Numerical Analysis of the Reaction-diffusion Equation for Soluble Starch and Dextrin as Substrates of Immobilized Amyloglucosidase in a Porous Support by Using Least Square Method

Substrates' concentration profile was studied in a porous matrix containing immobilized amyloglucosidase for glucose production. This analysis was performed by using an analytical method called Least Square Method, and the results were compared with numerical solution. Effects of effective diffusivity, Michael's constant, maximum reaction rate and initial substrate concentration were studied on Soluble Starch and Dextrin concentration in the spherical support. The outcomes revealed that Least Square Method has an excellent agreement with numerical solution, and in the center of support, substrate concentration is minimum. Increasing of effective diffusivity and Michael's constant reduced the Soluble Starch and Dextrin profile gradient

Pseudomonas aeruginosa biosurfactant production in culture with glucose as carbon source

A rhamnolipid producing bacterium, P.aeruginosa MM1011 was previously isolated from crude oil over years. Isolated strain was identified by morphological, biochemical, physiological and 16srRNA (1). The identified Pseudomonas aeruginosa confirmed by Persian Type Culture Collection (PTCC idendification confirmation report No.1011). Glycolipid production by isolated bacterium using sugar beet molasses as a carbon and energy source was investigated.MM1011, was used for the development of a continuous process for biosurfactant production. The active compounds were identified as rhamnolipids. A final medium for production was designed in continuous culture by means of medium shifts, since the formation of surface-active compounds was decisively influenced by the composition and concentration of the medium components. In the presence of yeast extract, biosurfactant production was poor. For the nitrogen-source nitrate, which was superior to ammonium, an optimum carbon-to-nitrogen ratio of ca. 18 existed. The iron concentration needed to be minimized to27.5μg of FeSO4.7H20 per g of glucose. A carbon-to-phosphate ratio,Şc/p= 20, obtained the maximum production of rhamnolipids. The final productivity dilution rate diagram indicated that biosurfactant production was correlated to low growth rates (dilution rate below 0.18 h−1). With a medium containing 24.2 gr of glucose γl-1, a biosurfactant concentration (expressed as rhamnolipids) of up to 1.1 gr γl-1 was obtained in the cell-free culture liquid. The rhamnolipid mass concentration was 7.5 mg ml-1 and surface tension was reduced to 20 mN m-1

\u3cem\u3eIn vitro\u3c/em\u3e Effect of Graphene Structures as an Osteoinductive Factor in Bone Tissue Engineering: A Systematic Review

Graphene and its derivatives have been well‐known as influential factors in differentiating stem/progenitor cells toward the osteoblastic lineage. However, there have been many controversies in the literature regarding the parameters effect on bone regeneration, including graphene concentration, size, type, dimension, hydrophilicity, functionalization, and composition. This study attempts to produce a comprehensive review regarding the given parameters and their effects on stimulating cell behaviors such as proliferation, viability, attachment and osteogenic differentiation. In this study, a systematic search of MEDLINE database was conducted for in vitro studies on the use of graphene and its derivatives for bone tissue engineering from January 2000 to February 2018, organized according to the PRISMA statement. According to reviewed articles, different graphene derivative, including graphene, graphene oxide (GO) and reduced graphene oxide (RGO) with mass ratio ≤1.5 wt % for all and concentration up to 50 μg/mL for graphene and GO, and 60 μg/mL for RGO, are considered to be safe for most cell types. However, these concentrations highly depend on the types of cells. It was discovered that graphene with lateral size less than 5 µm, along with GO and RGO with lateral dimension less than 1 µm decrease cell viability. In addition, the three‐dimensional structure of graphene can promote cell‐cell interaction, migration and proliferation. When graphene and its derivatives are incorporated with metals, polymers, and minerals, they frequently show promoted mechanical properties and bioactivity. Last, graphene and its derivatives have been found to increase the surface roughness and porosity, which can highly enhance cell adhesion and differentiation

Chitosan/Agarose/Graphene oxide nanohydrogel as drug delivery system of 5-fluorouacil in breast cancer therapy

Breast cancer refers to a very common deadly class of malignant tumors, especially in women worldwide. In the present study, a promising methodology has been developed to simultaneously improve the drug loading per-formance and achieve a sustained release of 5-fluorouracil (5-FU) as a model drug for breast cancer. For this purpose, a pH-sensitive and biocompatible hydrogel of chitosan/agarose/graphene oxide (CS/AG/GO) was first synthesized with glyoxal as cross-linker. 5-FU-loaded nanocomposites (NCs) of CS/AG/GO were then prepared via water-in-oil-in-water (W/O/W) emulsification technique. XRD and FTIR analyses confirmed the successful synthesis of the nanocarriers and gave insight on their crystalline structure and molecular interactions between the components. DLS demonstrated that the nanocarriers comprise nanoparticles with an average size of 197 nm and a PDI of 0.34. SEM revealed their spherical morphology and zeta potential measurements indicated an average surface charge of +23.5 mV. The drug loading and entrapment efficiencies (57% and 92%, respectively) were significantly higher than those reported previously for other nanocarriers. A very effective and sustained drug release profile was observed at pH 5.4; in 48 h, almost the entire 5-FU content was released. Moreover, effective cytotoxicity against breast cancer cell (BCC) lines (MCF-7) was observed: the cell viability upon in-cubation with CS/AG/GO/5-FU was about 23%, demonstrating its anti-cancer capability. Therefore, the syn-thesized NCs can potentially act as pH-sensitive nanovehicles for programmed release of 5-FU in breast cancer treatment.Comunidad de Madri

Chitosan/Gamma-Alumina/Fe3O4@5-FU nanostructures as promising nanocarriers: physiochemical characterization and toxicity activity

Today, cancer treatment is an important issue in the medical world due to the challenges and side effects of ongoing treatment procedures. Current methods can be replaced with targeted nano-drug delivery systems to overcome such side effects. In the present work, an intelligent nano-system consisting of Chitosan (Ch)/Gamma alumina (gamma Al)/Fe3O4 and 5-Fluorouracil (5-FU) was synthesized and designed for the first time in order to influence the Michigan Cancer Foundation-7 (MCF-7) cell line in the treatment of breast cancer. Physico-chemical characterization of the nanocarriers was carried out using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), vibrating sample magnetometry (VSM), dynamic light scattering (DLS), and scanning electron microscopy (SEM). SEM analysis revealed smooth and homogeneous spherical nanoparticles. The high stability of the nanoparticles and their narrow size distribution was confirmed by DLS. The results of the loading study demonstrated that these nano-systems cause controlled, stable, and pH-sensitive release in cancerous environments with an inactive targeting mechanism. Finally, the results of MTT and flow cytometry tests indicated that this nano-system increased the rate of apoptosis induction on cancerous masses and could be an effective alternative to current treatments

Patterns of better breast cancer care in countries with higher human development index and healthcare expenditure : Insights from GLOBOCAN 2020

Funding Information: The authors would like to thank the International Agency for Research on Cancer and the World Health Organization for their efforts on cancer epidemiology estimates, as well as the GLOBOCAN project, which made this study possible. Publisher Copyright: Copyright © 2023 Azadnajafabad, Saeedi Moghaddam, Mohammadi, Delazar, Rashedi, Baradaran and Mansourian.Peer reviewedPublisher PD

Construction of Aptamer-Based Nanobiosensor for Breast Cancer Biomarkers Detection Utilizing g-C3N4/Magnetic Nano-Structure

An electrochemical aptasensor has been developed to determine breast cancer biomarkers (CA 15-3). Aptamer chains were immobilized on the surface of the electrode by g-C3N4/Fe3O4 nanoparticles, which increased the conductivity and active surface area of the electrode. X-ray diffraction analysis (XRD), Fourier-transformed infrared spectroscopy (FTIR), and transmission electron microscopy (TEM) measurements have been carried out to characterize the nanomaterials. Cyclic voltammetry, square wave voltammetry, and electrochemical impedance spectroscopy have been used to characterize the developed electrode. The results demonstrate that the modified electrode has better selectivity for CA 15-3 compared to other biological molecules. It has a good electrochemical response to CA 15-3 with a detection limit of 0.2 UmL(-1) and a linear response between 1 and 9 UmL(-1). It has been used as a label-free sensor in potassium ferrocyanide medium and as methylene blue-labeled in phosphate buffer medium. This electrode was successfully applied to analyze the serum of diseased and healthy individuals, which corroborates its high potential for biosensing applications, especially for the diagnosis of breast cancer

Patterns of better breast cancer care in countries with higher human development index and healthcare expenditure: Insights from GLOBOCAN 2020

BackgroundThe huge burden of breast cancer (BC) necessitates the profound and accurate knowledge of the most recent cancer epidemiology and quality of care provided. We aimed to evaluate BC epidemiology and quality of care and examine the effects of socioeconomic development and healthcare expenditure on disparities in BC care.MethodsThe results from the GLOBOCAN 2020 study were utilized to extract data on female BC, including incidence and mortality numbers, crude rates, and age-standardized rates [age-standardized incidence rates (ASIRs) and age-standardized mortality rates (ASMRs)]. The mortality-to-incidence ratio (MIR) was calculated for different locations and socioeconomic stratifications to examine disparities in BC care, with higher values reflecting poor quality of care and vice versa. In both descriptive and analytic approaches, the human development index (HDI) and the proportion of current healthcare expenditure (CHE) to gross domestic product (CHE/GDP%) were used to evaluate the values of MIR.ResultsGlobally, 2,261,419 (95% uncertainty interval (UI): 2,244,260–2,278,710) new cases of female BC were diagnosed in 2020, with a crude rate of 58.5/100,000 population, and caused 684,996 (675,493–694,633) deaths, with a crude rate of 17.7. The WHO region with the highest BC ASIR (69.7) was Europe, and the WHO region with the highest ASMR (19.1) was Africa. The very high HDI category had the highest BC ASIR (75.6), and low HDI areas had the highest ASMR (20.1). The overall calculated value of female BC MIR in 2020 was 0.30, with Africa having the highest value (0.48) and the low HDI category (0.53). A strong statistically significant inverse correlation was observed between the MIR and HDI values for countries/territories (Pearson's coefficient = −0.850, p-value < 0.001). A significant moderate inverse correlation was observed between the MIR and CHE/GDP values (Pearson's coefficient = −0.431, p-value < 0.001).ConclusionsThis study highlighted that MIR of BC was higher in less developed areas and less wealthy countries. MIR as an indicator of the quality of care showed that locations with higher healthcare expenditure had better BC care. More focused interventions in developing regions and in those with limited resources are needed to alleviate the burden of BC and resolve disparities in BC care