فهرست مطالب mahdi adabi

Given the global problem of antibiotic resistance among pathogens, researchers are looking for appropriate treatment alternatives to eliminate infections. Application of probiotics and their products can be a practical solution. This study aimed to investigate the inhibitory effect of cell-free supernatant (CFS) of probiotics against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus).

The effect of CFS of eight strains of probiotics against E. coli and S. aureus was evaluated by well diffusion method. The agent with the highest inhibition diameter was selected to investigate other antibacterial properties. They included minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and timed kill effect. Surface electron micrographs were taken to compare the treated versus untreated bacteria with CFS of Lactobacillus acidophilus (SLA) LAFTI-L10 DSL. Finally, the percent viability of the Hu02 cells was investigated after 24, 48 or 72 hours of incubation with SLA at various concentrations.

Among the tested strains, SLA showed the highest inhibitory diameter against E. coli and S. aureus (P≤0.005). Also, the MIC of SLA was equal to those of E. coli and S. aureus (12.5 μL/mL) but was different in their MBC. Almost 100% of bacteria removed after exposure to SLA (20 min.). The results of log CFU/mL demonstrated that SLA had bactericidal effect against S. aureus and E. coli. The toxicity assays showed that the percent viability of the Hu02 cells was 31.71 to 81.09 after 24, 48 or 72 hours exposure.

Our results suggest that SLA can be a suitable, effective and safe alternative to antibiotics.

 The emergence of multidrug resistance among nosocomial pathogens has prompted researchers to look for new antibacterial sources. Metal nanoparticles and probiotic products have attracted the attention of researchers. However, combination therapy is an attractive alternative in this field.

 This study evaluated the antibacterial activity and toxicity of Zinc Oxide nanoparticles (ZnO-NPs) combined with Cell-free Supernatant (CFS) of Lactobacillus plantarum (L. plantarum) and Lactobacillus acidophilus (L. acidophilus) alone and in a novel mixture.

 Antibacterial effects and cytotoxic properties of ZnO-NPs, CFS of L. plantarum (SLP), and CFS of L. acidophilus (SLA) were determined alone and in a mixture against ESKAPE strains. In addition, the viability percentage of the cells was evaluated after exposure to these agents.

 Antibacterial mixtures (ZnO-NPs with SLP or ZnO-NPs with SLA) demonstrated synergistic and additive effects against Pseudomonas aeruginosa (FIC≤0.75), Acinetobacter baumannii (FIC = 1), and Escherichia coli (FIC≤0.75). The viability percentage of the cells after 24 h of exposure to a mixture of ZnO-NPs and SLA (about 50%) was more than when the cells were exposed to ZnO-NPs alone (about 30%) at the same concentration.

 A mixture of ZnO-NPs and CFS of probiotics can be an alternative to antibiotics, with more effectiveness and fewer side effects.

Extracellular vesicles (EVs) are small particles ranging from 30 - 1000 nm released by different cells to mediate cell-cell communication. The content of these particles mirrors the cellular properties of their producing cells. The extracellular vesicles, including exosomes and microvesicles, could exert the same therapeutic effects as stem cell therapy. However, these stem cell-derived particles (cell-free derivatives) do not have concerns associated with stem cell-based therapies. Among various mesenchymal stem/stromal cells, Menstrual Blood Stem Cells (MenSCs) are known for their high proliferative activity, ease of harvesting, lack of moral dilemma, and high differentiation potential. Extracellular vesicles derived from MenSCs have widely been employed in various preclinical studies for regenerative purposes. This paper aims to provide an overview of the therapeutic utility of MenSCs-derived EVs in regenerative medicine. We also reviewed the current knowledge on the cellular profile, biogenesis, separation, and action mechanism of MenSCs-derived EVs in organ regeneration.

In this study, we prepared methotrexate (MTX) loaded chitosan/polyvinyl alcohol (PVA) nanofibers using electrospinning method. The prepared nanofiber mats were soaked into the glutaraldehyde solution for crosslinking. The ratio of chitosan/PVA was 1:9 and 1:7, and the crosslinking time was 24 hrs and 36 hrs. In vitro release study was performed on four formulations of nanofibers. Determination of contact angle, SEM, and MTT assay on U-87 MG cell line and MCF-7 cell line were carried out by those formulations of nanofibers. SEM images showed that the average fiber diameter was 221 nm with a range of 94–410 nm and also water contact angle was 24.3o. In vitro release profile of nanofibers with the ratio of chitosan/PVA of 1:9 and crosslinking time of 36 hrs was more acceptable compared to other ones. After 24 hrs, Chitosan/PVA nanofibers mat containing MTX had 18% and 20% cytotoxicity on U87MG and MCF7 cell lines, respectively. In conclusion, MTX loaded chitosan/PVA nanofibers would be an appropriate therapeutics implant for cancer therapy; however, more studies are also needed.

In this research, the fabrication of aptasensor prepared by immobilization of Penicillin aptamer on gold nanoparticles (AuNPs) electrodeposited onto electrospun carbon nanofiber (ECNF) mat was reported to detect Penicillin antibiotic in the milk. The AuNPs/ECNF mat electrode was firstly produced using the electrospinning, heat treatment and electrodeposition process, respectively. Then, the Penicillin aptamer (pDNA) was immobilized on the AuNPs/ECNF mat electrode. The effects of layer thickness of AuNPs, amount of immobilized pDNA, incubation period of pDNA and Penicillin, temperature and pH of experiment solution on the electrochemical response were studied by cyclic voltammetry (CV) technique. The results revealed that the suitable thickness of AuNPs was achieved at 3mM HAuCl4concentration. An enhancement in the electrochemical current response was also observed with increasing pDNA in the electrolyte. Moreover, the increment of incubation time led to improvement of CV peak currents. Meanwhile, the maximum peak currents of CV were obtained in the solution with pH of 7 at 35 °C.

Methotrexate MTX as a chemotherapeutic agent has the potential to be used in the treatment of brain tumors, but it is less used due to insufficient penetration into the brain parenchyma. By designing nanotechnology-based systems, it can be possible to overcome these limitations. In this study, the sonication method was used to prepare MTX loaded human serum albumin HSA nanoparticles. The results indicated that MTX loaded HSA nanoparticles have the size less than 100 nm. The obtained values for drug loading and encapsulation efficacy were 3 and 47, respectively; and the results of thermal analysis of nanoparticles demonstated the amorphous form of MTX in HSA. In the release profile, slow and controlled release of nanoparticles was also observed in the neutral environment. In addition, the results indicated the decreased cytotoxic effects of MTX loaded HSA nanoparticles in comparison with free MTX. Therefore, the proposed formulation can have high potential in drug delivery systems to glioblastoma cells.

The size of polymeric nanoparticles is considered as an effective factor in cancer therapy due to enterance into tumor tissue via the EPR effect. The purpose of this work was to investigate the effective parameters on poly(lactic-co-glycolic acid)-paclitaxel (PLGA –PTX) nanoparticles size.
We prepared PLGA-PTX nanoparticles via single emulsion and precipitation methods with variable paremeters including drug concentration, aqueous to organic phase volume ratio, polymer concentration, sonication time and PVA concentration.
PLGA-PTX nanoparticles were characterized by dynamic light scattering (DLS) and scanning electron microscopy (SEM). The results exhibited that the diameter of nanoparticles enhanced with increasing drug, polymer and PVA concentrations whereas organic to aqueous phase volume ratio and sonication time required to the optimization for a given size.
The precipitation method provides smaller nanoparticles compared to emulsion one. Variable parameters including drug concentration, aqueous to organic phase volume ratio, polymer concentration, sonication time and PVA concentration affect diameter of nanoparticles.

 Nanoparticles offer an attractive platform for drug delivery through a wide variety of the body's physiological barriers. Furthermore, modification of nanoparticle surface with moeites such as Poloxamer188 can enhance their accumulation and localization at disease site. In this work, we investigated the physiochemical effect of a scavenger receptor (SR-BI) interacting moiety coated on the surface of methotrexate (MTX)-loaded PLGA nanoparticles.
 Methotrexate-loaded PLGA nanoparticles were prepared by a single step nanoprecipitation technique. The prepared nanoparticles were characterized by dynamic light scattering (DLS) and scanning electron microscopy (SEM) for their size and morphology respectively. In vitro drug encapsulation efficiency (EE) and relative drug loading (DL) of nanoparticles were examined by UV-Vis spectrophotometry.
 The results showed that the mean diameter of nanoparticles and zeta potential increased when more poloxamer188 was added to preparation process.The DL and EE of MTX increased with increase in poloxamer188/PVA ratio. In vitro release of MTX from PLGA nanoparticle was extended by increasing poloxamer188 in preparation process.
 MTX loaded PLGA nanoparticle modified with PVA and poloxamer 188 with suitable sizes and physiochemical properties can potentially improve drug delivery.

This paper investigates the validity of Artificial Neural Networks (ANN) model in the prediction of electrospun kefiran nanofibers diameter using 4 effective parameters involved in electrospinning process. Polymer concentration, applied voltage, flow rate and nozzle to collector distance were used as variable parameters to design various sets of electrospinning experiments for production of electrospun kefiran nanofibers. The Scanning Electron Microscopy (SEM) was used to investigate the morphology and evaluate the size of the nanofiber. Data set was drawn using k fold cross-validation method, which was the most suitable scheme for the volume of the data in this work. Data were partitioned into the five series and trained and tested via ANN method. The Scanning Electron Microscopy (SEM) images of the generated nanofiber samples were confirmed that all of the samples were fine and defect-free. Our results indicated that the network including four input variables, three hidden layers with 10, 18 and 9 nodes in each layer, respectively, and one output layer obtained the highest efficiency in the testing set. The mean squared error (MSE) and linear regression (R) between observed and predicted nanofibers diameter were 0.0452 and 0.950, respectively. The results demonstrated that the proposed neural network was appropriately performed in assessing the input parameters and prediction of nanofibers diameter.