Centaurea behen leaf extract mediated green synthesized silver nanoparticles as antibacterial and removing agent of environmental pollutants with blood compatible and hemostatic effects.

The present study focused on evaluating the antibacterial properties, radical scavenging, and photocatalytic activities of Centaurea behen-mediated silver nanoparticles (Cb-AgNPs). The formation of Cb-AgNPs was approved by UV-Vis spectrometry, Fourier-transform infrared spectroscopy, transmission electron microscopy, scanning electron microscopy (SEM), energy dispersive X-ray and X-ray diffraction. The results showed that the obtained AgNPs have a maximum absorbance peak at 450 nm with spherical morphology and an average size of 13.03 ± 5.8 nm. The catalytic activity of the Cb-AgNPs was investigated using Safranin O (SO) solution as a cationic dye model. The Cb-AgNPs performed well in the removal of SO. The coupled physical adsorption/photocatalysis reaction calculated about 68% and 98% degradation of SO dye under solar irradiation. The Cb-AgNPs inhibited the growth of gram-negative or positive bacteria strains and had excellent DPPH radicals scavenging ability (100% in a concentration of 200 µg/ml) as well as a good effect on reducing coagulation time (at concentrations of 200 and 500 µg/mL reduced clotting time up to 3 min). Considering the fact that green synthesized Cb-AgNPs have antioxidant and antibacterial properties and have a good ability to reduce coagulation time, they can be used in wound dressings. As well as these NPs with good photocatalytic activity can be a suitable option for degrading organic pollutants.

Synthesis, in silico, in vitro and in vivo studies of novel natural-based arylidenes curcumin as potential glycohydrolase digestive enzymes inhibitors.

Diabetes is one of the most common metabolic diseases in humans and the use of herbal medicines is of great clinical importance to inhibit carbohydrate-hydrolyzing enzymes and reduce blood glucose levels in diabetic patients. Inhibition of glycosidase activity is an effective way to treat and prevent diabetes. Therefore, in this study, curcumin-based benzaldehyde derivatives were synthesized and used as influential agents in the treatment of diabetes with inhibitory properties against two carbohydrate-hydrolyzing enzymes α-glucosidase (α-Glu) and α-amylase (α-Amy) as significant therapeutic targets for reducing postprandial hyperglycemia. Overall, the findings showed that due to the specific inhibitory activity against α-Glu in comparison with α-Amy, as well as more stability and antioxidant activity than curcumin, C5 and C8 derivatives are potentially important anti-diabetic drugs, not only to decrease glycemic index but also to limit the activity of the main production pathways of reactive oxygen species (ROS) in diabetic patients.Communicated by Ramaswamy H. Sarma.

Interactions of insulin with tragacanthic acid biopolymer: Experimental and computational study.

Alternative methods for insulin delivery instead of subcutaneous injection in diabetic patients is of great essential, and biocompatible polymers are one of the most efficient vehicles for this purpose. This research aims to investigate the capability of tragacanthic acid (TA) to bind insulin and release it under physiological conditions without alteration in the structure and conformation of insulin. Interactions between TA and insulin were studied using spectroscopic techniques and computational modeling by docking and molecular dynamics simulations. Our results demonstrate an entropy-driven spontaneous interaction between insulin and TA, where hydrogen bonds act as the main enthalpic contribution. According to our findings, the weak interaction between insulin and TA provides the basis for efficient capture and appropriate release of insulin by TA as a potential part of the insulin delivery system. In conclusion, tragacanth acid can be a proper candidate for insulin delivery.

Preparation and Characterization of Silk Fibroin Nanoparticles as a Potential Drug Delivery System for 5-Fluorouracil.

Purpose: The aim of this study is to prepare 5-fluorouracil (5-FU) loaded silk fibroin nanoparticles (SFNPs) and to achieve a controlled release delivery system with the high loading capacity. Methods: SFNPs with 1:1, 1:3, and 1:10 ratios of 5-FU to silk fibroin were prepared. SFNPs were characterized by Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) analysis, Scanning electron microscope (SEM), and Transmission electron microscope (TEM). Loading efficiency, in vitro release, and cell viability were studied for optimal SFNPs. Results: The ratio of 1:1 was optimal formulation with the size and polydispersity index (PDI) of 221.03 nm and 0.093 before freeze drying, and 286.7 nm and 0.154 after freeze drying by lactose, respectively. The loading efficiency and loading content of this ratio were 52.32% and 34.35%, respectively. FT-IR and XRD analysis indicated the conformational change (from random coil to ß-sheet) in the structure of nanoparticles by increasing amount of the drug, which caused the smaller size, the higher loading efficiency, and the slower release pattern. The drugloaded nanoparticles reached to the half maximal inhibitory concentration (IC50) that were comparable with free drug on MCF7 (human breast cancer) cell line. Conclusion: This study was planned to achieve a promising controlled release drug delivery system for carrying 5-FU, as a potent anticancer drug. SFNPs were found proper candidates for delivery of a hydrophilic drug such as 5-FU.

Microfluidic-assisted preparation of PLGA nanoparticles for drug delivery purposes: experimental study and computational fluid dynamic simulation.

This study, for the first time, tries to provide a simultaneous experimental and computational fluid dynamic (CFD) simulation investigation for production of uniform, reproducible, and stable polylactic-co-glycolic acid (PLGA) nanoparticles. CFD simulation was carried out to observe fluid flow behavior and micromixing in microfluidic system and improve our understanding about the governing fluid profile. The major objective of such effort was to provide a carrier for controlled and sustained release profile of different drugs. Different experimental parameters were optimized to obtain PLGA nanoparticles with proper size and minimized polydispersity index. The particle size, polydispersity, morphology, and stability of nanoparticles were compared. Microfluidic system provided a platform to control over the characteristics of nanoparticles. Using microfluidic system, the obtained particles were more uniform and harmonious in size, more stable, monodisperse and spherical, while particles produced by batch method were non-spherical and polydisperse. The best size and polydispersity index in the microfluidic method was obtained using 2% PLGA and 0.0625% (w/v) polyvinyl alcohol (PVA) solutions, and the flow rate ratio of 10:0.6 for PVA and PLGA solutions. CFD simulation demonstrated the high mixing intensity of about 0.99 at optimum condition in the microfluidic system, which is the possible reason for advantageous performance of this system. Altogether, the results of microfluidic-assisted method were found to be more reproducible, predictable, and controllable than batch method for producing a nanoformulation for delivery of drugs.

Inhibitory effects of selected antibiotics on the activities of α-amylase and α-glucosidase: In-vitro, in-vivo and theoretical studies.

Antibiotics are effective drugs that are used to treat infectious diseases either by killing bacteria or slowing down their growth. The well-adapted structural features of antibiotics for the inhibition/activation of enzymes include several available hydrogen bond (H-bond) acceptors and donors, flexible backbone and hydrophobic nature. The substrates of α-amylase and α-glucosidase, known as key absorbing enzymes, have functional groups (OH groups) rembling antibiotics. Given the possibility of developing in diabetics and the significant association between diabetes and infection, the present study was conducted to investigate the influences of tetracycline (TET), kanamycin (KANA), lincomycin (LIN), erythromycin (ERM) and azithromycin (AZM) on α-glucosidase and α-amylase activities with calculating IC50 and Ki values. Also, the efficacy of antibiotics after oral administration was evaluated by analysis of blood glucose concentrations in rats, as well as a molecular docking analysis was explored. α-glucosidase and α-amylase activities were inhibited in a dose dependent fashion by TET with an IC50 of 38.7 ±â€¯1.4 and 47.8 ±â€¯3.2 µM respectively, by KANA with an IC50 of 46.2 ±â€¯1.6 and 65.1 ±â€¯1.6, by LIN with an IC50 of 59.1 ±â€¯2.1 and 51.3 ±â€¯4.1, by ERM with an IC50 of 94.9 ±â€¯4.7 and 65.7 ±â€¯3.8 and by AZM with an IC50 of 69.4 ±â€¯4.4 and 103.6 ±â€¯6.2. Moreover, the Ki values of TET were calculated as 4.4 ±â€¯0.6 and 8.4 ±â€¯0.8 µM for α-glucosidase and α-amylase in a competitive-mode and mixed-mode inhibition. In addition, to communicate with the active site of α-glucosidase and α-amylase respectively, TET presented a binding energy of -9.8 and -8.8 kcal/mol, KANA -7.9 and -7.1, LIN -7.8 and -6.7, ERM -6.8 and -6.4, and AZM -6.4 and -7.5 kcal/mol. In-vivo studies also suggested a decrease in the blood glucose concentration after administering TET compared to the positive controls (P < 0.01). The results obtained from the present research can therefore help the scientific community explore the possible interconnection between the clinical side-effects of antibiotics and their α-glucosidase and α-amylase inhibitory properties, as the target enzymes in hypoglycemia conditions.

Combined Unfolded Principal Component Analysis and Artificial Neural Network for Determination of Ibuprofen in Human Serum by Three-Dimensional Excitation-Emission Matrix Fluorescence Spectroscopy.

This study describes a simple and rapid approach of monitoring ibuprofen (IBP). Unfolded principal component analysis-artificial neural network (UPCA-ANN) and excitation-emission spectra resulted from spectrofluorimetry method were combined to develop new model in the determination of IBF in human serum samples. Fluorescence landscapes with excitation wavelengths from 235 to 265 nm and emission wavelengths in the range 300-500 nm were obtained. The figures of merit for the developed model were evaluated. High performance liquid chromatography (HPLC) technique was also used as a standard method. Accuracy of the method was investigated by analysis of the serum samples spiked with various concentration of IBF and an average relative error of prediction of 0.18% was obtained. The results indicated that the proposed method is an interesting alternative to the traditional techniques normally used for determination of IBF such as HPLC.

De-Esterified Tragacanth Microspheres Loaded into Eudragit S-100 Coated Capsules for Colon-Targeted Delivery.

The objective of this study was to develop a novel bacterially-triggered micro-particular system of de-esterified tragacanth (DET) in combination with Eudragit S-100 coated capsules for colon drug delivery of 5-fluorouracil (5-FU) using microemulsion method. The loading study was conducted at different drug-to-polymer ratios and cross-linker concentrations. The maximum loading efficiency was achieved, 44.1% at 1:5 drug-to-polymer ratio and 0.7% cross-linker concentration. The FTIR results also confirmed the encapsulation of 5-FU in microspheres. The release profile was dependent on the cross-linker concentration, environmental pH, and presence of pectinase enzyme. Microspheres inserted into Eudragit S-100 coated capsules released less than 5% of the drug at stomach and small intestine pH levels, whereas 70% of the drug was released at colon pH levels, and about 25% of the drug did not release unless in the presence of pectinase enzyme. To omit burst release, microspheres were washed with water, and the release became pH independent, and was just achieved in the presence of pectinase enzyme. 5-FU loaded microspheres with an IC50 value of 80 µg/mL were as effective as the free drug on HT-29. Generally, the results demonstrated that drug-loaded microspheres inserted into Eudragit S-100 coated capsules can be effective for colon-targeted delivery.

De-esterified tragacanth-chitosan nano-hydrogel for methotrexate delivery; optimization of the formulation by Taguchi design.

The objective of the present study was to prepare and characterized de-esterified tragacanth-chitosan nanoparticles (DET-CS NPs) as a novel carrier for methotrexate, with a view to improve drug efficacy and target ability. The preparation process was optimized using Taguchi design. NPs were characterized for size, zeta potential, morphology, thermal stability, loading efficiency, cytotoxicity and cellular uptake. Taguchi design indicated that the molecular weight of chitosan possessed the most effect on the zeta potential, PDI, and zeta deviation, and the size of nanoparticles was significantly affected by the DET concentration. The size and zeta potential of drug loaded nanoparticles at optimum condition were 322.9 ± 26 nm and 17.3 ± 5.73 mV, and thermal analysis indicated ionic bond between DET and CS in NPs. The loading efficiency was 20.32% ± 2.01, and the sustained release was observed within nine days. The IC50 was 280 µg/mL in HT-29, and the mitochondrial membrane potential in HT-29 was reduced more than that in MCF-7. The uptake of NPs in HT-29 was higher than that in MCF-7, and active endocytosis was the key mechanism of uptake. These phenomena altogether make DET-CS NPs a proper choice for targeted drug delivery to cells containing asialoglycoprotein receptors.

Direct evidences for the groove binding of the Clomifene to double stranded DNA.

It has been reported that the antiestrogen Tamoxifen induces liver tumors in rats and genotoxic effects in vitro through DNA interaction. So, it can be proposed that its structural analogue, Clomifene, also can bind to DNA. To test this hypothesis, the DNA binding properties of Clomifene have been studied by absorption spectroscopy, fluorescence spectroscopy, cellular uptake, cell viability, cell proliferation and molecular modeling techniques. Evidences are provided that Clomifene could interact with DNA via minor groove interaction mode. The negative ΔG value implied that the interaction occurred between DNA and Clomifene spontaneously. Also, the positive ΔH and positive ΔS values indicated that the binding of Clomifene with DNA is mainly entropy driven and the enthalpy is unfavorable parameter. This also suggests that the hydrophobic interaction plays a major role in the binding with overall binding constant of K=5.645×107M-1 at 298K. From the results of docking, it can be concluded that Hydrogen bonds is also one of the most important interactions. The increase in entropy of system after binding might be due to the destruction of the DNA structure.

Preparation and characterization of silk fibroin hydrogel as injectable implants for sustained release of Risperidone.

The principal objective of the present study is to achieve a depot formulation of Risperidone by gelation of silk fibroin (SF). For this purpose, hydrochloric acid (HCl)/acetone-based and methanol-based hydrogels were prepared with different drug/polymer ratios (1:3, 1:6, and 1:15). For all the drug-loaded methanol-based hydrogels, gel transition of SF solutions occurred immediately and the gelation time was 1 min, while the gelation time of HCL/acetone-based hydrogels was around 360 min. According to the results obtined from Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) spectra, solvent systems and Risperidone could induce ß-sheet structure, but HCL/acetone system had the lowest effect on induction of ß-sheets. The crystallinity was increased by increasing the amount of Risperidone, and drug to polymer ratio of 1:3 possessed the highest crystallinity. Thermogravimetric analysis (TGA) indicated that increasing the amount of drug in formulation increased the stability of hydrogels, and methanol-based hydrogel with a ratio of 1:3 had the most stable structure. The release rate of Risperidone from methanol-based hydrogel at ratio of 1:3 was lower than that for HCl/acetone-based one, and it decreased by increasing the amount of Risperidone. The release of Risperidone from methanol hydrogel at ratios 1:3 and 1:6 continued up to 25 d which is acceptable for depot form of Risperidone and shows that the extended release of Risperidone was achieved successfully. In conclusion, SF hydrogel with the ability to respond to the environmental stimuli is an excellent candidate for injectable implants for extended release of Risperidone.

Experimental and computational studies on the binding of diazinon to human serum albumin.

In the present research, the binding properties of diazinon (DZN), as an organophosphorus herbicide, to human serum albumin (HSA) were investigated using combination of spectroscopic, electrochemistry, and molecular modeling techniques. Changes in the UV-Vis and FT-IR spectra were observed upon ligand binding along with a significant degree of tryptophan fluorescence quenching on complex formation. The obtained results from spectroscopic and electrochemistry experiments along with the computational studies suggest that DZN binds to residues located in subdomains IIA of HSA with binding constant about 1410.9 M-1 at 300 K. From the thermodynamic parameters calculated according to the van't Hoff equation, the enthalpy change ΔH° and entropy change ΔS° were found to be -16.695 and 0.116 KJ/mol K, respectively. The primary binding pattern is determined by hydrophobic interaction and hydrogen binding occurring in so-called site I of HSA. DZN could slightly alter the secondary structure of HSA. All of experimental results are supported by computational techniques such as docking and molecular dynamics simulation using a HSA crystal model.

Preparation and physicochemical characterization of camptothecin conjugated poly amino ester-methyl ether poly ethylene glycol copolymer.

In the present study, camptothecin grafted poly amino ester-methyl ether polyethylene glycol (CPT-PEA-MPEG) as a novel copolymer was synthesized by Michael reaction at different ratios of MPEG and CPT (60 : 40 and 80 : 20). The microemulsion was used to prepare nanomicelles, and in vitro cytotoxicity was performed on the HT29 cell line, and cell survival was measured by MTT assay. The syntheses were confirmed by 1H NMR and FT-IR. Several characterization methods including CMC, particle size, size distribution, and transmission electron microscopy were performed to evaluate features of prepared nanomicelles. Low critical micelle concentration, small particle size and IC50 of 0.1 mg ml-1 at MPEG to CPT ratio of 60 : 40 make this micelle a promising drug delivery carrier. CPT-PAE-MPEG nanomicelles at a MPEG : CPT ratio of 60 : 40 can be a suitable choice to improve the physiochemical properties of CPT and its therapeutic effect, while it can be potentially used as a nano-carrier for other anticancer drugs to purpose a dual drug delivery.

Insights from a combination of theoretical and experimental methods for probing the biomolecular interactions between human serum albumin and clomiphene.

In this study, the interaction of clomiphene (CLO), a non-steroidal and ovulatory stimulant drug employed in the treatment of infertility, with human serum albumin (HSA), the most abundant plasma transport protein, was investigated using spectrofluorometric, FT-IR, UV-Vis, and molecular modeling methods. The obtained results indicated that the binding of CLO to HSA led to intense fluorescence quenching of HSA via a static quenching mechanism, and that the process of CLO binding to HSA was enthalpy driven. By using experimental and theoretical methods, it was confirmed that as a result of binding CLO, slight conformational changes in HSA occurred. Also, the negative ΔH of interaction indicated that the binding of CLO with HSA was mainly enthalpy driven. The experimental and computational results suggested that hydrogen bonds and van der Waals interactions played a major role in the binding, with overall binding constants of K = 3.67 × 109 M-1 at 286 K and 6.52 × 105 mol L-1 at 310 K. Moreover, the results of molecular modeling showed that Asp234, Phe228, Leu327, and Arg209 in HSA had the highest interaction energies with the ligand.

Optimization of de-esterified tragacanth microcapsules by computational fluid dynamic and the Taguchi design with purpose of the cell encapsulation.

This work presents the development of the new De-Esterified Tragacanth (DET) microcapsules (MCs). Co-flow extrusion method was applied for producing the MCs; the processing parameters were optimized by the Taguchi design to obtain the smallest and the most spherical MCs. Computational Fluid Dynamic (CFD) modeling was accomplished to show the formation of droplets at different airflows, and finally, ßTC3 pancreatic cells were encapsulated in the MCs. The optimum MCs had 214.58µm size and 60.75% sphericality. The air pressure and the cross-linking reaction of DET were the most influential parameter in size and the sphericality of MCs, respectively. CFD showed two velocity vortices with rotational flow formed in the chamber, which caused changing the droplet moving direction. The encapsulated cells were proliferated, and cell viability was not reduced during six days. These phenomena make DET MCs a potential candidate for the cell encapsulation.

Preparation and characterization of pH-sensitive camptothecin-cis-aconityl grafted chitosan oligosaccharide nanomicelles.

Camptothecin (CPT) was introduced to water-soluble chitosan oligosaccharide (CHO) using cis-aconityl (CA), as a pH-sensitive linker, to develop a new hydrophobic structure, i.e. CPTCACHO. The triple conjugates were synthesized in three ratios (5%, 7.5%, and 10%) and characterized by Fourier transform infrared (FT-IR) and proton nuclear magnetic resonance (1HNMR). Thermo gravimetric analysis and critical micelle concentration (CMC) assessments were performed. Prepared nano-micelles were analyzed for particle size, polydispersity index (PDI), drug release and in vitro cytotoxicity. CPTCACHO 7.5% micelles as optimum micelles had a mean diameter of 50nm (observed by transmission electron microscopy), a zeta potential of +45.9mV, and a CMC of about 9.97×10-5g/L. The release results showed that CPTCACHO 7.5% has the burst release at acidic pH, and cytotoxicity study indicated that IC50 of CPTCACHO 7.5% for MCF-7 cell line was 0.8µg/mL. These properties altogether make CPTCACHO micelles, as a pH sensitive cargo with inherent cytotoxicity, a potential candidate for hydrophobic anticancer drugs.

Molecular insight into the Grandivitin- matrix metalloproteinase 9 interactions.

Grandivitin (GRA), a natural coumarin, can inhibit Matrix metalloproteinase 9 (MMP9). Binding characteristics are therefore of interest for pharmacodynamics of GRA and coumarin derivatives. A combination of spectroscopic methods and molecular modeling techniques was used to characterize interaction of GRA with MMP9. Fluorescence spectroscopy showed that GRA could quench the MMP9 fluorescence spectra. Changes in the UV-Vis and FT-IR spectra were observed upon ligand binding along with a significant degree of tryptophan fluorescence quenching on complex formation. Fluorescence studies showed that GRA has an ability to quench the intrinsic fluorescence of MMP9. Molecular modeling analysis showed that GRA to be bound in the large hydrophobic cavity of MMP9. Further investigation of the binding site of GRA within the MMP9 molecule suggested that hydrophobic contacts, hydrogen bond formation and electrostatic interactions account for the binding of GRA. According molecular dynamics (MD) simulation results the ligand can interact with the protein, with affecting the secondary structure of MMP9 and with a modification of its tertiary structure. The biological significance of this work is evident because MMP9 serves as a potential target protein for anticancer agents. The binding study of GRA with MMP9 is of great importance in pharmacy, pharmacology and biochemistry. This work can provide some key data to clinical research and supply the theoretical basis for the new drug candidate designing.

Multi-spectroscopic and molecular modeling investigation of the interactions between prantschimgin and matrix metalloproteinase 9 (MMP9).

The binding of prantschimgin (PRAN) to matrix metalloproteinase 9 (MMP9) was investigated using multiple techniques. Fluorescence spectroscopy showed that PRAN could quench the MMP9 fluorescence spectra. Changes in the UV/vis and Fourier transform infrared (FTIR) spectra were observed upon ligand binding, along with a significant degree of tryptophan fluorescence quenching on complex formation. The interaction of PRAN with MMP9 has also been studied using molecular docking and molecular dynamics (MD) simulation. The binding models demonstrated aspects of PRAN's conformation, active site interaction, important amino acids and hydrogen bonding. Computational mapping of the possible binding site of PRAN revealed that the ligand is bound in a large hydrophobic cavity of MMP9. The MD simulation results suggested that this ligand can interact with the protein, with little affecting the secondary structure. The results not only lead to a better understanding of interactions between PRAN and MMP9, but also provide useful data about the influence of PRAN on the structural conformation. The data provided in this study will be useful for designing a new agonist of MMP9 with the desired activity.

Preparation and characterization of silk fibroin/oligochitosan nanoparticles for siRNA delivery.

siRNA therapy offers hope treating diseases caused by genetic defects as well as viral infections and cancers, although it has been limited by the low stability of siRNA and its rapid degradation in the presence of nucleases as well as its low cellular uptake. In this study, oligochitosan (OC) combined with silk fibroin (SF) was formulated and proposed as a novel carrier for siRNA. The obtained SF/OC/siRNA nanoparticles (NPs) were characterized according to their physicochemical properties, such as their size, zeta potential, loading efficiency, stability, cytotoxicity, cellular uptake and transfection efficiency, and their properties were compared with those of OC polyplexes. The mean diameter of SF/OC/siRNA NPs was not significantly different compared to polyplexes, and the particle size ranged between 250 and 450 nm. Increased amounts of SF in NPs enhanced their loading efficiency, and NPs showed excellent stability in the presence of FBS and heparin compared with OC polyplexes. Additionally, MTT assays demonstrated that SF/OC/siRNA NPs had lower cytotoxicity. NPs showed better gene silencing with or without FBS, which could be attributed to increased loading efficiency, serum stability and cellular uptake. These properties suggest that SF/OC/siRNA NPs have a strong potential as gene carriers.