جستجوی مقالات مرتبط با کلیدواژه « نانوذرات » در نشریات گروه « پزشکی »

Various studies have been conducted to treat memory and learning disorders using medicinal plants and other compounds. Amygdalin, as the main compound of the seeds of Rosaceae plants, has multiple beneficial properties but can release cyanide compounds in the body. On the other hand, local drug delivery using nanoparticles has created the ability to release the drug with fewer side effects. Chitosan is one of the compounds whose nanoparticles are used in drug delivery systems. In the present study, the impact of non-capsulated and encapsulated amygdalin in chitosan nano-particles on passive avoidance memory has been studied.

In this experimental research, 150 male NMRI mice aged 5-6 weeks weighing 25-30 gr were used. All injections were done intraperitoneally. This study was conducted in three separate phases. In the first stage, different doses of ethanol were injected (0.25, 0.5, 0.75, and 1 gram per kilogram of body weight) to obtain the appropriate dose for passive avoidance memory impairment. In the second phase, after memory impairment using ethanol, the effect of different doses (6.25, 12.5, 25, and 50 mg/kg) of uncoated amygdalin on passive avoidance memory was evaluated. In the third phase, the effect of the same doses of amygdalin in the previous phase but encapsulated in chitosan nanoparticles was evaluated. The process of investigating passive avoidance memory was carried out on two consecutive days, including the training day and the test day, using the shuttle box device. Data mean and standard deviation was analyzed in GraphPad Prism software via one-way analysis of variance (ANOVA) and Tukey's test in a P< 0.05 significant level.

The results of the first phase showed that ethanol by doses of 0.75 and 1 gram per kilogram body weight at P<0.001 and by dose of 0.5 grams per kilogram body weight at P<0.01 significantly caused amnesia. The results of the second phase showed that all doses of uncoated amygdalin not only did not cause memory impairment but also significantly (P<0.0001) improved ethanol-induced amnesia. In the third phase, the results showed that although all doses of amygdalin encapsulated in chitosan nanoparticles significantly(P<0.01) cause amnesia in doses of 25 and 50 mg/kg, they can improve amnesia in a state-dependent pattern. Comprising the effect of match doses of non-capsulated and encapsulated amygdalin on the passive avoidance memory revealed no significant difference between any of the matched doses so both of them can improve the impaired memory caused by ethanol.

In this study, amygdalin received by the intraperitoneal method was able to improve the impaired avoidance memory and encapsulated in nano chitosan showed a state-dependent learning pattern, probably because cyanide was not released under the influence of the microbial flora of the digestive tract. Therefore, it seems necessary to investigate the effect of oral consumption of amygdalin on avoidance memory, spatial memory, or other cognitive activities.

Adding nanoparticles as filler aims to improve the mechanical properties of acrylic resin and reduce the incidence of fracture in them. This study aimed to investigate the effect of adding zirconium oxide and titanium oxide nanoparticles to acrylic resin on its flexural strength.

Methods and Materials:

 In this in-vitro study, surface modification of ZrO2 and TiO2 nanoparticles have been done by combining with silane coupling agent (trimethoxysilylpropyl methacrylate), and 25 samples of acrylic resin with 2.5*10*65 mm dimensions have been made. 5 groups were divided into control, 1 and 5% TiO2, 1 and 5% ZrO2. Flexural strength was evaluated by universal testing machine. Data were analyzed by One-Way ANOVA and Tukey's post hoc test. P < 0.05 was considered as statistically significant.

A significant increase in the flexural strength of acrylic resin modified with 1% zirconium oxide compared to the control sample was observed, with an average difference of 22.082 MPa (p<0.001). The difference in bending strength was significant between the control group and the groups containing nanoparticles (p<0.05). The highest and lowest bending strengths were found in the groups with 1% zirconium oxide, averaging 98.53±2.77 MPa, and 5% titanium oxide, averaging 61±1.52 MPa, respectively. There was a significant difference in flexural strength between the 1% and 5% zirconium oxide groups, with an average of 15.98 MPa (p<0.001). Additionally, there was no significant difference in flexural strength between the 1% and 5% titanium oxide groups, with an average of 4.16 MPa (p=0.06).

Based on the findings, ZrO2 nanoparticles improve and TiO2 nanoparticles weaken the flexural strength of acrylic resin. Also, by increasing the concentration of nanofiller, the mechanical properties of acrylic resin are weakened.

Because ionizing radiation and radioactive materials are not used in MRI images and their good spatial resolution, it has been widely used in the diagnosis of diseases. But for a more accurate diagnosis of some diseases, it is necessary to inject contrast material. Contrast materials are metal ions of paramagnetic elements such as gadolinium (Gd) or superparamagnetic iron oxide nanoparticles (SPIONs). This study aims to investigate the effect of echo time (TE) on the signal intensity of PVP-grafted iron oxide nanoparticles on spin echo T2-weighted images as a negative contrast material (T2-contrast).

Prepared nanoparticles (SPIONs grafted with PVP) in different concentrations (0-0.600 μmol Fe/L) that were poured inside the test tubes were spin echo T2-weighted imaged by an MRI scanner (1.5 T).

The curves of nanoparticle concentration versus the signal intensity show that with increasing nanoparticle concentration, the signal intensity decreases. Also, at a constant TE, the higher nanoparticle concentration has lower signal intensity.

The produced nanoparticle (PVP-grafted iron oxide nanoparticles) can be used in clinical work as a negative contrast material due to the behaviour it showed in different concentrations and TE.

Nanoparticles are used as a contrast agent in MRI imaging. The results of this study show that the prepared contrast agent can be used as a negative contrast agent in clinical imaging.

Nowadays, the presence of antibiotics in the environment has increasingly caused concern. Antibiotic contamination in the environment leads to the formation of antibiotic-resistant genes and antibiotic-resistant bacteria. The discharge of hospital, industrial, agricultural and local wastewater is the main route of antibiotic entry into the environment. Studies show that the conventional water treatment processes are not efficient and specifically designed to remove these polar compounds, which are mostly water-soluble, non-volatile and non-biodegradable. To destroy these pollutions, many researchers have paid attention to various technologies based on abundant sources and clean energy, such as photocatalysis, Photo-Fenton, UV-H2O2, ozonation, sonolysis and sonocatalysis. Although the contaminated water is very turbid and obscure in many areas that light can hardly penetrate into the contaminated water and limits the photocatalytic ability. Semiconductor-based sonocatalysis has many advantages in antibiotic removal applications. Because the ultrasound waves can spread well in any aqueous environment and play a sonocatalytic effect. The effectiveness of photocatalytic and sonocatalytic processes is related to factors such as irradiation time, photocatalyst dose, pH, etc. Semiconductors such as TiO2, ZnO, SnO2, and ZrO2 participate in sonocatalytic processes due to their ability to promote the valence band electron to the conduction band, leaving the hole behind, and produce free radicals for the oxidation of organic compounds. In this article, we try to provide an overview of the sonocatalytic applications of nanoparticles in the degradation of antibiotics.

Bacterial infections are a major cause of chronic infections and mortality, and antibiotics are the preferred treatment for bacterial infections. However, studies show that widespread use of antibiotics has led to the emergence of multidrug-resistant bacterial strains. Hence, the need to develop new and alternative strategies for the production of effective drugs has become an important issue. Recently, the use of nanotechnology has been widely common in various fields. Materials in the nanoscale have unique physical and chemical properties. Silver nanoparticles have different applications and their antimicrobial properties have been confirmed in several studies. This study aimed to investigate the antibacterial properties of silver nanoparticles synthesized by berberine and Hypericum perforatum extract.

In this experimental study, the antibacterial effects of synthesized nanoparticles on standard strains of Escherichia coli [ATCC 25922], Pseudomonas aeruginosa [ATCC 27853], Klebsiella pneumoniae [ATCC 9997], and Staphylococcus aureus [ATCC 29212] were investigated. The MIC content of silver nanoparticles alone and in combination with berberine and Hypericum perforatum extract was investigated for the studied bacteria using the broth microdilution method.

The results of the evaluation of the minimum inhibitory concentration [MIC] of the synthesized compounds on the studied bacteria showed that the nanoparticles synthesized by berberine and Hypericum perforatum extract had the highest antibacterial effects. However, each of the compounds Berberine and Hypericum perforatum extract alone did not show significant antibacterial properties. The results of this study also showed that the highest inhibitory concentration of nanoparticles synthesized by berberine and Hypericum perforatum extract was related to Pseudomonas aeruginosa [0.0375 mg / ml] and the lowest inhibitory concentration was related to Enterococcus faecalis [0.185 mg/ml].

The results of the present study showed that silver nanoparticles synthesized with berberine and Hypericum perforatum extract have significant antibacterial effects. As a result, nanoparticles, including silver nanoparticles, can become one of the most important alternatives to antibiotics due to their unique properties in targeting bacteria. However, achieving definitive results requires further studies in this area.

The use of plants to treat diseases has a long history. Today, due to the side effects of common drugs, turning to these natural resources is more mandatory than before. This study aimed to construct and characterize nanoliposomes containing Glycyrrhiza glabra extract and to evaluate its toxicity on healthy HFF cell lines and MCF-7 breast cancer cell lines.

Initially, licorice extract was obtained using a succulent extraction method. Subsequently, a liposomal system was prepared from SPC and cholesterol using the thin film method, and Glycyrrhiza glabra extract was loaded into the liposomes. Their physicochemical parameters were investigated using zeta-sizer and SEM devices, and the release pattern of the extract was calculated at 37ºC and 42 ºC. Finally, the toxicity of this nanosystem containing the extract on the MCF-7 breast cancer cell line and HFF skin was investigated by the MTT method.

Encapsulation, particle size, polydispersity index, and zeta potential are 64.16±3.45%, 131 nm, 0.131, and -19.1 mV, respectively. Release of the extract was slow at similar temperatures to healthy and cancer cells. Also, liposome extract was more toxic to the MCF-7 cell line than free extract, and both were less toxic to the HFF cell line.

The findings showed that the liposomal system incorporating the extract had advantageous physical and chemical characteristics. It also displayed high toxicity on the MCF-7 cell line but low toxicity on the HFF cell line. This indicates that the liposomal system may be a promising method for delivering plant compounds to specific cells.

The brain is the most complex and evolved human organ, so protecting its function is a vital issue. The blood-brain barrier formed by the microvascular system of the brain is a membrane strip that separates the blood from the extracellular compartment of the brain in the central nervous system of most vertebrates. The blood-brain barrier is a single layer of endothelial cells that consists of five parts: pericytes, astrocytes, neurons, basement membrane, and connective tissues. The blood-brain barrier is a major barrier to drug delivery to the brain. To effectively release drugs into the brain, various methods have been developed. Among them, drug delivery with nanoparticles has many advantages, including non-invasiveness, cost-effectiveness, better biodegradability, and long-term stability.

Investigating the structure and function of the blood-brain barrier, as well as the evaluation of various systems affecting this structure, especially the use of nanoparticles, can play an important role in helping to treat central nervous system diseases.

Urinary tract infections (UTIs) are one of the most common bacterial infections, particularly in women and children, which are often treated with antibiotics. Bacterial biofilms play an important role in persistent and recurrences of UTIs. A catheter-associated UTI (CA-UTI) caused by biofilm constitute a high percentage of nosocomial infections. Increasing antibiotic resistance is a serious threat to the treatment of these infections. Antibiotic resistance is an important and topical issue, which refers to the situation where antibiotics that usually kill bacteria no longer do so. Patients infected with resistant bacteria will manifest symptoms for a longer time, and the chances of the conditions getting worse will be higher. The main causes of antibiotic resistance are their incorrect use: either empirical treatment is performed (without performing antibiotic susceptibility testing); strong antibiotics are prescribed for infections that could be treated with simple antibiotics; or administration is in too small amounts, for too short a period, or at too long intervals. Therefore, alternative strategies for the prevention and treatment of UTIs caused by bacterial biofilm are needed. In the present study, a review of these new therapeutic approaches is provided including medicinal plants, probiotics, antimicrobial peptides, nanoparticles, and phages.

Silver nanoparticles are produced in large quantities in the industry and have estrogenic activities and toxic effects on different organs. This study was conducted to determine the effect of silver nanoparticles on the ovarian tissue of NMRI rats treated with alpha lipoic acid.

In this experimental study, 24 female NMRI rats were randomly divided into 4 groups of 6. The groups included the control group, oral silver nanoparticles (500 mg/kg of body weight), injected alpha lipoic acid (100 mg/kg of body weight), and silver nanoparticles (500 mg/kg of body weight) plus alpha lipoic acid (100 mg/kg body weight). The treatment was performed for 28 days. After the treatment period, blood sampling was performed from the rats’ hearts to analyze biochemical parameters (malondialdehyde, estrogen, progesterone, and total antioxidant capacity using the ferric reducing ability of plasma (FRAP) method). By dissecting the rats, the left ovaries were removed, fixed, molded, and cut, tissue passaging was performed, and the ovaries were stained using the hematoxylin-eosin method. Then, the ovarian tissue was evaluated by different stereological methods.

The total mean ovarian volume, the cortex volume, the medulla volume, and the corpus luteum volume, and the total number of primordial, primary, secondary, and Graafian follicles were significantly reduced in the silver nanoparticles group compared to the control group (P<0.05). The simultaneous administration of alpha lipoic acid and silver nanoparticles compensated for the adverse effects of silver nanoparticles on the above parameters. On the other hand, the mean number of different types of follicles in the rats treated with alpha lipoic acid significantly increased compared to the control group (P<0.05). A statistically significant reduction was observed in the measurement of estrogen and progesterone hormones in the serum of the silver nanoparticles group compared to the control group (P<0.05). Moreover, in assessing the antioxidant capacity of the serum of the group treated simultaneously with silver nanoparticles + alpha lipoic acid, a statistically significant increase was observed compared to the group treated with silver nanoparticles (P<0.05).

Silver nanoparticles can have adverse effects on the structure of the ovary and its components, and alpha lipoic acid can largely compensate for these detrimental effects.

Considering the increasing use of silver nanoparticles in various products, including industrial and medical products, serious worries have been created regarding the potential dangers of silver nanoparticles. This study was conducted to determine the effect of silver nanoparticles on the kidney tissues of quercetin-treated NMRI rats.

In this experimental study, 24 adult male NMRI rats were randomly divided into 4 groups of 6. The groups included the control group, the silver nanoparticles group (500 mg/kg/bw), the quercetin group (50 mg/kg/bw), and the silver nanoparticles (500 mg/kg/bw) + quercetin (50 mg/kg/bw) group. Silver nanoparticles were fed orally on a daily basis for 35 days. Quercetin was injected intraperitoneally on a daily basis for 42 days. At the end of the study, after taking blood from the rats, the dissection, tissue passaging, and Heidenhain’s Azan staining stages were carried out. The total volumes of the kidney, cortex and medulla, renal corpuscle, and glomerulus were evaluated by a stereological method. A qualitative assessment of apoptotic cells was performed using the tunnel method. The amount of malondialdehyde (MDA) in blood serum was specified as an indicator of lipid peroxidation by the Buege and Aust method.

Comparing the body weight and kidneys, and the total kidney, cortex, and medulla volumes showed no statistically significant difference between the silver nanoparticles group and the control group. The silver nanoparticles group showed a significant increase in the total mean renal corpuscle volume, glomerular volume, tuft volume, Bowman’s capsule membrane volume, and the amount of MDA compared to the control group (P<0.05). Also, a statistically significant reduction was observed in the silver nanoparticles group in the total mean volume of Bowman’s capsule and capillary spaces compared to the control group (P<0.05). Quercetin could reduce the detrimental effects of silver nanoparticles on kidney cells as much as the control group; however, apoptosis was not shown in kidney cells in the group treated with quercetin. Assessing the cells in the silver nanoparticles group indicated the creation of apoptosis. The amount of serum MDA in the silver nanoparticles group showed a statistically significant increase compared to other groups (P<0.05).

The results of this study demonstrated that quercetin could reduce the detrimental effects of silver nanoparticles on kidney cells as much as the control group.

The Qur’an as a holy book contains many truths. The importance of the Qur’an’s instructions for human health is mentioned in various verses. Pomegranate is referred to as one of the fruits of paradise whose effect on the treatment of diseases has been proven today. In addition, it has recently been used in the pharmaceutical industry.

In this study, the therapeutic effects and applications of pomegranate in medicine and pharmaceutics were investigated using scientific studies available in authentic databases.

Various parts of the pomegranate have therapeutic properties since they contain compounds such as anthocyanidins, fatty acids, vitamins, mineral salts and flavonoids. The main therapeutic properties of pomegranate are prevention and treatment of cardiovascular diseases, cancers and viral and bacterial infections. This fruit can also be used as a reducing agent in the synthesis of pharmaceutical nanoparticles as a new drug delivery system.

The evaluation of Qur’anic verses and their adaptation to new scientific knowledge have shown that pomegranate has beneficial effects on human health from various aspects, and it is recommended that clinicians and researchers in the medical and industrial fields pay attention to this fruit.

Immunocompromised persons are very susceptible to fungal infections. It is desirable to treat pulmonary fungal infections with specific delivery of drugs to the lungs.

Zein nanoparticles containing fluconazole were prepared by anti-solvent method. Their physico-chemical properties were investigated. From the optimal formulation, dry powder was prepared with lactose or mannitol using spray drying and aerosolization characteristics of the dry powders were evaluated using Anderson's cascade impactor. Antifungal effect was investigated against candida albicans and minimum inhibitory concentration was determined. Cytotoxicity of free fluconazole, dry powder containing drug loaded nanoparticles, dry powder containing nanoparticles without drug was also evaluated against A549 cell line by MTT method.

The size of nanoparticles was in the range of 88.70 ± 1.35 to 226.90 ± 5.40 nm, and the percentage of loading efficiency was in the range of 57.58 ± 3.61 to 92.94 ± 0.34. In the prepared dry powder samples, all the powder samples had a high emitted dose percentage. Cytotoxicity test showed that in general none of the groups had significant cytotoxic effects even at the highest studied concentration.

Using lactose as carrier, can improve the aerodynamic properties of dry powder compared with mannitol. The prepared inhaled fluconazole powder has a suitable fine particle fraction % and a low median mass aerodynamic diameter and can be well deposited in the lung. In addition, powder containing fluconazole was safe and its effect was comparable with fluconazole.

Today, nanoparticles have been considered an effective anti-cancer factor in cancer therapy and diagnostic studies. In this way, nanoparticles synthesized by biological methods are being developed. This study aimed to green synthesize zinc oxide nanoparticles by Bunium persicum and study toxicity and apoptotic effects in breast cancer cell lines.

Zinc oxide nanoparticles were synthesized by the fruit extract of Bunium persicum and synthesized nanoparticles were evaluated by FESEM, EDS, XRD, and Zeta sizer analyses. Then, the cytotoxicity of ZnO nanoparticles on breast cancer cell line MCF-7 and normal HEK-293 was evaluated by the MTT method within 24 hours, and the IC50 lethality was determined. Finally, P53, Bcl2, and Bax gene expression were analyzed by Real-time PCR.

ZnO nanoparticles with an average size of 100 nm and a polyhedral shape were made using the fruit extract of the Bunium persicum. According to the XRD analysis, the synthesized nanoparticles have a single-phase crystal structure and no impurities. Based on the MTT results, ZnO nanoparticles had cytotoxicity effects on cancer cells (in 16-500 µg/ml concentration) as well as normal HEK-293 cells (in 31-500 µg/ml concentration) (P<0.001). The gene expression results indicated a 2.7-fold increase in P53 (P<0.001), 6.2 in Bax, and 2.3-fold in Bcl2  (P<0.001).

The findings indicated that the fabrication of zinc oxide nanoparticles by fruit extract of Bunium persicum was done successfully. Also, these nanoparticles have toxicity effects on breast cancer cell lines, and this toxicity is probably due to the induction of apoptosis.

Theranostic nanocarriers can be used simultaneously for the diagnosis and treatment of cancer. In this study, the effect of dotarem- and doxorubicin-loaded nanodroplet as a theranostic agent for ultrasound-guided and -controlled release drug delivery on HeLa cervical cancer cells was investigated.

Folic acid-targeted nanodroplets consisting of dotarm (Gd-DOTA) and doxorubicin (DOX) with alginate shells were synthesized and characterized. In this study, HeLa and L929 cell lines were used as cancer and normal cells, respectively. Intracellular uptake of nanocarriers was evaluated using Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). Doxorubicin release in response to ultrasound exposure and its effect on cancer treatment were investigated. Ultrasound imaging was performed to assess the ultrasound signal enhancement by nanodroplets.

The characterization results confirmed the successful synthesis of nanodroplets with desirable physicochemical properties. Cytotoxicity test showed that the synthesized nanodroplets had high biocompatibility for normal cells and induced more death in cancer cells (75.3% vs 62.1%). This effect was enhanced under ultrasound exposure (51%). The ICP-OES test showed that the uptake of Gd/DOX-loaded nanodroplets for sonicated cancer cells was approximately 1.5 times higher than that for non-sonicated cells after 12 h. The results showed that the ultrasound exposure significantly increased the doxorubicin release from nanodroplets (77.5% vs 2.1%). Also, ultrasound imaging showed that perfluorohexane nanodroplets could enhance ultrasound signal intensity.

According to the results, doxorubicin- and dotarem-loaded nanodroplets with proper diagnostic and therapeutic properties can be promising theranostic agents in ultrasound-guided and controlled drug delivery for sonodynamic therapy of cancer.

In medical sciences, identifying the anticancer properties of plumbagin is of special importance. For this reason, this study investigated the anticancer activity of polymeric nanoparticles loaded by plumbagin against breast cancer cells.

In this descriptive study, the diblock copolymer mPEG–PCL was synthesized by ring-opening polymerization of caprolactone in the presence of mPEG as the initiator and Sn(oct)2 as the catalyst. The synthesized copolymers were characterized by Fourier-transform infrared spectroscopy, proton nuclear magnetic resonance, gel permeation chromatography, and differential scanning calorimetry. The nanoprecipitation method was used for preparing nanoparticles loaded with plumbagin. The characteristics of these nanoparticles were investigated by various techniques including dynamic light scattering. The cytotoxicity of plumbagin, copolymer, and the nanoparticles loaded with plumbagin on MCF7 and HFF2 cells was evaluated by MTT assay.

The average diameter of the nanoparticles was less than 115 nm. The loading capacity and encapsulation efficiencies were 15.4±0.13% and 79.1±0.65%, respectively. Drug release was slow, controlled, and almost dependent on pH. The results of the MTT assay showed strong and dose-dependent inhibition of cell growth by the plumbagin-loaded micelles compared with plumbagin alone in a way that the half maximal inhibitory concentration of this nanoparticle against MCF7 cells after 48 and 72 hours was 10.78 and 24.03 μM, respectively.

The mPEG-PCL nanoparticles can be an efficient carrier for plumbagin, and plumbagin can be an effective drug on breast cancer cells, without toxicity on healthy cells.