Curcumin Mediated Gold Nanoparticles and Analysis of its Antioxidant, Anti-inflammatory, Antimicrobial Activity Against Oral Pathogens

ABSTRACT Objective: To green synthesise gold nanoparticles using curcumin and to analyse its antioxidant, anti-inflammatory, and antimicrobial activity among oral pathogens. Material and Methods: Biosynthesised Curcumin Gold nanoparticles (CuAuNP) were evaluated by UV-visible spectrophotometer (UV-Vis), Transmission Electron Microscopy (TEM), and evaluation of antioxidant, anti-inflammatory and antibacterial activity against oral pathogens. Results: Synthesized CuAuNP were characterized using UV-visible spectrophotometry and showed peak absorption at 530nm. CuAuNp showed a 90.3% maximum scavenging ability of DPPH at a concentration of 50 μg/mL. CuAuNP exhibited 79.6 % of the highest anti-inflammatory activity at 50μg/mL than the standard drug diclofenac. TEM image clearly showed uniformly dispersed spherical-shaped gold nanoparticles with a size of about 20 nm. The biosynthesized nanoparticle was tested for its antimicrobial effect, and it showed a potent effect against S. aureus, E. faecalis, and C. albicans at 100µg/ mL. Enterococcus faecalis has a maximum zone of inhibition of 14 mm at 100µg/ mL of CuAuNp. Among gram-positive bacteria, a maximum zone of inhibition of 12 mm at 100µg/ mL was seen in S. aureus compared to S mutans. Candida albicans showed a maximum zone of inhibition of 18 mm at 25 μg/mL of CuAuNp. Conclusion: Curcumin-mediated gold nanoparticles with 20 nm size were effective and had strong antioxidant and anti-inflammatory activity at 50µg/ mL, antimicrobial action inhibiting microbes at 100µg/mL concentration that can be used in treating various Oral mucosal lesions.

Role of biologically synthesised nanoparticles in environmental pollution remediation

Environmental pollution is serious threat for all living organisms. Nanoparticle synthesis using green approach is a non-toxic, easy and energy saving process. Varieties of species have the unique capability to synthesize commercially useful nanoparticles from various metal salt precursors that can help in environmental remediation. The combination of nanotechnology and bioremediation is known as Nanobioremediation. Researchers have shown that biologically nanoparticles shows great potential in reducing environmental pollution from water and soil by adsorption of pollutants and harmful toxic substances from their environment .These green nanoparticles can convert toxic chemicals into less toxic form. Studies also shown that metal nanoparticles also help in removal of harmful bacteria and fungi from environment which can cause diseases in living system. Green synthesised nanoparticles shows very promising results when it comes to environmental remediation they have been used as dye degrader,Oil degrader, photocatalytic agents, biosensors, heavy metals and persidtent organic particulate (POPs) absorbers etc. This review focus on the current status of different types of biologically synthesised nanoparticles in environmental pollution from different species and future challenges associated with environmental remediation.

Evaluation of antibacterial properties and shear bond strength of orthodontic composites containing silver nanoparticles, titanium dioxide nanoparticles and fluoride: An in vitro study

ABSTRACT Objective: The study aimed at determining the antibacterial properties of composites containing silver nanoparticles (Ag NPs) or titanium dioxide nanoparticles (TiO2 NPs), and a fluoride-releasing composite against Streptococcus mutans and Lactobacillus acidophilus, and to evaluate the effect on shear bond strength (SBS) of nanoparticles-modified composites. Materials and Methods: An orthodontic composite was modified by adding 1% w/w Ag NPs or 1% w/w TiO2 NPs. Composite discs were prepared to evaluate the antibacterial properties of these modified composites against Streptococcus mutans and Lactobacillus acidophilus, using three different antibacterial tests, namely: Disk agar diffusion test, Biofilm inhibition test and eluted component test. For evaluating the shear bond strength, 80 extracted premolars were collected and divided into four groups (n=20 each), which were bonded with stainless steel preadjusted Edgewise brackets, by using these modified composites. Their SBS was then compared with that of the control group, using a universal testing machine. Results: Composite discs containing nanoparticles and fluoride were capable of producing growth inhibition zones for all bacterial types. Results of the biofilm inhibition test showed that all the study groups inhibited the bacterial count, in comparison to the control group. A significant difference of SBS was observed between all groups. Conclusion: The antibacterial activity of orthodontic composites modified with Ag and TiO2 nanoparticles was significant, compared with conventional and fluoride-containing composites. The control group showed the highest SBS, followed by fluoride, titanium, and silver groups, with statistically significant difference in mean SBS values among all groups.

RESUMO Objetivo: O objetivo do presente estudo foi determinar a eficácia das propriedades antibacterianas de compósitos contendo nanopartículas de prata (Ag NPs) ou nanopartículas de dióxido de titânio (TiO2 NPs) e de um compósito com liberação de flúor, contra as bactérias Streptococcus mutans e Lactobacillus acidophilus e, também, avaliar o efeito na resistência ao cisalhamento (RC) desses compósitos modificados com nanopartículas. Métodos: Os compósitos ortodônticos foram modificados pela adição de 1% p/p de Ag NPs e 1% p/p de TiO2 NPs. Discos de compósito foram preparados para avaliar as propriedades antibacterianas desses grupos contra as bactérias Streptococcus mutans e Lactobacillus acidophilus, usando três testes antibacterianos diferentes: teste de disco-difusão em ágar, teste de inibição da formação de biofilme e teste de componentes eluídos. Para avaliar a resistência ao cisalhamento dos compósitos, 80 pré-molares extraídos foram coletados e divididos em quatro grupos, contendo 20 dentes cada. Foram utilizados braquetes Edgewise pré-ajustados de aço inoxidável para colagem nos dentes usando as resinas modificadas. A RC desses compósitos modificados foi comparada à dos grupos controle, usando uma máquina universal de testes. Resultados: Os discos de compósito contendo as nanopartículas e flúor foram capazes de produzir halos de inibição de crescimento para todos os tipos de bactérias. Os resultados do teste de inibição do biofilme mostraram que houve uma redução na contagem de bactérias em relação ao grupo controle. Diferenças significativas na RC foram observadas entre todos os grupos. Conclusão: A atividade antibacteriana dos compósitos ortodônticos modificados com nanopartículas de Ag e TiO2 foi significativa, quando comparada ao compósito convencional e ao compósito com flúor. O grupo controle apresentou a maior RC, seguido pelos grupos Flúor, Titânio e Prata, com diferença estatisticamente significativa nos valores médios da RC entre todos os grupos.

Antibacterial effect of titanium alloys with copper nanoparticles: in vitro study

Objective: To evaluate the in-vitro antimicrobial effect of Titanium alloys with Copper Nanoparticles (CuNP) against Streptococcus mutans and Phorphyromonas gingivalis. Materials and Methods: An in vitro study was carried out. The unit of analysis corresponded to 10 healing abutments. In 5 abutments Copper nanoparticles (CuNP) electrodeposition was applied. The remaining 5 abutments corresponded to control. The healing abutments were then immersed in culture medium for S. mutans and P. gingivalis for 14 days. Results: The agar plates with CuNP-coated abutments showed a lower growth, statistically significant for both bacterial strains. Conclusion: There is a statistically significant lower growth of S. mutans and P. gingivalis in healing abutments with CuNP.

The effectiveness of heparin, platelet-rich plasma (PRP), and silver nanoparticles on prevention of postoperative peritoneal adhesion formation in rats

Abstract Purpose: To assess the effectiveness of heparin, platelet-rich plasma (PRP), and silver nanoparticles on prevention of postoperative adhesion in animal models. Methods: Sixty males Albino Wistar rats aged 5 to 6 weeks were classified into five groups receiving none, heparin, PRP, silver nanoparticles, PRP plus silver nanoparticles intraperitoneally. After 2 weeks, the animals underwent laparotomy and the damaged site was assessed for peritoneal adhesions severity. Results: The mean severity scores were 2.5 ± 0.9, 2.16 ± 0.7, 1.5 ± 0.5, 2.66 ± 0.88, and 2.25 ± 0.62 in the control, heparin, PRP, silver and PRP plus silver groups, respectively with significant intergroup difference (p = 0.004). The highest effective material for preventing adhesion formation was PRP followed by heparin and PRP plus silver. Moreover, compared to the controls, only use of PRP was significantly effective, in terms of adhesion severity (p = 0.01) . Conclusion: Platelet-rich plasma alone may have the highest efficacy for preventing postoperative peritoneal adhesions in comparison with heparin, silver nanoparticles and PRP plus silver nanoparticles.

The effectiveness of heparin, platelet-rich plasma (PRP), and silver nanoparticles on prevention of postoperative peritoneal adhesion formation in rats

Purpose: To assess the effectiveness of heparin, platelet-rich plasma (PRP), and silver nanoparticles on prevention of postoperative adhesion in animal models. Methods: Sixty males Albino Wistar rats aged 5 to 6 weeks were classified into five groups receiving none, heparin, PRP, silver nanoparticles, PRP plus silver nanoparticles intraperitoneally. After 2 weeks, the animals underwent laparotomy and the damaged site was assessed for peritoneal adhesions severity. Results: The mean severity scores were 2.5 ± 0.9, 2.16 ± 0.7, 1.5 ± 0.5, 2.66 ± 0.88, and 2.25 ± 0.62 in the control, heparin, PRP, silver and PRP plus silver groups, respectively with significant intergroup difference (p = 0.004). The highest effective material for preventing adhesion formation was PRP followed by heparin and PRP plus silver. Moreover, compared to the controls, only use of PRP was significantly effective, in terms of adhesion severity (p = 0.01) . Conclusion: Platelet-rich plasma alone may have the highest efficacy for preventing postoperative peritoneal adhesions in comparison with heparin, silver nanoparticles and PRP plus silver nanoparticles.

Effect of silver nanoparticles on the physicochemical and antimicrobial properties of an orthodontic adhesive

ABSTRACT Orthodontic treatment with fixed brackets plays a major role on the formation of white spot lesions. Objective This study aimed to incorporate silver nanoparticle solutions (AgNP) in an orthodontic adhesive and evaluate its physicochemical and antimicrobial properties. Material and Methods Silver nanoparticle solutions were added to a commercial adhesive in different concentrations (w/w): 0%, 0.11%, 0.18%, and 0.33%. Shear bond strength (SBS) test was performed after bonding metal brackets to enamel. Raman spectroscopy was used to analyze in situ the degree of conversion (DC) of the adhesive layer. The surface free energy (SFE) was evaluated after the measurement of contact angles. Growth inhibition of Streptococcus mutans in liquid and solid media was determined by colony-forming unit count and inhibition halo, respectively. One-way ANOVA was performed for SBS, DC, SFE, and growth inhibition. Results The incorporation of AgNP solution decreased the SBS (p<0.001) and DC in situ (p<0.001) values. SFE decreased after addition of 0.18% and 0.33% AgNP. Growth inhibition of S. mutans in liquid media was obtained after silver addition (p<0.05). Conclusions The addition of AgNP solutions to Transbond™ XT adhesive primer inhibited S. mutans growth. SBS, DC, and SFE values decreased after incorporation up to 0.33% AgNP solution without compromising the chemical and physical properties of the adhesive.

Purification of carbon monoxide in armored vehicle cabins / 军事医学

Objective To study a purification prototype with a noble metal nano catalyst as the main material in order to improve the combat capability of the crew of armored vehides.Methods At natural temperature, the single way purification experiment, static and dynamic purification experiments were carried out in the 1 m3 and the 7 m3 cabins. Results In the single way purification experiment, the prototype kept the purification rate above 40%and 50%when the CO concentration was below 800 mg/m3 and the air flow rate was 1 and 2 m3/min.During static experiments, the CO purification rate was 90% at the initial concentration of 800 mg/m3 and after 3′43″and 20′.During the dynamic experiment, the average elevation rate of the gas concentration was significantly lower than that of the control experiment. Conclusion In a natural environment, the prototype can effectively purify CO gas.Key technology of CO gas purification has been made available that can be used to develop CO gas purification devices in armored vehicles.

Pure magnesium micro-arc oxidation coating containing nano-SiO2 or nano-TiO2 promotes proliferation and viability of osteoblasts / 中国组织工程研究

BACKGROUND:The micro-arc oxidation technology can enhance the corrosion resistance of magnesium and its aloys to improve the biological properties of the surface. OBJECTIVE: In order to regulate the biological activity of medical pure magnesium, to modify the micro-arc oxidation coating by adding nano-SiO2 and nano-TiO2 into the plating solution, and to study the biological coating effects on osteoblast proliferation and differentiation. METHODS: Round magnesium sheets were divided into three groups, respectively treated with silicate electrolyte containing 7.5 g/L nano-SiO2 (nano-SiO2 group), 4.8 g/L nano-TiO2 (nano-TiO2 group), and nothing (control group). Passage 3 osteoblasts were seeded onto the specimen surface in the three groups to observe the early morphology, proliferation and alkaline phosphatase activity of osteoblasts. RESULTS AND CONCLUSION:Osteoblasts grew wel in the nano-SiO2 group and nano-TiO2 group, presenting with clear outline, and the cels were long spindle- and polygon-shaped. But in the control group, the cels grew poor in the specimen surface. Cel counting kit-8 test showed that the absorbance values and alkaline phosphatase activities were increased with time in the three groups. Compared with the control group, the proliferative activity was higher in the nano-SiO2 group and nano-TiO2 group at days 1, 3, 5 after seeding, while the activity of alkaline phosphatase was also higher in the nano-SiO2 group and nano-TiO2 group at days 3, 5 after seeding. These findings indicate the micro-arc oxidation coatings containing nano-SiO2and nano-TiO2 can promote osteoblast proliferation and osteogenetic activity, which have good biocompatibility.

Avaliação de propriedades físico-químicas, mecânicas e antimicrobianos do MTA e cimento Portland associado a solução de nanopartículas de prata / Evaluation of physico-chemical, mechanical and antimicrobial properties of MTA and Portland cement associated with silver nanoparticles solution

A substituição do óxido de bismuto por óxido de zircônio (ZrO2) e a adição de nanopartículas de prata (NPsAg) pode favorecer as propriedades físico-químicas mecânicas e antimicrobianas. Capítulo 1: Foram avaliados pH, solubilidade, tempo de presa, radiopacidade e resistência à compressão. Grupos: G1 - MTA Angelus; G2 - CP/ZrO2; G3 - MTA/NPsAg; G4 -CP/ZrO2/NPsAg. O pH foi analisado em pHmetro digital, a solubilidade pela perda de massa e o tempo de presa pelo teste de Gilmore. A resistência à compressão foi avaliada em ensaio mecânico. Para análise da radiopacidade, as amostras foram radiografadas com uma escala de alumínio. Os resultados foram submetidos aos testes ANOVA e Tukey (p<0,05). O G3 apresentou aumento de pH e diminuição da solubilidade e tempo do presa inicial e final. O G4 apresentou diminuição da solubilidade e aumento da resistência à compressão. A radiopacidade dos materiais foi superior a 4 mmAl. As associações G3 e G4 apresentam propriedades físico-químicas e mecânicas adequadas. Capítulo 2: Bactérias na forma planctônica foram colocadas sobre o cimento fresco e a análise foi realizada em espectrofotômetro. Na avaliação antibiofilme, os materiais foram colocados em contato com biofilme de E. faecalis formado sobre blocos de dentina e analisados pela contagem de unidades formadoras de colônia. Os resultados foram submetidos aos testes ANOVA e Tukey (p<0,05). Na forma planctônica, melhores resultados foram encontrados no G2 e G4. Maior redução de biofilme foi apresentada pelos G3 e G4. A incorporação de NPsAg ao CP e MTA, melhora a atividade antibacteriana e antibiofilme dos materiais à base de silicato de cálcio.

The bismuth oxide replacement by zirconium oxide (ZrO2) and the addition of silver nanoparticles may improve the physicochemical, mechanic and antimicrobial properties. Chapter I: It was evaluated pH, solubility, setting time, radiopacity and compressive strength. Groups: G1-MTA Angelus; G2-PC/ZrO2; G3-MTA/NPsAg, G4-PC/ZrO2/NPsAg. The pH was measured with a digital pH meter, the solubility by the weight loss and the setting time was evaluated by Gilmore needle. Compressive strength was tested in universal testing machine. For radiopacity analysis material samples were radiographed alongside an aluminium step-wedge. The results were submitted to ANOVA and Tukey tests (p<0.05). The G3 showed a pH increase and a decrease of solubility and initial and final setting time. The G4 showed a decrease in solubility and an increase of compressive strength. All materials presented radiopacity greater than 4 mmAl. The G3 and G4 associations showed good physicochemical and mechanical properties. Chapter 2: For the first test bacterias in planktonic form were placed over fresh cement, and the analysis was performed in spectrophotometer. Also for the antibiofilm test, the samples were placed in direct contact with E. faecalis biofilm previously induced on bovine dentine and analysed by the counting of colony-forming units. The results were submitted to ANOVA and Tukey tests (p<0.05). On the planktonic form, the best results were showed by G2 and G4. The greater reduction of biofilm were showed by G3 and G4. The incorporation of NPsAg to PC and MTA improves the antibacterial and antbiofilm activity of calcium silicate cements

QSAR method and its application to toxicity prediction of metal nanomaterials / 中国药理学与毒理学杂志

Quantitative structure activity relationship ( QSAR ) study attempts to correlate chemical structure with activity using statistical approaches and is now being applied to high throughput toxicity screening and prediction of nanomaterials. This paper is interded to discuss the present QSAR study methods of nanomaterials based on traditional QSAR study, such as the use of measurement instrument and quantum chemistry methods of structure descriptor selection, evaluation criteria for the quality of published experimental data on nanomaterials, modeling methods such as K-nearest neighbor ( KNN) and support vector machine(SVM), validation methods such as leave-one-out(LOO) and leave-N-out ( LNO) . We also review the problems and challenges existing in this area and predict future development.

Release properties of titanium-based nano-silver coating / 中国组织工程研究

BACKGROUND:Surface modification of orthopedic implants can reduce or prevent bacterial adhersion. Bacteriostatic and bactericidal ingredients released from special coating of metal surfaces prevent orthopedic surgery infection. OBJECTIVE:To prepare hydroxyapatite/nano-silver composite coating on the surface of medical titanium based on different preparation parameters and to observe the release properties of silver ions on the composite material surface in the simulated body fluid. METHODS:Using pulse electrochemical methods, hydroxyapatite and nano-silver were deposited in the solution containing silver, calcium and phosphate ions. Scanning electron microscopy, X-ray diffraction and energy dispersive spectroscopy were used to characterize its morphology and composition. The composite titanium materials containing 0.5, 1 mmol/L silver were immersed in the simulated body fluid, and Ag+concentration was detected by atomic absorption spectrometry at the different time points. RESULTS AND CONCLUSION:Nanoparticles were uniformly distributed in the coating which was interwoven with the nano needle-like hydroxypatite and dot-like silver particles. After high temperature processing, the coating became denser, and hydroxypatite became more crystal and silver particles exhibited no agglomeration. In the simulated body fluid, Ag+release was maximal at 1-7 days and became stable at 7-30 days which maintained an effective antimicrobial concentration. The material containing 0.5 mmol/L Ag+showed a lower amount of Ag+released than cytotoxic concentration at 30 days, but the material containing 1 mmol/L Ag+could release the total of Ag+close to the critical value of celltoxicity at 30 days. Above al , the material containing 0.5 mmol/L Ag+is more secure in the clinical application.

Preparation of amphiphilic superparamagnetic composite particles with tumor targeted MRI contrast agent / 中国组织工程研究

BACKGROUND:Superparamagnetic iron oxide nanoparticles (Fe3O4 NPs) have been widely used in MRI. It is vital to prepare the superparamagnetic MRI contrast agent with high stability, biocompatibility and tumor targeting in order to prevent the aggregation of Fe 3 O 4 NPs and realize the high-precision diagnose of tumor. OBJECTIVE:To prepare the amphiphilic superparamagnetic composite particles with tumor targeting mediated by folate receptor. METHODS:The stable amphiphilic superparamagnetic composite particles with tumor targeting function were prepared by coating the Fe3O4 NPs with a Pluronic F127-folic acid conjugate, which was synthesized via an esterification reaction between the carboxyl group of the tumor targeting molecule, folic acid and the hydroxyl group of an amphiphilic triblock copolymer, Pluronic F127. The resultant Pluronic F127-folic acid-Fe3O4 composite particles were characterized by transmission electron microscopy, Fourier transform infrared-spectra, UV-vis absorption spectra, thermal gravimetric analysis, vibrating sample magnetometer and T2-weighted imaging. WST assay was used to characterize their cytotoxicity preliminarily. RESULTS AND CONCLUSION:The Pluronic F127-folic acid conjugates were prepared via esterification reaction. Then Fe 3 O 4 NPs were wrapped with Pluronic F127-folic acid to result in the superparamagnetic composite particles with wel dispersion and biocompatibility. The size of most superparamagnetic composite particles was less than 200 nm and the size of Fe 3 O 4 core was 10-20 nm from the observation of transmission electron microscopy. The results from the Fourier transform infrared-spectra and UV-vis absorption spectroscop confirmed that folic acid molecules were modified on the surface of the superparamagnetic composite particles successful y. The mass ratio of Pluronic F127-folic acid conjugate was determined by thermal gravimetric analysis as 27.2 wt%in the resultant Pluronic F127-folic acid-Fe 3 O 4 composite particles. The saturated magnetic intensity of the superparamagnetic composite particles was 47.35 emu/g by vibrating sample magnetometer and the relaxation rate was 0.025×106 mol/s from MRI. The WST assay showed the negligible cellcytotoxicity of Pluronic F127-folic acid-Fe3O4. The superparamagnetic composite particles have potential application as the MRI contrast agents with tumor targeting, and the Pluronic F127-folic acid-Fe 3 O 4 composite particles is expected to be used as a MRI contrast agent for tumor targeting.

Preparation of nanorods probes targeting cancer cells and uptake of HepG2 cells in vitro / 中华放射学杂志

Objective To develop a cancer cell targeting probe based on silica-coated gold nanorods and investigate its optics properties and its targeting effect on human hepatocellular carcinoma HepG2 cells in vitro.Methods Preparation of gold nanorods (GNRs) by seeded growth method,and then the spherical core-shell silica-coated gold nanorods were successfully prepared by a sol-gel method,finally the GNRs@SiO2 was conjugated with folate (GNRs@SiO2-FA).The characteristics of GNRs@SiO2-FA were studied using transmission electron microscopy,and UV spectra.The cells were divided into 2 groups randomly,adding GNRs@SiO2-FA and GNRs solution respectively at the gold concentration of 40.0 × 10-6,20.0 ×10-6,10.0 × 10-6,5.0 × 10-6,2.5 × 10-6,and the MTT method was applied to detect the absorbance (A value) and study the cytotoxicity of GNRs@SiO2-FA and GNRs.The cells were divided into 2 groups randomly,and incubated with the same concentration of GNRs@SiO2-FA and GNRs@SiO2 solution respectively,at 2,4,8,16,24 h,and the targeting of GNRs@SiO2-FA cellular uptake were detected by ICPMS by observing the process of GNRs@SiO2-FA into the cells by transmission electron microscopy (TEM).The data represented by (-x) ± s ; single factor analysis of variance were compared between the 2 groups ; and the differences were significant when P ＜ 0.05.Results UV spectrum confirmed the successful preparation of GNRs@SiO2-FA.The A value of the same concentration group was variance analysised,and the differences between the 2 groups was statistically significant (all P ＜ 0.01) with the gold element concentration from high to low:F =191.876,265.419,77.987,52.061,18.745.The ICP-MS confirmed GNRs@SiO2-FA could specifically bind with HepG2 cells.GNRs@SiO2 group gold element content at 2,4,8,16,24 h was (256.7±3.3),(602.8±2.4),(1067.1±3.6),(1998.5±4.3),(2078.5±1.3) mg/kg and GNRs@SiO2-FA group was(693.1 ±2.0),(1432.0 ±2.6),(2331.3 ±3.5),(2484.5 ±5.0),(2589.7 ±2.1)mg/kg,and the 2 groups was statistically significant (F =3278.070,34287.199,85434.870,18333.454,42412.973,P ＜0.01).TEM results showed that a small amount of nano probes were in the cytoplasm after cultured with GNRs@SiO2-FA cells 1 h,and that,a lot of probe were in the cytoplasm,4-24 h later,but there was no probe in the nucleus.Conclusion The prepared Folate-conjugated gold nanorods has good performance on biocompatibility and targeting.

A novel approach for the microbial production and optimization of gold nanoparticles- an alternate approach to chemical synthesis.

Nanotechnology is the application of science to control matter at the molecular level. A nanometer (nm) is one billionth of a meter, or roughly the length of three atoms side by side. A nanoparticle is a microscopic particle with atleast one dimension less than 100 nm. The applilcation of nanoscale materials and structures, usually ranging from 1 to 100 nanometer are an emerging area of nanoscience and nanotechnology. Gold nanoparticles, in particular, are of interest, due to their stability under atmospheric conditions, resistance to oxidation and biocompatibility. Microorganisms as possible eco–friendly nanofactories can exert control over size, morphology, composition and crystallographic orientation of the as–prepared metal nanostructured particles. In the area of nanotechnology, the development of techniques for the controlled synthesis of metal nanoparticles of well defined size, shape and composition is a big challenge. This work was highly focused on the Gold nanoparticles production from Pseudomonas sp. and concentrating the work towards the production at controlled size by means of various parameter optimization studies like pH, temperature and concentration. The optimization work was characterized by means of TEM. With the results of TEM, the small sized nanoparticle of about 10nm was observed at pH of 9 and 12nm was produced at the pH of 3. Low temperature of 25oC favored the small size nanoparticle at a concentration of 250 mg/l using HAuCl4.