consists of proteins, DNA, RNA, plant extracts, metabolites, and natural polymers; and the inorganic component composes of various metal phosphates, including copper, calcium, manganese, iron, zinc, cobalt, cadmium, aluminum, silver, gold, etc. Until now, five notable procedures have been introduced for their synthesis, including biomineralization, ultra-fast sonication, the two-step method, shear stress, and the concentrated method. These nanostructures have many promising applications in diverse fields, such as the immobilization of enzymes and biomolecules, bio-catalysis of chemical reactions, bioremediation, electrochemical biosensors, drug and gene carriers, diagnosis of various diseases, photothermal therapy, etc., and wide range of research has been performed on them in the last recentdecade.Google Scholar, Scopus, ScienceDirect, and Springer databases were searched using the keywords hybrid nanostructure, nanoflower, biosciences, and biocatalyst to find related articles.Studying these organic-inorganic hybrid nanocrystals may lead to finding new creative solutions in the effective application of enzyme-based systems, the rapid development of bionanomaterials, and biotechnology industries. The present review has investigated the different types of hybrid nanoflowers, their synthesis procedures and structural characteristics, and their applications in biosciences.

Nowadays, magnetotactic bacteria have attracted the attention of scientists due to their green synthesis of nanoparticles. Magnetic nanoparticles enclose within the magnetosome; the bacterial intracellular organelle with a double-layered membrane which causes them to taxi the south and north poles of the earth. Bacteria synthesize magnetosomes in low oxygen conditions. Magneto-tactic bacteria are often isolated from the water sediments. All the magnetosome-forming bacteria are Gram-negative. Until now all of the identified Magnetotactic bacteria are among 13 phyla of 34 culturable phyla: Proteobacteria, Nitrospirota, Omnitrophota, Latescibacterota, Planctomycetota, Nitrospinota, Hydrogenedentota, Elusimicrobiota, Fibrobacterota, Riflebacteria, Bdellovibrionota, UBA1019, and desulfobacterota. The origin of magnetic behavior and magnetosome genes among all MTB is supposed to be acquired by horizontal gene transfer in different phyla. Magnetotactic bacteria have an -891gene core genome related to magnetotaxis named the magnetosome island. Some of the genes associated with proteins as Mam B, MamQ, MamT, MamM, MamK, and MamA (Mam: magnetosome membrane) are essential for magnetosome formation. Magnetosomes have various applications, such as sensing, diagnostics, remediation, immobilization of catalysts, and targeted delivery. Biosynthetic magnetite nanoparticles compared to those synthetic chemicals have exciting properties: they are permanently magnetic at room temperature, have high purity, and illustrate a uniform shape and size, low toxicity due to their membrane envelope, ferrimagnetic attributes, and dispersal capability, which are essential for their potential industrial applications. Due to the importance of magnetosomes in various applications and their unique characteristics, it is necessary to find and identify new sources and new bacteria

The oleoresin of Pistacia atlantica Desf. (known as “Baneh” in Iran) has been frequently used in traditional medicine for its medicinal properties. Herein, P. atlantica essential oil was investigated for its antimicrobial and α-glucosidase inhibitory activities since α-pinene which has been identified as the most abundant component in Pistacia genus oil, has demonstrated antimicrobial and anti-α-glucosidase properties. Fresh oleoresin was collected from Javanroud, Kermanshah, Iran and the essential oil was obtained by Clevenger-type apparatus. The chemical composition of essential oil was identified with GC/MS analysis and compared with those reported from various regions. The antimicrobial activity was evaluated against various strains (Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, Candida albicans, Saccharomyces cerevisiae, and Lactobacilli spp.) through MIC method. Also, its anti-α-glucosidase property and antioxidant activity by DPPH assay were investigated. GC/MS analysis of the essential oil confirmed the presence of nineteen compounds and among them, α-pinene (64.8%) was identified as the major constituent. Also, β-pinene (5.7%) and cis-limonene oxide (4.5%) were relatively abundant. Our results revealed antimicrobial properties of the “Baneh” essential oil against various bacterial and fungal strains. Moreover, it demonstrated inhibitory activity toward α-glucosidase with IC50 value of 41.5 ± 2.5 mg/mL compared with acarbose (IC50=0.5±0.2 mg/mL). DPPH free-radical scavenging activity assay showed antioxidant activity with IC50 value of 155.2 ± 1.4 mg/mL compared with quercetin (IC50=250.0±0.0 μg/mL). Pistacia atlantica oleoresin essential oil depicted satisfactory antimicrobial activity against both Gram-positive and Gram-negative strains. However, it demonstrated low antioxidant and α-glucosidase inhibitory effects.

Medicinal plants have been considered as important sources of potent free radical scavengers as well as digestive enzymes inhibitors. Several plants are used in traditional and modern medicine for their biological properties such as anti-oxidant and anti-diabetic activity. The aim of this study was to investigate the anti-diabetic and anti-oxidant activities of roots and aerial parts from three of five native Iranian herbaceaous Geum species, including G. iranicum, G. kokanicum and G. urbanum. The Geum species and their bio-active substances are getting a lot of attention due to their various biological effects, such as anti-oxidant, anti-diabetic, anti-tumor and anti-microbial activities.

The anti-diabetic activity of the Geum species was evaluated via α-glucosidase and α-amylase inhibition assays. The anti-oxidant effect was analyzed using the free radical scavenging method and the total phenolics content was determined via a colorimetric assay.

Based on our study, all the examined species revealed moderate to high anti-diabetic and anti-oxidant effects. Geum kokanicum roots showed the highest α-glucosidase inhibition activity (91.0%±1.7) at the concentration of 500 µg/mL and DPPH radical scavenging potential (IC50: 11.6±0.5 μg/mL).

The results demonstrated in-vitro anti-diabetic property of G. kokanicum, so detailed investigation to isolate the active compounds is suggested.

Polycyclic Aromatic Hydrocarbons (PAHs) as resistant compounds in the environment has received much attention in recent years due to their adverse effects on ecological health. Among the various methods studying the removal of PAHs, enzyme biotechnology is one of the most effective and appropriate method.  In the present study, a halophilic laccase was used for bioremoval of anthracene in the presence of 1-Hydroxybenzotriazole (HBT). Halophilic laccase from Alkalibacillus salilacus was tested for anthracene degradation. Residual concentration of anthracene at various concentrations of NaCl (0‒4 M), incubation time, pH, solvent, and surfactants in the enzymatic reaction mixtures was determined by HPLC. The maximum removal of substrate was achieved after 72 h at 40 °C, pH 8, and NaCl concentration 1.5 M. Besides, the addition of 1% (v/v) ionic and non-ionic surfactants and 25% (v/v) of various organic solvents increased removal efficiency. The kinetic parameters Km and Vmax of the laccase for removing of anthracene were 0.114 μM and 0.546 μmoL. h.−1 mg−1, respectively.  Laccase showed the maximum removal efficiency of anthracene in the presence of 1-Hydroxybenzotriazole (HBT).

In this study, we used a simple green method for preparing tellurium nanoparticles and mainly evaluated their toxicological effects. The nanoparticles were synthesized using lactose and characterized with different instrumentation methods. The in vitro and in vivo cytotoxicity of tellurium nanoparticles and its effect on lipid profile were also evaluated. Hydroxyl-capped tellurium nanoparticles were successfully fabricated by lactose. The results showed spherical tellurium nanoparticles with a mean size of 89 nm. The toxicological study showed that the tellurium nanoparticles did not exhibit any toxicity on the primary cells. The LD50 values for the nanoparticles were 327 and 295 mg/kg for oral and intraperitoneal administrations, respectively. Also, the results showed a significant reduction in liver enzymes at the 16, 24, and 40 mg/kg doses. Hematological parameters indicated no significant suppressive changes between the animals that were administered tellurium nanoparticles and the control group. In addition, the effects of tellurium nanoparticles on hypercholesterolemic risk factors in mice fed with cholesterol demonstrated the depletion of triglyceride, cholesterol, and low-density lipoprotein. This study showed that the toxicity of tellurium nanoparticles was lower than tellurium ions. Furthermore, tellurium nanoparticles decreased the cholesterol and triglyceride levels in the animal model.

Noscapine is an antispasmodic alkaloid used as antitussive and anti-cough obtained from plants in the Papaveraceae family which this benzylisoquinoline alkaloid and its synthetic subsidiaries (called noscapinoids) are being assessed for their anticancer potential.  The present research aimed to investigate the induction of DNA destruction and viability of HepG2 tumor spheroid culture influenced by noscapine and nanosuspension of noscapine. Culture of HepG2 cells as spheroids was treated with different concentrations of noscapine for 24 h on Day 11. Afterward, viability assay and alkaline comet assay methods were applied to examine the viability and induced DNA destruction, respectively. Based on the results, no significant impact was observed from Tween 40 on the viability and DNA damage levels in comparison with the control (p > 0.05). Moreover, increasing noscapine concentration resulted in a dose-dependent reduction in viability of hepatic cancer cells and elevation of DNA damages, showing a correlation between rises of DNA damages and viability decline.

Dorema ammoniacum </em>D. Don (Apiaceae family) is a perennial plant whose oleo-gum resin is used as a natural remedy for various diseases, especially chronic bronchitis, and asthma. In the present study, hydromethanolic extract of D. ammoniacum </em>root was subjected to phytochemical analyses and α-glucosidase inhibitory potentials of the isolated compounds were assessed.

Silica gel (normal and reversed phases) and Sephadex®</sup> LH-20 column chromatographies were used for the isolation and purification of the compounds. Structures of the compounds were characterized by 1D and 2D nuclear magnetic resonance (NMR) techniques. All the isolated compounds were assessed for their in vitro</em> α-glucosidase inhibitory activity in comparison with acarbose, a standard drug.

 Two phloroacetophenone glycosides; echisoside (1</strong>) and pleoside (2</strong>), along with dihydroferulic acid-4-O-β-D-glucopyranoside (3</strong>), and β-resorcylic acid (4</strong>), and two caffeoylquinic acid derivatives; chlorogenic acid (5</strong>) and 1, 5-dicaffeoylquinic acid (cynarin, 6</strong>) were isolated. </strong>Among the isolated compounds, the α-glucosidase inhibitory effect of 1,5-dicaffeoylquinic acid was found as 76.9% of the acarbose activity at 750 µM (IC50</sub> value of acarbose).

Considerable α-glucosidase inhibitory effect of 1,5-dicaffeoylquinic acid makes it an appropriate candidate for further studies in the development of new natural antidiabetic drugs.

Electrospray (Electrohydrodynamic atomization) has been introduced as a novel approach to prepare nanoparticles. This work aimed to prepare SLNs through electrospray and evaluate factors affecting particle size of prepared Solid Lipid Nanoparticles (SLNs).

SLNs were prepared by electrospray method. To study the factors affecting particle size of SLNs, Artificial Neural Networks (ANNs) were employed. Four input variables, namely, Tween 80 concentration, lipid concentration, flow rate, and polymer to lipid ratio were analyzed through ANNs and particle size was the output.

The analyzed model presented concentration of Tween 80 (surfactant) and lipid as effective parameters on particle size. By increasing surfactant and decreasing lipid concentration, minimum size could be obtained, while flow rate and polymer to lipid ratio appeared not to be effective.

Concentration of surfactant/lipid plays the most important role in determining the size.

It is well-known that the typical protein’s three-dimensional structure is relatively unstable in harsh conditions. A practical approach to maintain the folded state and thus improve the stability and activity of proteins in unusual circumstances is to directly apply stabilizing substances such as osmolytes to the protein-containing solutions. Osmolytes as natural occurring organic molecules typically called “compatible” solutes, based on the concept that they do not perturb cellular components. However, urea and guanidine hydrochloride (GuHCl) as denaturing osmolytes destabilize many macromolecular structures and inhibit functions. Several studies have been so far performed to explain the actual interaction of an osmolyte with a protein. The present review is aimed to achieve a collective knowledge of the progress arise in the field of osmolyte-protein interactions. The following is also an overview of the main techniques to measure protein stability in the presence of osmolytes.

Sustainable development in the bio-treatment of large-scale biomass bulks requires high performance enzymes adapted to extreme conditions. An extracellular keratinolytic extract was obtained from the culture broth of a halotolerant strain of Salicola marasensis. Keratin hydrolyzing activity of the concentrated enzyme extract was observed on a 100 mg of pretreated feather waste. The concentrated enzyme was able to hydrolyze the poultry feathers by 25% after 12 h incubation. The bio-waste material was optimally hydrolyzed at pH 9 and temperature of 40 °C. Among reductants, 1,4-dithiothreitol, L-cysteine, 2-mercaptoethanol, glutathione, and sodium sulfate showed the most remarkable effect on the bio-waste keratinolysis, while the tested surfactants and urea had no significant effect on the keratinolytic activity. Hexane and hexadecane indicated strong effect on keratinase activity and bio-treatment in the presence of 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF6]) as a hydrophobic ionic liquid resulted in a maximal of 80% extraction yield of soluble proteins from feathers. Considering the stability of the extracellular keratinolytic content in [BMIM][PF6], the observed keratinase activity was noteworthy suggesting that the secreted enzyme may contribute to the bioconversion of feather wastes.

Serralysin is an extracellular metalloprotease from Serratia marcescens which has been the subject of extensive biological investigations. The goal of this study was to extract and purify serralysin from S. marcescens and to investigate its cytotoxic activity on the colorectal cancer cell line.

The presence of the serralysin gene was confirmed using PCR. The supernatant of bacterial culture was collected and precipitated using ammonium sulfate. The precipitated protein was dialyzed and subjected to ion exchange chromatography for further purification. Casein assay and skim milk assay was used to confirm the enzymatic activity. SDS-PAGE was used to visualize the presence of serralysin. Metalloprotease inhibition activity was performed using 50 mM EDTA. Cytotoxic activity of serralysin was assessed on MTT assay.

The PCR product corresponding to serralysin was estimated to be approximately 1500 bp. A transparent zone around the bacterial colonies on skim milk agar and casein digestion confirmed the proteolytic activity of serralysin. A 52 kDa band in SDS-PAGE corresponding to serralysin was observed before and after purification processes. MTT assay showed IC50 values 24.78 μg/ml and 19.16 μg/ml after 24 h and 48 h exposure of Caco-2 cells to serralysin, respectively.

Our results showed that native serralysin has anticancer potential and may be a candidate for further pharmaceutical research and development. Further in vivo and in vitro mechanistic studies are suggested to confirm the biological activities.

In this study, in vitro inhibitory activity of methanolic and chloroform extracts of some medicinal plants including C. wightii, T. ammi, N. sativa, C. arabica, L. usitatissimum, C. cyminum, and R. Graveolens was evaluated toward α-glucosidase, α-amylase, and lipase comparing with acarbose and orlistat as the standard inhibitors. Our results revealed that both methanolic and chloroform extracts of C.wightii depicted high activity toward α-glucosidase (IC50s = 100.2 and 110.3 µg/mL, respectively) while methanolic and chloroform extracts of R.graveolens as well as chloroform extract of C.arabica showed good to moderate inhibitory activity (IC50s = 281.0, 460.5, and 280.0 µg/mL, respectively). Among the evaluated extracts, methanolic extract of R.graveolens and chloroform extract of C.arabica were found to be potent inhibitors toward α-amylase (IC50s = 215.0 and 180.0 µg/mL, respectively). However, moderate activity was obtained by methanolic and chloroform extracts of C. wightii and chloroform extract of R.graveolens (IC50 = 273.5, 358.5, and 479.0 µg/mL). It should be noted that all extracts demonstrated no significant inhibitory activity against lipase.

Dracocephalum species are mentioned in Iranian traditional medicine for enhancement of cognitive performance. In the present study, the acetyl cholinesterase inhibitory and butyryl cholinesterase inhibitory activities as well as the anti-oxidant and anti-tyrosinase effects of three Iranian Dracocephalum species (D. kotschyi, D. multicaule, D. polychaetum was analyzed).

The extractions were performed stepwise with hexane, chloroform, ethyl acetate (EtOAC), methanol (MeOH) and water. AChE and BChE inhibitory properties were measured by a microplate assay. Total phenolic content of all extracts were also evaluated and anti-oxidant activities of the extracts were assessed using DPPH, FRAP assays. Tyrosinase inhibitory activity was measured using the modified dopachrome method with L-DOPA as the substrate.

The results showed that the EtOAc extract of D. multicaule and MeOH extract of D. kotschyi were the most active anti-oxidant and anti-tyrosinase extracts which showed the highest amounts of phenolic compounds. Dracocephalum multicaule demonstrated the most considerable activity in AChE inhibition and D. polychaetum the highest activity in BChE inhibition. The aqueous extract of D. multicaule inhibited both AChE and BChE.

Dracocephalum multicaule can be suggested as a proper natural candidate for improvement of cognitive disorders.

Owing to their superior catalytic activity in the extreme conditions, extremozymes have found the potential biotechnological applications for industrial purposes. A robust extracellular protease activity was detected in the culture broth of Salicola marasensis, an extreme halophilic bacterium, after a 48 h-incubation. The effect of different media ingredients in a liquid state fermentation was followed with the aim of improving the enzyme production yield. Fractional factorial and Box-Behnken designs were applied to get a 3.4 fold (from 6.0 to 20.3 U mL−1) improvement of protease production. The distinguishing features of this enzyme were stability at a wide range of pH (5.0–11.0) and temperature (25–60 °C), significant compatibility towards organic solvents, metal ions, chemicals, and surfactants, and hydrolysis of a variety of substrates. The properties of this enzyme can be of tremendous help in terms of the halophilic proteolytic extract’s industrial applications.

Lipases are the biocatalysts with outstanding prospects in industry and medicine. They have proven to be useful in various hydrolytic and synthetic reactions. However, there are some limitations for impure lipases that may restrict their widely uses in industrial applications. Purification is sometimes vital for the characterization of the function, structure, and interactions of lipases. The lipase immobilization is also an efficient strategy for increasing the enzyme activity and stability, and getting a simpler recovery. Lipases are naturally produced together with many other proteins that they may occupy some surface of immobilization solid support and decrease the final activity. The coupling of immobilization and purification of lipase will overcome the mentioned problems and obtain the maximum purification yields. The present mini-review will discuss the use of the techniques that permit to join immobilization and purification of lipases in a single step, including control of the immobilization conditions by interfacial activation on hydrophobic supports, the development of specific supports with affinity for lipases, and the use of bio-affinity supports including immuno- and lectin affinity.

Molecular interactions are crucial between the enzyme molecules and the surrounding solution in an enzymatic catalysis. Although aqueous solutions used as conventional enzymatic reaction media, non-aqueous enzymology emerges as a major area of biotechnology research and development. Ionic liquids, as new generation of promising alternatives to traditional organic solvents, possess potential industrial enzymatic applications. Enzymes in ionic liquids present enhanced activity, stability, and selectivity. In addition, the potential of ionic liquids in bio-catalysis is raised by high ability of dissolving a wide variety of substrates and their extensively tunable solvent properties through appropriate modification of the cations and anions. However, despite the bio-friendly nature of ionic liquids for enzymatic reactions, their growing interests increase concerns associated with toxicity and environmental pollution of such compounds. This mini-review presents a brief highlight of the contemporary knowledge of enzymes activity and stability in ionic liquids and the environmental influences regarding the potential risks related to the growing applications of these green solvents.

Despite the progress in treatment of infectious diseases, ability of microorganisms to develop the resistance to routine antibiotics has still remained as a big global challenge in clinics. This subject matter keeps the infections top in the list of life threatening diseases especially in those individuals suffering from nosocomial infections. The importance of this global health challenge urges researchers to find an alternative solution with more efficacies to treat infections. There are some alternative approaches by which the global spread of resistant bacteria could be controlled. Through these ways, using bacteriophages instead of different generation of antibiotics brings many promises. According to results of different studies using bacteriophages in the management of infectious disease especially in nosocomial infections not only helps to reduce the spread of antibiotics resistance but also raises the hopes for the rescue of the suffering patients. Bacteriophages can open a new therapeutic window in the control and the treatment of the infectious disease with better efficacy.

Stereo-selectivity is an important feature in the development of the synthesis of biologically active organic compounds. In this process, (bio) catalysts exhibit substrate specificity that allows high levels of chemo- and regio-selectivity. Over the past decade, several peptides have been developed as effective bio-catalysts for a range of synthetically valuable reactions. In comparison with proteins owing a large number of amino acids and high molecular weights, peptide-catalysts possess only a few amino acid residues, which may adopt a secondary structure suitable for synthesis of desired chiral products. In addition, the flexible nature of peptides consents for tuning of reactivity and selectivity by replacing amino acid residues. These unique aspects provide attractive biocatalysts platform for asymmetric syntheses.

Size and size distribution of polymeric nanoparticles have important effect on their properties for pharmaceutical application. In this study, Chitosan nanoparticles were prepared by electrospray method (electrohydrodynamic atomization) and parameters that simultaneously affect size and/or size distribution of chitosan nanoparticles were optimized.
Effect of formulation/processing three independent formulation/processing parameters, namely concentration, flow rate and applied voltage was investigated on particle size and size distribution of generated nanoparticles using a Box–Behnken experimental design.
All the studied factors showed important effects on average size and size dis-tribution of nanoparticles. A decrease in size and size distribution was obtainable with decreasing flow rate and concentration and increasing applied voltage. Eventually, a sample with minimum size and polydispersity was obtained with polymer concentration, flow rate and applied voltage values of 0.5 %w/v, 0.05 ml/hr and 15 kV, respectively. The experimentally prepared nanoparticles, expected having lowest size and size distribution values had a size of 105 nm, size distribution of 36 and Zeta potential of 59.3 mV.
Results showed that optimum condition for production of chitosan nano-particles with the minimum size and narrow size distribution was a minimum value for flow rate and highest value for applied voltage along with an optimum chitosan concentration.

PLGA nanoparticles (NPs) have been extensively investigated as carriers of different drug molecules to enhance their therapeutic effects or preserve them from the aqueous environment. Streptokinase (SK) is an important medicine for thrombotic diseases.
In this study, we used electrospray to encapsulate SK in PLGA NPs and evaluate its activity. This is the first paper which investigates activity of an electrosprayed enzyme. Effect of three input parameters, namely, voltage, internal diameter of needle (nozzle) and concentration ratio of polymer to protein on size and size distribution (SD) of NPs was evaluated using artificial neural networks (ANNs). Optimizing the SD has been rarely reported so far in electrospray.
From the results, to obtain lowest size of nanoparticles, ratio of polymer/enzyme and needle internal diameter (ID) should be low. Also, minimum SD was obtainable at high values of voltage. The optimum preparation had mean (SD) size, encapsulation efficiency and loading capacity of 37 (12) nm, 90% and 8.2%, respectively. Nearly, 20% of SK was released in the first 30 minutes, followed by cumulative release of 41% during 72 h. Activity of the enzyme was also checked 30 min after preparation and 19.2% activity was shown.
Our study showed that electrospraying could be an interesting approach to encapsulate proteins/enzymes in polymeric nanoparticles. However, further works are required to assure maintaining the activity of the enzyme/protein after electrospray.