Substrate stiffness and topography: two powerful means for the modulation of MSCs activities!

 | Post date: 2021/06/14 | 
Substrate stiffness and topography are two powerful means by which mesenchymal stem cells (MSCs) activities can be modulated. These two physical cues act simultaneously to regulate cellular function in vessel wall. Hence it is important to investigate their cooperative effects on cellular activity. In a study conducted in 2019, the combined effects of substrate stiffness, substrate topography and culture time on the mechanical behavior of MSCs were investigated. 
Results of this study indicated that substrate topography significantly interacted with substrate stiffness as well as culture time in the modulation of cell viscoelastic behavior and smooth muscle (SM) gene expression.  According to this investigation, The micro-grooved, stiff substrates resulted in the maximum cell stiffness and gene expression of α-actin and h1-calponin, and these values were detected to be minimum in the smooth, soft substrates. 
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Cancer Vaccination: from Prevention to Treatment!

 | Post date: 2021/06/10 | 
Most of us know about vaccines given to healthy people to help prevent infections, such as measles and chicken pox. These vaccines use weakened or killed germs like viruses or bacteria to start an immune response in the body. Getting the immune system ready to defend against these germs helps keep people from getting infections. Most vaccines used to treat cancer work the same way, but they make the person’s immune system attack cancer cells. The goal is to help treat cancer or to help keep it from coming back after other treatments. But there are also some vaccines that may actually help prevent certain cancers.
Cancer immunotherapy has branched into various categories, and one of the most promising and also frustrating approaches is cancer vaccination. Vaccination has saved a million lives in the world. However, Cancer Vaccine technology has gone a long and challenging way to reach today’s place. A lot of failures in this therapy, galvanized scientists to find more efficient methods for better targeting and precise antigen and adjuvant selection. Divergent platforms and various vaccine types have been tested during the last thirty years.
Dendritic Cells, Long/Short peptides, whole tumor cell lysate, viral-based, and Genetic-based vaccines are the most common vaccine types. Novel approaches in cancer vaccination are mainly based on personalized vaccination, Nano-carrier usage, and combination therapy.
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Surface plasmon resonance (SPR): a label-free optical technique for molecular analysis

 | Post date: 2021/06/7 | 
Surface plasmon resonance (SPR) is an optical technique utilized for detecting molecular interactions. Binding of a mobile molecule (analyte) to a molecule immobilized on a thin metal film (ligand) changes the refractive index of the film. The angle of extinction of light, reflected after polarized light impinges upon the film, is altered, monitored as a change in detector position for the dip in reflected intensity (the surface plasmon resonance phenomenon). 
SPR is a label-free technique and does not require additional reagents, assays, or laborious sample preparation steps. The major benefits associated with this technique are that it simply responds to changes in refractive index induced by molecular binding events.
SPR sensors have widely spread in many application areas as they are specific, sensitive, and quantitative. Any kind of target can be detected, from small molecules such as methane, carbon dioxide, metallic ions, polycyclic aromatic hydrocarbons (PAHs), pesticides, phycotoxin, and nucleic acid up to microorganisms.
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Perianal Fistulas: The most challenging manifestations of Crohn's disease!

 | Post date: 2021/06/3 | 
Mesenchymal stem cells have been proposed as a novel, minimally invasive, well-tolerated, and alternative option in the treatment of Crohn’s fistula. In this regard, in a clinical trial that had been done in Iran, researchers showed MSCs improve refractory perianal fistula in Crohn's disease. 
Perianal fistulas in Crohn’s disease are one of the main challenges in inflammatory bowel diseases (IBDs). Some of the fistulas are refractory to any therapeutic strategy. The aim of this study was to evaluate the therapeutic effect of MSCs as a novel promising modality for the treatment of fistulizing Crohn's disease.
This case series clinical interventional study was conducted from 2014 to 2017 at Shariati hospital, an IBD referral center in Tehran, Iran. In total, 5 patients (2 males and 3 females) enrolled in this study. There were no observed adverse events during the six-month follow-up. Both the Crohn’s Disease Activity Index (CDAI) and Perianal Disease Activity Index (PDAI) scores decreased in all patients after the cell injection.
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Green Fluorescent Protein

 | Post date: 2021/05/31 | 
Green fluorescent protein (GFP) is a protein in the jellyfish Aequorea Victoria that exhibits green fluorescence when exposed to light. The protein has 238 amino acids, three of them (Numbers 65 to 67) form a structure that emits visible green fluorescent light. In the jellyfish, GFP interacts with another protein, called aequorin, which emits blue light when added with calcium. Biologists use GFP to study cells in embryos and fetuses during developmental processes.
Biologists use GFP as a marker protein. GFP can attach to and mark another protein with fluorescence, enabling scientists to see the presence of the particular protein in an organic structure. GFP refers to the gene that produces green fluorescent protein. Using DNA recombinant technology, scientists combine the GFP gene to another gene that produces a protein that they want to study, and then they insert the complex into a cell. If the cell produces the green fluorescence, scientists infer that the cell expresses the target gene as well. Moreover, scientists use GFP to label specific organelles, cells, tissues. As the GFP gene is heritable, the descendants of labeled entities also exhibit green fluorescence.
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Four-dimensional bioprinting: the next-generation solution of tissue engineering!

 | Post date: 2021/05/27 | 
Four-dimensional (4D) bioprinting, in which the concept of time is integrated with three-dimensional (3D) bioprinting as the fourth dimension, has currently emerged as the next-generation solution of tissue engineering as it presents the possibility of constructing complex, functional structures. 4D bioprinting can be used to fabricate dynamic 3D-patterned biological architectures that will change their shapes under various stimuli by employing stimuli-responsive materials.
In 2014, Skylar Tibbits, the director of the Self-Assembly Lab at the Massachusetts Institute of Technology (MIT), first demonstrated four-dimensional (4D) printing as a technology entailed multi-material prints with the capability to transform over time, or a customized material system that can change from one shape to another. This technology has been quickly applied to the field of tissue engineering, the concept of time can be integrated within 3D bioprinting technology as the fourth dimension, leading to the development of 4D bioprinting. By using stimuli-responsive materials, 4D bioprinting can be used to fabricate various 3D designed biologically active architectures capable of dynamic configuration transformations in response to different desired stimuli over time, addressing the limitations of 3D bioprinting.
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Fourier Transform Infrared Spectroscopy

 | Post date: 2021/05/24 | 
Fourier transform infrared spectroscopy (FTIR) is a technique which is used to obtain infrared spectrum of absorption, emission, and photoconductivity of solid, liquid, and gas.
FTIR identifies the presence of organic and inorganic compounds in the sample. Depending on the infrared absorption frequency range 600–4000 cm−1, the specific molecular groups prevailing in the sample will be determined through spectrum data in the automated software of spectroscopy.
A typical FTIR spectrometer includes a source, sample cell, detector, amplifier, A/D convertor, and a computer. Radiation from the sources reach the detector after it passes through the interferometer. The signal is amplified and converted to a digital signal by the A/D convertor and amplifier, after which the signal is transferred to the computer where the Fourier transform is carried out. 
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CAR T-cell Therapy: The changing the landscape of hematology and oncology!

 | Post date: 2021/05/20 | 
Chimeric antigen receptor (CAR) T cells directed against the B-cell marker CD19 are currently changing the landscape for treatment of patients with refractory and/or relapsed B-cell malignancies such as pediatric and adult acute lymphoblastic leukemia (ALL), non-Hodgkin lymphoma (NHL) and chronic lymphocytic leukemia (CLL). Due to the nature of CAR T cells as living drugs, they display a unique toxicity profile. As CAR T-cell therapy is extending towards other diseases and being more broadly employed in hematology and oncology, optimal management strategies of side-effects associated with CAR T-cell therapy are of high relevance. Cytokine release syndrome (CRS), immune effector cell-associated neurotoxicity syndrome (ICANS), and cytopenias constitute challenges in the treatment of patients with CAR T cells.
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Perspectives on Cold Atmospheric Plasma in cancer treatment!

 | Post date: 2021/05/17 | 
Plasma medicine is an innovative research field combining plasma physics, life science, and clinical medicine. It is mainly focused on the application of cold atmospheric plasma (CAP) in therapeutic settings. Cold atmospheric plasma (CAP) is a potential anticancer therapy. CAP has cytotoxic effects when applied either directly to cancer cell cultures or indirectly through plasma-conditioned liquids. The latest research published by Nature introduces a novel protocol after the evaluation of the effect of CAP and plasma-treated liquids in cancer cell cultures. This protocol describes how to treat adherent cultures of human cancer cell lines with CAP or plasma-conditioned medium and determine cell viability following treatment. The protocol also includes details on how to quantify the reactive oxygen and nitrogen species present in medium following CAP treatment, using chemical probes using UV-visible or fluorescence spectroscopy. CAP treatment takes ~30 min, and 3 h are required to complete quantification of reactive oxygen and nitrogen species. By providing a standardized protocol for evaluation of the effects of CAP and plasma-conditioned medium, we hope to facilitate the comparison and interpretation of results seen across different laboratories.
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A small-molecule cocktail promotes cytoprotection and viability of human pluripotent and differentiated cells!

 | Post date: 2021/05/13 | 
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Western blotting: important technique in cell and molecular biology!

 | Post date: 2021/05/10 | 

A western blot is a laboratory method used to detect specific protein molecules from among a mixture of proteins. This mixture can include all of the proteins associated with a particular tissue or cell type. Western blots can also be used to evaluate the size of a protein of interest, and to measure the amount of protein expression. This procedure was named for its similarity to the previously invented method known as the Southern blot.

The first step in a western blot is to prepare the protein sample by mixing it with a detergent called sodium dodecyl sulfate, which makes the proteins unfold into linear chains and coats then with a negative charge. Next, the protein molecules are separated according to their sizes using a method called gel electrophoresis. Following separation, the proteins are transferred from the gel onto a blotting membrane. Although this step is what gives the technique the name "western blotting," the term is typically used to describe the entire procedure.

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SARS-CoV-2 Variant Classifications and Definitions!

 | Post date: 2021/05/6 | 
The novel respiratory disease COVID-19 has reached the status of worldwide pandemic and large efforts are currently being undertaken in molecularly characterizing the virus causing it, SARS-CoV-2. The genomic variability of SARS-CoV-2 specimens scattered across the globe can underly geographically specific etiological effects. Italian scientists analyzed and annotated all SARS-CoV-2 mutations compared with the reference Wuhan genome NC_045512.2, observing an average of 7.23 mutations per sample. Their analysis shows the prevalence of single nucleotide transitions as the major mutational type across the world. SARS-CoV-2 is a single-stranded RNA beta-coronavirus with a compact 29,903 nucleotides-long genome. Genetic variance analyses must now play a crucial role in expanding knowledge on this new virus to adopt measures to contain its outbreak. The existing detected mutations allow to group the samples into five distinct clades, G, GH, GR, S, and V, characterized by a collection of specific mutations. The clades can be further characterized by the most recent mutations and will likely be split even further in the future.
Moreover, the Centers for Disease Control and Prevention (CDC) released an update on MAY 5 2021, about SARS-CoV-2 variant classifications and definitions which shows that genetic variants of SARS-CoV-2 have been emerging and circulating around the world throughout the COVID-19 pandemic. 
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Gas chromatography: common type of chromatography used in analytical chemistry!

 | Post date: 2021/05/3 | 
Modern gas chromatography (GC) was invented by Martin and James in 1952 [1], and has become one of the most important and widely applied analytical techniques in modern chemistry. Major milestones in the development of GC, especially in column technology, detection and sample introduction are described in this historical review. Many trends in current progress can be seen to originate in the first two decades of the history of GC, but the invention of fused-silica capillary columns greatly increased the application of high-resolution GC across the field of organic analysis; the development of low-cost, bench-top mass spectrometers led to further advances. Progress continues to be rapid in comprehensive 2D GC, fast analysis, detection by atomic emission and time-of-flight mass spectrometry, and in applications to process analysis.
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Hydrogel dressings: Inspiration for diabetic wound treatment!

 | Post date: 2021/04/30 | 
Wounds are injuries that break the skin, leading to disruption of its normal anatomic structure and function. Wound healing is a dynamic and complex process. Hydrogels are three-dimensional (3D) networks consisting of physically or chemically cross-linked bonds of hydrophilic polymers. The insoluble hydrophilic structures demonstrate a remarkable potential to absorb wound exudates and allows oxygen diffusion to accelerate healing. Importantly, hydrogels possess a highly hydrated 3D polymeric network and can bind several-fold more water as compared to their dry weight and can thereby maintain a high moisture level of the wound bed. Due to these unique physical properties, hydrogel networks can be casted into various sizes and shapes. Therefore, hydrogel-based materials are the most suitable dressings to cover skin wounds. Furthermore, hydrogels offer a platform to load cells, antibacterial agents, growth factors, as well as distinct supplementary and biomacromolecules. With regard to ECM similarity, hydrogels used for wound healing applications should provide a cell-friendly 3D environment to promote tissue regeneration, with or without the presence of cells embedded in the scaffold. Importantly, all hydrogels need to satisfy the basic requirements of biocompatibility in clinical use as well as possess unique physical and mechanical properties suited for skin wound applications. Moreover, they also need to provide the appropriate microenvironment for vessel ingrowth and cellular proliferation.
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Electrophoresis: Chromatography technique

 | Post date: 2021/04/26 | 
Electrophoresis is a chromatography technique by which a mixture of charged molecules is separated according to size when placed in an electric field. 
Electrophoresis is a general term that describes the migration and separation of charged particles (ions) under the influence of an electric field. An electrophoretic system consists of two electrodes of opposite charge (anode, cathode), connected by a conducting medium called an electrolyte. The separation effect on the ionic particles results from differences in their velocity (v), which is the product of the particle's mobility (m) and the field strength (E):
v=mE
The mobility (m) of an ionic particle is determined by particle size, shape, and charge, and the temperature during the separation, and is constant under defined electrophoretic conditions.
 The ability of electrophoresis to separate charged species ranges from small inorganic or organic ions to charged biopolymers (like DNA or proteins), or even chromosomes, microorganisms, or whole cells.
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Portable Bioprinters: Facilitating and Accelerating Regenerative Medicine!

 | Post date: 2021/04/22 | 
Bioprinting technologies have been advancing at the convergence of automation, digitalization, and new tissue engineering (TE) approaches. In situ bioprinting may be favored during certain situations when compared with the conventional in vitro bioprinting when de novo tissues are to be printed directly on the intended anatomical location in the living body. 
The portable bioprinting approach involves a thoroughly portable device that allows the deposition of bio-inks (biomaterials and cells) in a direct-write fashion. The portable bioprinter has many advantages such as ease of use and high speed. However, the most prominent advantage of portable bioprinters is that the operator can hold the bioprinter to print bio-ink directly at the wound site, without needing a computer system and defect scanning. 
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Flow Cytometry: Basic Principles

 | Post date: 2021/04/19 | 
Flow cytometry is a technology that provides rapid multi-parametric analysis of single cells in solution. Flow cytometers utilize lasers as light sources to produce both scattered and fluorescent light signals that are read by detectors such as photodiodes or photomultiplier tubes. These signals are converted into electronic signals that are analyzed by a computer and written to a standardized format (.fcs) data file. Cell populations can be analyzed and/or purified based on their fluorescent or light scattering characteristics. A variety of fluorescent reagents are utilized in flow cytometry. These include, fluorescently conjugated antibodies, DNA binding dyes, viability dyes, ion indicator dyes, and fluorescent expression proteins.
The instrumentation used for flow cytometry has evolved over the last several decades. Multiple laser systems are common as are instruments that are designed for specific purposes, such as systems with 96-well loaders designed for bead analysis, systems that combine microscopy and flow cytometry and systems that combine mass spectrometry and flow cytometry.
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Mesenchymal stem cells: immunomodulation and regenerative properties cooperate against COVID-19!

 | Post date: 2021/04/15 | 
Human umbilical cord-derived mesenchymal stem cells (UC-MSCs) have been proposed that are effective in the regeneration of damaged lungs in severe COVID-19 patients. In this regard, In a randomized, double-blind, placebo-controlled phase 2 trial, Shi et al. illustrated that UC-MSCs treatment is a safe and potentially effective therapeutic approach for COVID-19 patients with lung damage. 
Mesenchymal stem cells (MSCs) are non-hematopoietic cells with immune-modulatory, regenerative, and differentiation properties. And their efficacy as a therapeutic method against pathological changes of the lung induced by the influenza virus. moreover, The safety and potential efficacy of MSC have also been evaluated in patients with acute respiratory distress syndrome (ARDS). The immunomodulatory and regenerative properties of MSCs offer a potential cellular therapeutic option for lung damage in patients with COVID-19.
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Nested Polymerase Chain Reaction!

 | Post date: 2021/04/12 | 
Nested polymerase chain reaction (Nested PCR) is a modification of PCR that was designed to improve sensitivity and specificity. This technique reduces nonspecific amplification of the DNA template. Nested PCR involves the use of two primer sets and two successive PCR reactions. The first set of primers are designed to anneal to sequences upstream from the second set of primers and are used in an initial PCR reaction. The first reaction is performed with primers that cover the target sequence and some additional sequence flanking both ends of the target sequence. After the first reaction, a second reaction is performed on the products of the first PCR with primers that bind to the target sequence and are within the amplified sequence of the first PCR. This reduces the amount of nonspecific binding because in the second reaction, most of the amplicons of the first reaction only contain the target sequence and its surrounding sequences.
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Decellularization: paving the way for whole heart tissue engineering!

 | Post date: 2021/04/8 | 
Decellularized extracellular matrices (dECMs) from mammalian tissues and organs as scaffolds have revolutionized tissue engineering by their ability to retain chemical compositions and three-dimensional microstructures that are similar to native ECMs. These bioscaffolds are subsequently repopulated with patient‐derived cells, thus constructing a personalized neo‐organ and ideally eliminating the need for immunosuppression. The technique of de‐ and recellularization has achieved substantial advances in the field of organ bioengineering.
Among different organs and tissues, whole heart tissue engineering has remained a challenge due to its architecture and biochemistry. The field of whole heart tissue engineering has been revolutionized since the 2008 publication of the first perfusion-decellularized whole heart. A decellularized heart composed of native extracellular matrix has been shown to offer a complex, unique, and natural scaffold that provides both physical and chemical cues required for cardiac function.
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