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Pseudomonas aeruginosa is one of the most important infectious pathogens in medicine. This bacterium causes various infections, especially in patients with severe burns and people with defective immune systems. The purpose of this study was to develop a nanovaccine based on PLGA nanoparticles and lipopolysaccharide and oligopolysaccharide antigens for appropriate stimulation of the humoral and cellular immune systems against P. aeruginosa. LPS-PLGA and OPS-PLGA conjugates were synthesized using the carbodiimide reaction. The prepared conjugates of as well as the pure antigens of LPS and OPS were injected to BALB/c mice in three periods at 2 week intervals. The ELISA test showed that the IgM, IgA, IgG, IgG1, IgG2b, IgG2a and IgG3 antibodies produced against LPS-PLGA or OPS-PLGA conjugates were tens of times higher than the pure antigens. Also, the opsonophagocytosis test showed that the performance and the effect of produced anti-LPS-PLGA antibodies were higher than other groups. In addition, the mice treated with LPS-PLGA conjugate were more resistant to P. aeruginosa infection than other groups. These findings indicated that LPS and OPS antigens in conjugation with PLGA nanoparticles have the ability to create and effective immunity against P. aeruginosa and LPS-PLGA is more effective than OPS-PLGA.

Methotrexate (MTX), as a folate antagonist is used for breast cancer chemotherapy, but its application due to the adverse side effects was limited. In this study, MTX were encapsulated in magnetic alginate beads coated with glutaraldehyde to control its release in order to reduce the side effects and improve its stability. The complex was characterized by physicochemical studies. The encapsulation efficiency was 75 % and the complex showed acceptable controlled release behavior. The cell cytotoxicity assessed using methylthiazol tetrazolium (MTT) method showed that magnetic alginate beads-MTX, in lower dosage has higher anticancer effect compared to the free MTX. The real-time polymerase chain reaction (PCR) was used to evaluate apoptotic factors Bcl

Staphylococcus aureus is an important infectious factor in the food industry and hospital infections. Many methods are used for detecting bacteria but they are mostly time-consuming, poorly sensiti...

Brucellosis is one of the most common and important diseases between humans and animals. Herein, we developed a nanovaccine against Brucella melitensis based on oligopolysaccharide (OPS) antigen and PLGA nanoparticles. The conjugation of extracted OPS with poly lactic-co-glycolic acid was performed. The antigenicity evaluation was conducted in 4 groups of 5 female BALB/c mice including OPS-PLGA conjugate, OPS alone, PLGA alone and PBS as a control. The mice were vaccinated intra-peritoneal three times with two-week intervals. To determine the immune response and functional capacity of the antibodies, the enzyme linked immunosorbent, opsonophagocytosis and challenge tests were performed. For checking the immunization ability of the nanovaccine, the challenge test was performed. The results showed a significant increase in the total IgG and IgM antibody titres in the mice vaccinated with OPS-PLGA conjugate in comparison with other groups. The sera of animals immunized with OPS-PLGA conjugate promoted efficient opsonophagocytosis of Brucella bacteria. The results of challenge assay showed that the immunization with OPS-PLGA conjugate gave a high level of protection in comparison with other groups. These findings showed that the new nanovaccine can be considered as a candidate for immunization of animals and humans against the diseases caused by B. melitensis that needs further investigations.

Purpose: Cancer is an example of the most important growing diseases in human society and scientists are trying to treat it without considerable side effects on patient’s health. Solid lipids are colloidal nanoparticles that were used in drug delivery due to their several advantages. Methods: In this work, surface modified targeted solid lipid nanoparticles (SLNs) were fabricated by nano-homogenizer using tripalmitin glyceride and stearic acid as lipid constituents. The size of nanoparticles and morphological evaluations were surveyed using particle size analyzer, scanning electron microscopy; Fourier transforms infrared spectroscopy (FT-IR) and differential scanning calorimetry (DSC). Results: The particle size of 148.5 and appropriate polydispersity index were achieved for lipid nanoparticles with an entrapment efficiency of 86.1%. The FT-IR analysis confirmed the coupling of lysine to the free functional group of SLNs. DSC proved the conjugation of amino acid to the surface of carriers. The in vitro epirubicin (EPI) release test exhibited the further controlled release phenomenon for the lysine conjugated nanoparticles. The cytotoxicity assay showed lower IC50 of lysine conjugated SLNs of EPI on the investigated cell line. Conclusion: These studies showed that the fabricated targeted carrier has a very remarkable anticancer effect on breast cancer cell lines in comparison with pure drug.

There is a big demand for fast, reliable, and low-cost systems for the detection, monitoring, and diagnosis of pollutant in the environment and agriculture. Quantitative analysis of environmental samples is usually carried out using traditional analytical methods such as chromatographic and spectroscopic techniques to identify various environmental contaminants. These methods, although accurate and sensitive, require sophisticated and expensive instrumentation, expert personnel for their operation, and multistep and complicated sample preparation. These techniques are also labor-intensive and time-consuming, and it is hard to monitor contaminants on site, in real time, and at high frequency. To overcome the issues associated with current diagnostic techniques, a wide range of new biosensors (an analytical device for the quantitative detection of analyte with a biologically active element) are being developed. Several of these biosensors rely on nanotechnological platforms. Hence, in this chapter, an emphasis has been given on the deployment of nanobiosensor in detection of pollutant in the environment.

Breast cancer is regarded as the most common cause of death after lung cancer among women. Using graphene quantum nanoparticles (GQNPs) to construct a biosensor increases the sensitivity, rapidness, and flexibility of biological tests to detect cancer cells. In this study, we developed a fluorescence immunosensor based on GQNPs and magnetic nanoparticles (MNPs) for selective detection of HER2-positive breast cancer. The GQNPs and MNPs were conjugated with Herceptin individually which was confirmed by physicochemical studies. Then, the conjugates were exposed to the SK-BR3 breast cancer cells to form a sandwich structure of MNP-Herceptin-SK-BR3 cell-Herceptin-GQNP. Then, an inverted fluorescence microscope was used to detect breast cancer cells after isolating them using a magnet. The results showed a high sensitivity (even one cell ml−1) and specificity of the designed biosensor for the detection of SK-BR3 cells within 30 min.

In recent years, the problems associated with bacterial resistance to antibiotics caused nanodrugs to be considered as a new way for infectious diseases treatment. The main purpose of this study was to develop a new agent against Pseudomonas aeruginosa, a very difficult bacterium to treat, based on azlocillin antibiotic and silver nanoparticles (AgNPs). Azlocillin was conjugated with AgNPs by chemical methods and its antimicrobial activity was studied against P. aeruginosa using well diffusion agar method. Then, minimum inhibitory concentration and minimum bactericidal concentration of the new conjugate was specified with macro-dilution method. The animal study showed the considerable enhanced antibacterial effect of azlocillin in conjugation with AgNPs against P. aeruginosa in comparison with azlocillin alone, AgNPs alone and azlocillin in combination with AgNPs.

Background: Feather waste is generated in large amounts as a by-product of commercial poultry processing. The main component of feather is keratin. The main purpose of this study was to identify Bacillus spp. (the keratinolytic bacteria) that are able to degrade the feather for producing keratin. Methods: Bacillus spp. Were isolated from the waste of poultries located in Miyaneh city. The bacteria were grown on basal medium containing 1% hen feather as the sole source of carbon ,nitrogen, sulfur and energy at 27ºC for 7 days. Then,the isolates capable of feather degrading were identified. The Bradford method was used to assay the production of keratin in the feather samples. Different pH and temperatures were studied to determine the best conditions for production of keratinase enzyme. Results: Seven Bacillus spp. including: B. pumilis, B. subtilis, B. firmus, B. macerance, B. popilliae, B. lentimorbus and B. larvae were found to be able to degrade the feather with different abilities. Conclusion: B. subtilis was found to be most productive isolate for keratinase enzyme production.

Nanotechnology deals with the production and usage of materials with nanoscale dimensions. The nanosized particles make an imprint in our daily lives and it has great importance in numerous fields of biotechnology, such as the food industry, medical, and industrial fields. Conventionally, metal nanoparticles are synthesized by chemical methods, which later on become accountable for various biological risks due to their general toxicity, engendering serious concern to develop environment-friendly processes. Green synthesis is the most fascinating, comparatively simple, and attractive alternative to chemical synthesis as it offers more advantages. The use of plant extracts for synthesis of NPs is potentially advantageous over microorganisms due to the ease of scaling up the biohazards and elaborates process of maintaining cell cultures. Nontoxic and ecofriendly secondary metabolites from plants are also used as reducing and capping agents. In this chapter, we provide comprehensive information about the current status of plant-mediated synthesis of metal nanoparticles, factors responsible for reduction of metal nanoparticle, and their applications.

P. aeruginosa is of particular importance due to its numerous pathogens and the spread of its multidrug-resistant strains around the world. Hence there is a need to develop an effective vaccine to prevent the diseases with P. aeruginosa. The aim of present study was to evaluate the immunogenicity of alginate (Alg) antigen in conjugation with SLN as a candidate for nanovaccine against P. aeruginosa in mouse model. Alginate is a weak immunogen, but the immune responses produced by alginate are effective in killing Pseudomonas bacteria. To increase the immunogenicity of alginate, SLN was used that is useful in drug delivery and can boost prolonged effectiveness. The results of ELISA and opsonophagocytosis tests showed that Alg-SLN conjugate has a better ability to stimulate the immune system to produce more immunoglobulins with better performance compared to alginate antigen alone. The challenge test also demonstrated that the Alg-SLN treated mice showed a higher level of immunity than the mice treated with pure alginate against infections caused by P. aeruginosa. Overally the findings showed the efficacy of new prepared vaccine to induce immunogenicity, and therefore it can be considered as a candidate for a strong vaccine against P. aeruginosa.

Biosynthesis of gold nanoparticles was investigated using Aspergillus flavus and the procedure was optimized for maximum production. The color changing from whitish-yellow to purple along with the maximum absorbance at 540 nm in UV-vis spectrum approved the production of gold nanoparticles preliminarily. The XRD spectrum of nanoparticles showed 2θ values corresponding to the gold nanocrystals. TEM micrographs demonstrated the extracellular formation of spherical gold nanoparticles. The optimization process revealed that the maximum rate of gold nanoparticles production achieved after 6 h at 28°C, 2.5 mM HAuCl4 concentration, and pH 6 with different shapes in the size range of 30–50 nm.

The risk of catching brucellosis and the absence of effective human vaccines has led to the use of new strategies to produce new vaccines against infections caused by this bacterium. In this study, the effect of two new designed nanovaccines on the production of immunoglobulins and their proper functions was investigated. Firstly, the production of immunoglobulins in the serum of the mouse model after three vaccination periods with lipopolysaccharide and oligopolysaccharide antigens in conjugation with PLGA nanoparticles were studied. The mice were divided into 6 groups and each group received LPS-PLGA, OPS-PLGA, LPS, OPS, PLGA and PBS separately. Immunoglobulin titers were measured every two weeks after each vaccination period. Two weeks after the last vaccination, opsonophagocytosis test were performed to evaluate the efficacy and function of produced immunoglobulins. In order to investigate the protective effect of nanovaccines in vivo, the mice were challenged with Brucella abortus bacteria. Immune responses have increased on immunoglobulin production after each vaccination period. The results of the opsonophagocytosis assay showed that produced immunoglobulins have the superior performance to antibodies produced against the pure antigens. By performing the challenge assay, it was found that the immune system of mice receiving new nanovaccines were able to remove more bacteria from the body of mice. In general, it can be concluded that both new prepared nanovaccines can be considered to improve the immunization process in animals and humans against brucellosis although LPS-PLGA conjugate creates more immunogenicity compared to OPS-PLGA nanovaccine.

Objective: To investigate the ability of Pseudomonas sp. isolated from East Azarbaijan, Iran in bioremediation of resorcinol. Methods: Resorcinol biodegradation was evaluated using spectrophotometry and confirmed by gas chromatography-mass spectroscopy. Results: This isolate was able to remove up to 37.12% of resorcinol from contaminated water. Reusability experiments had confirmed the biodegradation process which produced seven intermediate compounds. These intermediates were characterized by gas chromatographymass spectroscopy technique. The products of resorcinol biodegradation were apparently 1, 4-cyclohexadiene, nonadecene, 2-heptadecanone, 1-isopropyl-2-methoxy-4-methylbenzene, hexadecanoic acid, 9-octadecenoic acid, phenol and 5-methyl-2-(1-methylethyl). Conclusions: The findings revealed that Pseudomonas sp. is able to degrade resorcinol. Because of being an indigenous organism, this isolate is more compatible with the climate of the northwest region of Iran and possibly will be used for degradation of other similar aromatic compounds.

Staphylococcus aureus is a gram-positive and opportunistic pathogen that is one of the most common causes of nosocomial infections; therefore, its rapid diagnosis is important and valuable. Today, the use of nanoparticles is expanding due to their unique properties. The purpose of the present study is the determination of S. aureus by a colorimetric method based on gold nanoparticles (AuNPs). Firstly, S. aureus was cultured on both LB media (broth and agar) and their chromosomal DNA was extracted. Afterwards, primers and biosensor were designed based on Protein A sequence data in the gene bank. PCR assay was performed under optimal conditions and the PCR product was electrophoresed on 2-percent agarose gel. The synthesized biosensors were conjugated with AuNPs and, eventually, a single-stranded genome was added to the conjugated AuNPs and hybridization was performed. The results were evaluated based on color change detected by the naked eye, optical spectrophotometry, and transient electron microscopy. Finally, the sensitivity and specificity of the AuNP-biosensor were determined. The results of the present study showed a 390 bp band on the agarose electrophoresis gel, which confirmed the presence of Protein A genes on the chromosome of the bacteria. The PCR and colorimetric methods were compared with each other. The sensitivity of the PCR and colorimetric methods were 30 ng μL−1 and 10 ng μL−1, respectively. The limit of detection (LOD) equaling 8.73 ng μL−1 was determined and the specificity of the method was confirmed by the DNA of other bacteria. According to the results, the present method is rapid and sensitive in detecting S. aureus.

Due to the strong effect of nanoparticles' size and surface properties on cellular uptake and bio‐distribution, the selection of coating material for magnetic core–shell nanoparticles (CSNPs) is very important. In this study, the effects of four different biocompatible coating materials on the physical properties of Fe(3) O(4) (magnetite) nanoparticles (NPs) for different biomedical applications are investigated and compared. In this regard, magnetite NPs are prepared by a simple co‐precipitation method. Then, CSNPs including Fe(3) O(4) as a core and carbon, dextran, ZnO (zincite) and SiO(2) (silica) as different shells are synthesised using simple one‐ or two‐step methods. A comprehensive study is carried out on the prepared samples using X‐ray diffraction, vibrating sample magnetometry, transmission electron microscopy and Fourier transform infrared spectroscopy analyses. According to the authors' findings, it is suggested that carbon‐ and dextran‐coated magnetite NPs with high M (s) have great potential in the application of magnetic resonance imaging contrast agents. Moreover, silica‐coated magnetite NPs with high coercivity are potentially suitable candidates for hyperthermia and ZnO‐coated Fe(3) O(4) is potentially suitable for photothermal therapy.

Colorimetric DNA detection is preferred over other methods for clinical molecular diagnosis because it does not require expensive equipment. In the present study, the colorimetric method based on gold nanoparticles (GNPs) and endonuclease enzyme was used for the detection of P. aeruginosa ETA gene. Firstly, the primers and probe for P. aeruginosa exotoxin A (ETA) gene were designed and checked for specificity by the PCR method. Then, GNPs were synthesized using the citrate reduction method and conjugated with the prepared probe to develop the new nano-biosensor. Next, the extracted target DNA of the bacteria was added to GNP-probe complex to check its efficacy for P. aeruginosa ETA gene diagnosis. A decrease in absorbance was seen when GNP-probe-target DNA cleaved into the small fragments of BamHI endonuclease due to the weakened electrostatic interaction between GNPs and the shortened DNA. The right shift of the absorbance peak from 530 to 562nm occurred after adding the endonuclease. It was measured using a UV-VIS absorption spectroscopy that indicates the existence of the P. aeruginosa ETA gene. Sensitivity was determined in the presence of different concentrations of target DNA of P. aeruginosa. The results obtained from the optimized conditions showed that the absorbance value has linear correlation with concentration of target DNA (R: 0.9850) in the range of 10-50ngmL-1 with the limit detection of 9.899ngmL-1. Thus, the specificity of the new method for detection of P. aeruginosa was established in comparison with other bacteria. Additionally, the designed assay was quantitatively applied to detect the P. aeruginosa ETA gene from 103 to 108CFUmL-1 in real samples with a detection limit of 320CFUmL-1.

Fe3O4 (magnetite) nanoparticles (NPs) were synthesized using a co-precipitation method, and then annealed at various temperatures between 50 and 850 °C for 1 h in air. After annealing, the NPs were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy and vibrating sample magnetometer (VSM). The FTIR and XRD results indicated that Fe3O4 NPs were converted to γ-Fe2O3 (maghemite) by annealing at 250 °C for 1 h and then to α-Fe2O3 (hematite) on annealing in the range of 550–650 °C. The average crystallite size of the NPs estimated by the Debye–Scherrer equation increased from 6.6 to 37.6 nm by increasing annealing temperature from 50 to 850 °C. According to VSM results, the magnetite NPs were superparamagnetic and converted to the maghemite with superparamagnetic phase by annealing up to 550 °C. A phase transition from soft to hard ferromagnetic was occurred at annealing temperature 650 and 850 °C, respectively °C. This phase transition was attributed to the conversion of magnetite to hematite. The VSM analysis confirmed the XRD and FTIR results. The saturation magnetization (Ms) of Fe3O4 NPs was increased from 41.69 to 53.61 emu/g by increasing annealing temperature from 50 to 550 °C, and then decreased intensively to 0.49 emu/g after annealing at 850 °C. By increasing annealing temperature from 50 to 550, the crystallite size of NPs was increased from 6.6 to 12.7 and the coercive force (Hc) was reached to 4.20 Oe after annealing at 550 °C and then intensively increased to 1459.02 Oe for any further increasing of particle size up to 850 °C.

Fe3O4 nanoparticles were synthesized, using a simple co-precipitation method and then calcined at various temperatures in the range of 50–850 °C for 1 h in air. After calcination, the nanoparticles were characterized by X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy and vibrating sample magnetometer. The X-ray diffraction results indicated that Fe3O4 nanoparticles were converted to γ-Fe2O3 by calcining at 250 °C for 1 h and then to α-Fe2O3 on calcining in the range of 550–650 °C. The average crystallite size of the nanoparticles was calculated by using the Scherrer and Williamson-Hall methods. The average crystallite size of the iron oxides NPs increased from 7.2 to 35.8 nm by increasing calcination temperature from 50 to 850 °C. A small strain existed, which were affected on the physical and structural properties of Fe3O4. The vibrating sample magnetometer results indicated that, the as-synthesized nanoparticles converted from superparamagnetic to ferromagnetic phase with calcinations up to 650 °C, due to increasing size of nanoparticles from a single domain to multidomain as indicated in the X-ray diffraction results.

In this study, silver nanoparticles production was performed by the green chemistry the Zanjan gold mine. The formation of nanosilvers was primarily confirmed by observation of color changing from colorless to brownish and UV-visible spectroscopy after 72 h of the reaction. The XRD spectrum exhibited 2θ values corresponding to silver nanocrystals. TEM and SEM micrographs showed the extracellular formation of spherical silver nanoparticles in the size range of 30–150 nm by Penicillium chrysogenum and extracellular formation of cubical silver nanoparticles in the size range of 50–200 nm by Penicillium expansum.

The aim of this study was preparation and optimisation of a controlled-release delivery system to decrease the dose-dependent side effects of gentamicin. Hydrogel nanoparticles composed of a polycationic polymer (chitosan) and an inorganic polyanion (sodium tripolyphosphate) were fabricated in the presence of gentamicin. An experimental design was drawn upon to determine the optimum condition of nanoparticle preparation. Various features of the nanoparticles including drug loading parameters, particle size distribution, zeta potential and in vitro drug release profile were evaluated. Ultimately, the antimicrobial activity of the gentamicin-loaded nanoparticles was analysed by determination of the minimum inhibitory concentration (MIC) and the potency test. As a result, the nanocarriers with an average size of about 250 nm (unloaded) and 493 nm (gentamicin-loaded) were obtained with unimodal distribution and a notable polydispersity index (≤0.3). The drug loading efficiency was between 28 and 32%. The gradual and sustained releases (∼90%) of gentamicin were achieved in 24 h. The MIC and potency test showed no significant decrease in the antibacterial activity of gentamicin-loaded nanoparticles. The outcomes demonstrated that the optimised chitosan nanogels prepared in this study can be considered as a suitable carrier for a controlled release system.

Using of targeted contrast agents in X-ray imaging of breast cancer can improve the accuracy of diagnosis, staging, and treatment planning by providing early detection and superior definition of tumour volume. This study demonstrates a new class of X-ray contrast agents based on gold nanoparticles (GNPs) and bombesin (BBN) for imaging of breast cancer in radiology. GNPs were synthesised in spherical shape in the size range of 15 ± 2 nm and conjugated with BBN followed by coating with polyethyleneglycol (PEG). The in vitro and in vivo behaviour of PEG-coated GNPs-BBN conjugate was investigated performing cytotoxicity, binding, and internalisation assays as well as biodistribution and X-ray imaging studies in mouse bearing breast tumour. Cytotoxicity study showed biocompatibility of the prepared bioconjugate. The binding and internalisation studies using T47D cell line approved the targeting ability of new agent. The biodistribution study showed the considerable accumulation of prepared conjugate in breast tumour in mouse model. The breast tumour was clearly visualised in X-ray images taken from the mouse model. The results showed the potential of PEG-coated GNPs-BBN conjugate as a contrast agent in X-ray imaging of breast tumour in humans that need further investigations.

The field of nanotechnology is one of the most active areas of research in modern material sciences. Nanomaterials exhibit completely new or improved properties based on specific characteristics such as size, distribution, and morphology. At the present, there is an increasing commercial demand for nanostructures (nanoparticles and semiconductors) due to their wide applicability in various areas such as electronics, catalysis, chemistry, energy, and medicine. Biological synthesis of nanoparticles is a green route towards eco-friendly measures to overcome the toxicity and non-applicability of nanomaterials in clinical uses obtained by conventional physical and chemical approaches. A vast array of biological resources available in nature can be employed for synthesis of nanostructure materials including bacteria, fungi, yeasts, algae, and plants. However, owing to the rich biodiversity of biological systems, their potential for biosynthesis is yet to be fully explored. In this chapter, we provide comprehensive information about the current status of biological synthesis of metal and semiconductor nanomaterials, their applications, and scale-up.

99mTc-labeled antibiotics have opened an exciting field of research in infectious diseases diagnosis. Direct labeling of ceftriaxone with 99mTc was carried out using the various amounts of ceftriaxone and SnCl2·2H2O at different pH and incubation time intervals to find the highest radiochemistry efficiency with high stability at room temperature and human blood serum. ITLC-SG and HPLC were performed to measure the radiochemical purity of the conjugate. The binding study showed 45 % specific binding to Staphylococcus aureus. The biodistribution study and scintigraphic imaging showed the localization of 99mTc-ceftriaxone at the site of infection in comparison with normal and inflamed muscles with high sensitivity and specificity in mouse model. The results showed that 99mTc-ceftriaxone is a promising candidate as a targeting radiopharmaceutical for Staphylococcal infection imaging in humans which needs further investigations.

Bacteria have the most attendance in biosynthesis of silver nanoparticles either intra- or extracellular. In this study, we investigated biologic production of silver nanoparticles by a silver resistant Bacillus sp. isolated from a copper mine. The UV–vis and XRD spectra of the aqueous medium containing the Bacillus sp. and 3.5 mM AgNo3, showed the formation of silver nanoparticles. TEM and SEM micrographs showed extracellular synthesis of silver nanoparticles with spherical shape in the size range of 10–60 nm. Molecular study, performed based on the sequencing of 16S rRNA gene, demonstrated the strain of isolated Bacillus as megaterium.

There is no optimal imaging method for the detection of unknown infectious foci in some diseases. This study introduces a novel method in X-ray imaging of infection foci due to Staphylococcus aureus by developing a contrast agent based on gold nanoparticles (GNPs). GNPs in spherical shape were synthesised by the reduction of tetrachloroauric acid with sodium citrate. Then gentamicin was bound directly to citrate functionalised GNPs and the complex was stabilised by polyethylene glycol. The interaction of gentamicin with GNPs was confirmed by ultraviolet-visible and Fourier transform infrared spectroscopies. The stability of complex was studied in human blood up to 6 h. The stability of conjugate was found to be high in human blood with no aggregation. The biodistribution study showed localisation of gentamicin-GNPs conjugate at the site of Staphylococcal infection. The infection site was properly visualised in X-ray images in mouse model using the gentamicin-GNPs conjugate as a contrast agent. The results demonstrated that one may consider the potential of new nanodrug as a contrast agent for X-ray imaging of infection foci in human beings which needs more investigations.

Bio-barcode DNA based on gold nanoparticle (bDNA-GNPs) as a new generation of biosensor based detection tools, holds promise for biological science studies. They are of enormous importance in the emergence of rapid and sensitive procedures for detecting toxins of microorganisms. Exotoxin A (ETA) is the most toxic virulence factor of Pseudomonas aeruginosa. ETA has ADP-ribosylation activity and decisively affects the protein synthesis of the host cells. In the present study, we developed a fluorescence bio-barcode technology to trace P. aeruginosa ETA. The GNPs were coated with the first target-specific DNA probe 1 (1pDNA) and bio-barcode DNA, which acted as a signal reporter. The magnetic nanoparticles (MNPs) were coated with the second target-specific DNA probe 2 (2pDNA) that was able to recognize the other end of the target DNA. After binding the nanoparticles with the target DNA, the following sandwich structure was formed: MNP 2pDNA/tDNA/1pDNA-GNP-bDNA. After isolating the sandwiches by a magnetic field, the DNAs of the probes which have been hybridized to their complementary DNA, GNPs and MNPs, via the hydrogen, electrostatic and covalently bonds, were released from the sandwiches after dissolving in dithiothreitol solution (DTT 0.8 M). This bio-barcode DNA with known DNA sequence was then detected by fluorescence spectrophotometry. The findings showed that the new method has the advantages of fast, high sensitivity (the detection limit was 1.2 ng/ml), good selectivity, and wide linear range of 5–200 ng/ml. The regression analysis also showed that there was a good linear relationship (∆F=0.57 [target DNA]+21.31, R2=0.9984) between the fluorescent intensity and the target DNA concentration in the samples.

A stable, biocompatible and exquisite SPIONs-PEG-HER targeting complex was developed. Initially synthesized superparamagnetic iron oxide nanoparticles (SPIONs) were silanized using 3-aminopropyltrimethoxysilane (APS) as the coupling agent in order to allow the covalent bonding of polyethylene glycol (PEG) to the SPIONs to improve the biocompatibility of the SPIONs. SPIONs-PEG were then conjugated with herceptin (HER) to permit the SPIONs-PEG-HER to target the specific receptors expressed over the surface of the HER2+ metastatic breast cancer cells. Each preparation step was physico-chemically analyzed and characterized by a number of analytical methods including AAS, FTIR spectroscopy, XRD, FESEM, TEM, DLS and VSM. The biocompatibility of SPIONs-PEG-HER was evaluated in vitro on HSF-1184 (human skin fibroblast cells), SK-BR-3 (human breast cancer cells, HER+), MDA-MB-231 (human breast cancer cells, HER-) and MDA-MB-468 (human breast cancer cells, HER-) cell lines by performing MTT and trypan blue assays. The hemolysis analysis results of the SPIONs-PEG-HER and SPIONs-PEG did not indicate any sign of lysis while in contact with erythrocytes. Additionally, there were no morphological changes seen in RBCs after incubation with SPIONs-PEG-HER and SPIONs-PEG under a light microscope. The qualitative and quantitative in vitro targeting studies confirmed the high level of SPION-PEG-HER binding to SK-BR-3 (HER2+ metastatic breast cancer cells). Thus, the results reflected that the SPIONs-PEG-HER can be chosen as a favorable biomaterial for biomedical applications, chiefly magnetic hyperthermia, in the future.

Background: Wound infection is a common problem in hospitals and is typically caused by the antibiotic-resistant Staphylococcus aureus, which is a major pathogen for skin and soft tissue infections worldwide. Objectives: The aim of this study was to investigate the synergistic antibacterial effect of plant peptide MBP-1 and silver nanoparticles on infected wounds caused by S. aureus. Materials and Methods: The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of MBP-1 and silver nanoparticles both on their own and in combination form were determined against S. aureus via macrodilution and microdilution methods. The synergistic antibacterial effect of silver nanoparticles and MBP-1 was investigated on infected wounds caused by S. aureus in a mouse model. Results: The MIC and MBC of MBP-1 were found to be 0.6 and 0.7 mg/mL, respectively. MIC and MBC of silver nanoparticles were determined to be 6.25 and 12.5 mg/L, respectively. MIC and MBC of the silver nanoparticles and MBP-1 combination were found to be 3.125 mg/mL, 0.5 mg/L; and 6.25 mg/mL, 0.6 mg/L, respectively. The infected wound healed properly after the combined use of MBP-1 and silver nanoparticles. Conclusions: The synergistic effect was found on the healing of infected wounds caused by S. aureus by using an MBP-1 and silver nanoparticles combination in a mouse model.

The biosynthesis of gold nanoparticles would benefit from the development of clean, nontoxic, and environmentally acceptable procedures concerning microorganisms from bacteria to fungi. Streptomyces are saprophyte bacteria that have the enormous ability to produce secondary metabolites such as vitamin B, antibiotics, and antifungi. The authors investigated biosynthesis of gold nanoparticles by Streptomycec griseus. The UV–vis and XRD spectra of the aqueous medium containing Streptomycec griseus and 1 mM HAuCl4 demonstrated the formation of gold nanoparticles after 48 h. Transmission electron microscopy micrographs showed extracellular production of gold nanoparticles with good monodispersity, spherical shape, and average size of 50 nm.

In this study, we present a simple and eco-friendly method for extracellular biosynthesis of gold nanoparticles by Streptomyces sp. ERI-3 cell-free supernatant. The research was also aimed to evaluate the effects of different reaction parameters including incubation temperature, reaction time, HAuCl4 concentration and pH on gold nanoparticles production. The UV–Vis spectroscopy was used to monitor the formation of gold nanoparticles. The synthesized gold nanoparticles were characterized with XRD, TEM, and SEM. The average particle size ranged from 10 to 30 nm with spherical shape at optimum conditions.

Engineering of a physiologically compatible, stable and targetable SPIONs-CA-FA formulation was reported. Initially fabricated superparamagnetic iron oxide nanoparticles (SPIONs) were coated with citric acid (CA) to hamper agglomeration as well as to ameliorate biocompatibility. Folic acid (FA) as a targeting agent was then conjugated to the citric acid coated SPIONs (SPIONs-CA) for targeting the specific receptors expressed on the FAR+ cancer cells. Physiochemical characterizations were then performed to assure required properties like stability, size, phase purity, surface morphology, chemical integrity and magnetic properties. In vitro evaluations (MTT assay) were performed on HeLa, HSF 1184, MDA-MB-468 and MDA-MB-231cell lines to ensure the biocompatibility of SPIONs-CA-FA. There were no morphological changes and lysis in contact with erythrocytes recorded for SPIONs-CA-FA and SPIONs-CA. High level of SPIONs-CA-FA binding to FAR+ cell lines was assured via qualitative and quantitative in vitro binding studies. Hence, SPIONs-CA-FA was introduced as a promising tool for biomedical applications like magnetic hyperthermia and drug delivery. The in vitro findings presented in this study need to be compared with those of in vivo studies.

Gold nanoparticles exhibit unique optical, thermal, chemical and physical properties. The microorganisms have high potential for production of nanoparticles with wide applications. Application of fungi to produce nanoparticles is potentially exciting because of their ability to secrete large amounts of enzymes. In this study, we investigated biosynthesis of gold nanoparticles by the fungus Epicoccum nigrum isolated from Andalian gold mine in north-west of Iran. The gold nanoparticles were produced intra and extracellular by reaction of an aqueous solution of chloroauric acid with the biomass of fungus E. nigrum. The produced gold nanoparticles were in the size range of 5–50 nm in spherical and rod shapes. This is the first report on the biosynthesis of gold nanoparticles by the fungus E. nigrum.

PR81 is a monoclonal antibody that binds with high affinity to MUC1, which is over expressed on breast and other tumors. The objective of this study was to evaluate the application of this antibody against MUC1 as a radioimmunotherapeutical agent. Monoclonal antibody (PR81) against MUC1 was prepared, characterized, purified, and labeled with 131I. The immunoreactivity of radiolabeled mAb PR81with MUC1 (the native protein), BSA-P20 (a 20 amino acid corresponding the tandem repeat of MUC1) and MCF7 cell line were performed by RIA. In vitro stability of radiolabeled mAb in human serum was determined by thin layer chromatography (TLC). Cell toxicity and in vitro internalization studies were performed with the MCF7 cell line, and the tissue biodistribution of the radioiodinated PR81 was evaluated in normal BALB/c mice at 4, 24 and 48 hrs. The tumor imaging was performed in BALB/c mice with breast xenograft tumors at 24 and 72 hr after the complex injection. The labeling efficiency was found to be 59.9% ± 7.9%. MAb-131I conjugates showed high immunoreactivity towards MUC1 protein, BSA-P20 and MCF7 cell line. In vitro stability of the labeled product in human serum was found to be more than %50 over 24 hr. Cell toxicity and in vitro internalization studies showed that the mAb-131I conjugate inhibited 80% growth of the MCF7 cultured cell lines in vitro in a high concentration and up to %60 of the conjugate internalized after 24 h. Biodistribution studies were performed in normal BALB/c mice at 4, 24 and 48 hrs post-injection and no important accumulation was observed in vital organs. The tumors were visualized with high sensitivity after 24 and 72 hr in radioimmunoscintographical studies. These results show that the new radiopharmaceutical may be considered as a promising candidate for therapy of breast cancer.

PR81 is a monoclonal antibody that binds with high affinity to MUC1, which is over expressed on breast and other tumors. The objective of this study was to compare the two labeling methods (direct and indirect radioiodination) for application of this antibody against MUC1 as a radioimmunotherapeutical agent.Monoclonal antibody (PR81) against the tandem repeat of the core protein (MUC1) was prepared, characterized, purified, and labeled with 131I using the direct (chloramin-T) and indirect (Fmoc-D-Tyr (tBu)-D-Tyr (tBu)-D-Lys (Boc)-OH (YYK) attached to N-hydroxysuccinimide as a linker between PR81 and 131I) methods. The immunoreactivity of 131I-PR81 and 131I-TP-PR81 complexes with MUC1 (the native protein), BSA-P20 (a 20 amino acid corresponding the tandem repeat of MUC1) and MCF7 cell line were performed by RIA. In vitro stability of 131I-PR81 and 131I-YYK-peptide-PR81 complexes in human serum was determined by thin layer chromatography (TLC). Cell toxicity and in vitro internalization studies were performed with the MCF7 cell line, and the tissue biodistribution of the 131I-PR81 and 131I- YYK-peptide -PR81 complexes was evaluated in normal BALB/c mice at 4, 24 and 48 hrs. The labeling efficiency was determined by measuring the percentage recovery of radioactivity in the final product relative to the initial activity in the shipment vial, was found to be 59.9% +/- 7.9% for direct and 50% +/- 3.2% for indirect methods. 131I-PR81 and 131I- YYK- peptide -PR81 complexes showed high immunoreactivity towards MUC1 protein, BSA-P20 and MCF7 cell line. In vitro stability of the labeled products in human serum which was measured by thin layer chromatography (TLC) was found to be more than 50% over 24 hr for 131I-PR81 and 70% for 131I- YYK-peptide -PR81 complexes. Cell toxicity and in vitro internalization studies showed that the 131I-PR81 and 131I- YYK-peptide -PR81 complexes inhibited 80% growth of the MCF7 cultured cell lines in vitro in a high concentration and up to 40% of the 131I-PR81 and 60% of the 131I- YYK-peptide -PR81 complexes internalized after 24 h. Biodistribution studies were performed in normal BALB/c mice at 4, 24 and 48 hrs post-injection. Thyroid and stomach levels from PR81 labeled with 131I- YYK-peptide were two- to three- fold less than those with directly labeled 131I-PR81, suggesting low recognition of its D-iodotyrosine residue by endogenous deiodinase. These results show that the indirect labeling was better than the indirect labeling and 131I- YYK-peptide -PR81 may be considered as a promising candidate for therapy of breast cancer.