sahar jahangiri

Recent advances in the development of magnetic nanoparticles modified with biodegradable polymers have shown promise in the improvement of therapeutic approaches for the clinical management of cancer patients. In this study, polycaprolactone -polyethylene glycol – polycaprolactone (PCL-PEG-PCL) copolymers modified with magnetic nanoparticles were used for encapsulation of doxorubicin (DOX) and chrysin (Chr) anticancer drugs by dual emulsion (W / O / W). The effect of temperature and pH on drug release was investigated. The release of the doxorubicin drug in pH 7.4 and 5.8 were 26.5% and 30.6%, respectively after 144 h. In chrysin drug, the release of drug in pH 7.4 and 5.8 was equal to 45% and 49%, respectively after 144 h. The kinetics of the drug's release was also studied based on zero-order, first-order, Higuchi, and Korsmeyer-Peppas models. From the kinetic models, based on the correlation coefficient, Higuchi (R2=0.9017) and Korsmeyer-Peppas (R2=0.9639) models were found to be the best models for doxorubicin and chrysin, respectively. After performing kinetic studies, the diffusion coefficient of drug release was also studied. The drug distribution was considered uniform, and the system was investigated in Cartesian and spherical coordinates. The results showed that the diffusion coefficient of drug release followed Fick's law. The diffusion coefficient decreased with increasing time due to decreasing the concentration difference.

 The aim of this in vitro study was to assess the quantity of nickel and chromium ions released from orthodontic wires when subjected to various beverage solutions and distilled water.

 Orthodontic appliances composed of five brackets, one band and 0.016-inch stainless steel and nickel titanium wires were immersed in Coke, tea, coffee and distilled water. The samples were incubated at 37℃ for 1 hour, 6 hours, 24 hours, and one week. There was a total of 120 appliances divided into 24 groups (n=5 in each group). Atomic absorption spectroscopy was used to examine the amount of released ions. Two-way and one-way ANOVA followed by Tukey test were used for statistical analysis and P<0.05 was considered significant.

 The release of nickel ions from both wires was highest in Coke and lowest in distilled water at all time points. Coffee and tea demonstrated values in-between these two limits. Similarly, chromium ion release from both wires was highest in Coke at all time-points compared to all other solutions (P<0.05). None of the other tested drinks showed significant differences in chromium ion release compared to distilled water.

 Restricting the intake of acidic drinks, particularly carbonated beverages like Coke, plays a critical role in safeguarding orthodontic wire components. Educating patients and providing dietary guidelines are essential for maximizing treatment effectiveness. Further research is required to investigate additional factors impacting ion release and devising methods to mitigate potential harm.

In recent years, the development of nanoparticles has received much attention in the controlled drug release and biomedicine fields. This research aims to develop new methods for the physical modification of Fe3O4 superparamagnetic nanoparticles with polymers through physical retention. In this study, first, the degradable polycaprolactone-ethylene glycol copolymer and magnetic nanoparticles were synthesized. The anticancer drug doxorubicin was prepared using a dual-emulsion (w/o/w) copolymer containing magnetic iron nanoparticles. FT-IR, NMR, XRD, VSM, and, SEM analyzes were used to characterize copolymers and magnetic nanoparticles with drug-containing copolymer coating. The results showed that nanoparticles had superparamagnetic properties and their particle size was between 70-150 nm. The drug encapsulation efficiency was about 96%. The influence of pH and temperature on the drug release curve was investigated. The drug release was 31% and 26% after 144 hours in pH = 5.8 and 7.4 respectively. Since the extracellular fluid of the tumor is acidic, the rate of drug release in these media will be better than in other cells. The kinetics of the drug release was also studied based on zero-order, first-order, Higuchi and Korsmeyer-Peppas models. From the kinetic models, Higuchi was found to be the best model based on the correlation coefficient. The performance of the drug-loaded magnetic-copolymer nanoparticles with other similar studies was compared. The results revealed that the magnetic PCL-PEG copolymer with pH-sensitive properties can be used as an effective carrier for anticancer drugs delivery.

Iron oxide nanoparticles are smart materials that have been commonly used in medicine for diagnostic imaging, drug delivery, and therapeutic applications. In this study, Iron oxide nanoparticles and Doxorubicin (DOX)- Chrysin (Chr), were absorbed into triblock copolymer (PCL-PEG-PCL) for narrow behavior. PCL-PEG triblock copolymers were synthesized by ring-opening polymerization of ε-caprolactone (ε-CL) with polyethylene glycol (EG) as an initiator. The bulk properties and chemical structure of these copolymers were characterized using Fourier transform infrared spectroscopy and 1H-NMR. In adding together, the consequential particles were characterized by scanning electron microscopy, X-ray powder diffraction, vibrating sample magnetometry, and zeta potential measurement. Response surface methodology (RSM) was employed to study the effects of the three most important parameters on encapsulation efficiency, namely DOX and Chr weight (2-18 mg), ε -CL weight (0.6-3.8 g), and sonication time (15-75s). The optimum encapsulation conditions were: 11.2 mg for DOX and Chr weight, 3.75 g for ε -CL, and 48.15 s for sonication time. The highest encapsulation efficiency in these conditions predicted by the equation is 95.68% and the release profile was controlled. There is potential for the application of Fe3O4- PCL-PEG4000 magnetic nanoparticles for biomedical purposes.

In recent years, the development of nanoparticles in the field of drug release has received much attention. This research aims to develop new methods for the physical modification of Fe3O4 superparamagnetic nanoparticles with polymers through physical retention. In this study, after synthesizing the biodegradable polycaprolactone-polyethylene glycol magnetic copolymer, the anticancer drugs doxorubicin and Chrysin in these polymers were encapsulated by dual emulsion (w / o / w). The effect of temperature and pH on drug release was investigated. After performing kinetic studies, the diffusion coefficient of drug release was also studied. The drug distribution was considered uniform and the system was assumed to be in Cartesian coordinates. The results showed that the diffusion coefficient of drug release followed Fick's law. At first, due to the high concentration difference of drugs in the early times, the diffusion coefficient was higher, but then with time and with decreasing the concentration difference, the diffusion coefficient decreased and remained constant.

All metal components of orthodontic appliances are somewhat corroded in the oral environment due to some changes in chemical, mechanical, thermal, microbiological and enzymatic factors which facilitates ion release. Ionic release can result in a discoloration of the surrounding soft tissue or allergic reactions in sensitive patients or even local pain in the area. In general, ions can cause toxic and biological side effects if their values reach the threshold, so the release of ions from the metal components of orthodontic appliances is important to us. The aim of this review article to determine the rate of orthodontic appliances ion release in different solutions.

A review of the literature was carried out in Pubmed, Google Scholare and Web of science database using selected key words (Saliva/ Titanium/Normal Saline/ Ion release Orthodontic appliance/Mouth wash/ Nickel/ Chromium). These searches were limited to the articles published from 2005 to 2018. According to the inclusion and exclusion criteria, 25 articles were obtained.

Because of conflicts in the reported results, it was necessary to synchronize the measurement methods and also to use artificial saliva medium with normal pH as a control to achieve better systematic comparison.

There was significant differences in the ion release between mouthwashes. In all studies, the effect of pH and acidity has been shown to increase the release of these ions. In addition, stainless steel (SS) instruments had the least biocompatibility among all types of alloys evaluated.

Attempts for early detection of gastric cancer have recently focused on host''s genetic susceptibility factors and gene-environment interactions. We have، herein، studied the association of MTHFR C677T single nucleotide polymorphism (SNP) and its interaction with Helicobacter pylori infection، smoking، age and gender on the risk of gastric cancer among an Iranian population. Gastric cancer patients (n = 450) and cancer-free controls (n = 780) were studied for serum H. pylori-specific IgG antibodies by ELISA and MTHFR C677T polymorphism (SNP) by PCR-RFLP. Demographic and life style data were collected through patient interviews. Unconditional logistic regression model estimated odds ratio (OR) and the corresponding 95% confidence intervals (CI). The interactions of MTHFR genotype with H. pylori infection (P = 0. 03)، age (P = 0. 049) and gender (P = 0. 007) were statistically significant. Accordingly، MTHFR C677T carriers who were also positive for H. pylori infection exhibited 80% (OR = 1. 8، 95% CI = 1. 0-2. 9) significant excess risk of non-cardia gastric cancer. Furthermore، subjects over the age of 50 or female subjects carrying MTHFR C677T SNP showed 40 (OR = 1. 4، 95% CI = 1. 0-2. 0) and 100 (OR = 2. 0، 95% CI = 1. 2-3. 2) percent increased risk of gastric cancer، respectively. Therefore، MTHFR C677T SNP seems to increase the risk of gastric cancer and the effect is significantly inflated by interactions with H. pylori infection، age and gender.

The most prevalent complication of gallstone is chronic cholecystitis. The aim of the present study was to determine the responsible microorganisms in patients undertook cholecystectomy and determine their antibiotic resistance pattern. Cholecystectomy was achieved in 100 patients. Collected samples transferred to laboratory in appropriate media, then cultured on selective media to isolate the possible causative bacteria. Antibiotic susceptibility tests were also performed by Kirby-Baur method with a colony in Muller-Hinton agar medium. Totally, 63 samples showed bacterial growth, of which 11 revealed two species of bacteria. A total of 10 gram positive (enterococci and staphylococci) and 63 gram negative (E.coli, klebsiella, aerobacter, pseudomonas, proteus, citrobacter, providencia and acinetobacter) bacteria were isolated. Isolating bacteria and determining their susceptibility to different antibiotics may help physicians to manage cholecystitis and its associated complications.