سارا رجبی

Treatment of bone defects is very challenging due to the complex composition, structure, and functions of bone. Tissue engineering is a new approach to the treatment of bone injuries. In this study, bone marrow mesenchymal stem cells (BMSCs) were extracted from rat tibia and femur and cultured in αMEM medium. Then, morphology, surface markers, and differentiation into bone and fat cells were evaluated. The sheep heart tissue was cut into pieces and decellularized with 1% SDS and then examined by tissue-specific staining (hematoxylin-eosin, Masson's trichrome, DAPI, and Alcian blue). Cardiogel was prepared from the decellularized cardiac muscle tissue and then a two-dimensional coating derived from cardiogel was created. To investigate the viability, proliferation, and differentiation, BMSCs were cultured on different concentrations (0.05, 0.1, 0.2, 0.4, and 0.8) of cardiogel coating which was used as the test group. The gelatin coating was used as a positive control group and the substrate without any coatings was used as a negative control group. Increased viability, proliferation, and differentiation of BMSCs were observed in culture vessels containing cardiogel. According to the results of the cell viability examination, with the increase in the concentration of cardiogel, the growth and the function of the cells increased; However, it was not statistically significant. The results of this study showed that cardiogel can be used as a two-dimensional coating in cell culture and provide a microenvironment similar to the inside of the body.

The purpose of the present study was to investigate the effect of aerobic-resistance training on the population of cardiac multipotent cells, thickness, and diameter of the ventricular through the C-Kit pathway of male rats during the growth stages.

Overall, 30 male Wistar rats in three age groups of 2 (n = 10), 8 (n = 10), and 96 (n = 10) weeks were accidentally divided into exercise and control groups. Resistance training programs (resistance ladder, 3 days a week) and aerobics (treadmill running, 3 days a week) were performed for 6 weeks. Hematoxylin-Eosin staining was done the heart tissue and histological images were prepared. Afterward, C-Kit gene expression was examined by the real-time polymerase chain reaction method. The statistical method of one-way analysis of variance (P ≥ 0.05) and Tukey’s test were used at a significant level (P ≥ 0.01).

The trained neonatal group had higher values in heart weight to body weight index, and the trained neonatal and trained young adult groups had higher values in left ventricular thickness (P ≥ 0.01). The decrease in left ventricular internal diameter in the trained young adult group was significant compared to the control group (P ≥ 0.01). There was a significant increase in C-Kit gene expression in trained young adult and trained old groups (P ≥ 0.01).

Aerobic-resistance training can be an effective stimulus for increasing the number of cardiac stem cells and creating structural adaptations of the heart, including increasing thickness and ventricular diameter in neonatal and young adult groups.

Participation in aerobic-resistance training programs leads to the improvement of the cardiac structure and an increase in cardiac stem cells.

The evidence indicates that exercise training can affect the heart's structure at the cellular-molecular levels. Therefore, this study aimed to investigate the effect of exercise training on miR-222 and the expression of cTnT, Cx43 genes, and cardiomyocyte proliferation in pre-pubertal, young adult, and old male rats.

The number of 30 male Wistar rats in three age groups; 2 weeks as the pre-pubertal group, 8 weeks as the young group, and 96 weeks as the old group were randomly divided into two training groups (n=5), and control (n=5). Resistance training programs (resistance ladder, 3 days per week) and aerobic (treadmill running, 3 days per week) were performed for 6 weeks. The expression of miR-222 and Cx43, cTnT, and Ki67 genes were investigated by the Real Time-PCR method. One-way analysis of variance and Tukey's post hoc test were used (P≥0.05).

The amount of BrdU protein by immunohistochemical method and Ki67 gene expression was significantly higher in the training groups than in the control groups in all three age groups: pre-pubertal, young adult, and old male rats (P≥0.05). miR-222 was significantly higher in the group of trained pre-pubertal than in the control group (P=0.023). The increase in cTnT gene expression in the pre-pubertal groups (P=0.018) and old rats (P=0.015) and the increase in Cx43 gene expression in the old rats group (P=0.009) was observed.

Aerobic-resistance training can be an effective stimulus to increase cardiomyocyte proliferation in all three age groups pre-pubertal, young, and old.

Bone is the hardest and one of the most important tissues in the body. In case of bone damage, the current treatments do not completely repair and regenerate the bone. For this reason, cell-based tissue engineering strategies, especially Mesenchymal Stem Cells (MSCs), have received attention. MSCs have the ability to self-renew and differentiate into different cell types, including bone cells, cartilage cells, and fat cells, among others. They are found in various tissues throughout the body, including bone marrow, adipose tissue, and umbilical cord tissue. Today, MSCs are a valuable resource for regenerative medicine and tissue engineering applications. In addition to the cells, scaffolds are another essential element of tissue engineering. One of these scaffolds is decellularized tissue-derived hydrogels, which are three-dimensional network of hydrophilic polymer chains that can absorb and retain a significant amount of water. In tissue engineering, they mimic the natural extracellular matrix of tissues, providing a suitable environment for cells to attach, proliferate, and differentiate. In the current study, we aimed to investigate the effects of decellularized skeletal muscle-derived hydrogel, known as Myogel, on bone marrow-derived MSCs biological behaviors, including proliferation, viability and migration. In this study, MSCs were isolated from tibia and femur of adult Wistar rats. MSCs were cultured in a complete medium (a-MEM containing 15% fetal bovine serum (FBS) and 1% penicillin/streptomycin (Pen/Strep)). The identity of cells was determined by morphology (using inverted microscope) and expression of specific CD markers (using Flowcytometry). Skeletal muscle was decellularized and accuracy of decellularization was evaluated using special staining. Then Myogel was prepared from digested decellularized skeletal muscle. Here, Myogel substrate was used as the control group, gelatin substrate as the positive control, and un-coated plates as the negative control. The effect of Myogel on survival (MTT method), proliferation (drawing the growth curve and calculating the doubling time of the cell population), cell cycle profile (flow cytometry method), and cell migration (scratch method) were investigated. The MTT test showed that the survival of MSCs in Myogel substrate with a concentration of 0.2 mg/ml was higher than the survival of MSCs in gelatin substrate with a concentration of 0.1 mg/ml and the survival of MSCs in gelatin was higher than the survival of control MSCs. Myogel substrate increased the proliferation and migration of cells and decreased the doubling time of MSCs population. Examining the cell cycle profile showed that a high percentage of cells cultured on Myogel were in the G1 and S phase of the cell cycle, indicating an increase in cell division speed by gelatin and, in the next degree, by Myogel. Therefore, Myogel can be used as a suitable substrate to increase the proliferative and migratory potential of MSCs, which are an important factor in tissue engineering.

Heavy metals are considered as one of the important factors threatening water quality in many areas, so they have attracted the attention of many researchers. In this research, the temporal variations of arsenic removal from aqueous solution were investigated using a photocatalytic-adsorbent composite TiO2-Fe2O3 for 360 minutes. Then the capability of linear and nonlinear models of Pseudo-first-order, Pseudo-second-order, Elovich, and power was evaluated in describing the kinetic process.

To determine the kinetics of arsenic adsorption from aqueous solution by TiO2-Fe2O3 composite, batch adsorption experiments were performed at pH 7, initial concentration of 40 mg/L, and adsorbent dose of 1 g/L. After linear and nonlinear fitting of the kinetic models on the adsorption data and finding the constants of each model, the adsorption amount was calculated at different times and compared with the values measured in the laboratory.

The results showed that the amount of adsorption increased with increasing time, and the concentration of arsenic reached equilibrium in 25 minutes. Considering the values of error functions in linear fitting, it was observed that the Pseudo-second-order equation with the lowest errors and the highest coefficient of determination (99.92%) was better agreed to the laboratory data. After this model, the Pseudo-first-order equation performed better, and the weakest simulation was for the Elovich model. In nonlinear analysis, the coefficients of determination of all models were high and very close to each other, so according to the values of error functions, the Elovich model had the lowest error value, which indicates the best fit on the kinetic data. Afterward, power, Pseudo-second order, and Pseudo-first order models had the best fit on the kinetic absorption data, respectively.

Comparison of models up to 360 minutes using the coefficient of determination and error functions (R-squared, root-mean-square error, sum of squares error, sum of absolute errors, absolute relative error, HYBRID, Marquardt’s percentage standard deviation), showed that the use of linear shape can lead to a completely different result and interpretation than the nonlinear shape of the model. So that based on linear methods, Pseudo -second-order model and based on nonlinear methods, the Elovich model had the best fit on kinetic data. Nonlinear fits of kinetic models were also superior to linear forms. In general, the results showed that TiO2-Fe2O3 composite has a high potential for arsenic removal from an aqueous solution.

In the last three decades, drilling a large number of authorized and unauthorized wells has reduced the groundwater level in many aquifers of Iran. In order to improve these conditions, the utilization of groundwater resources should be controlled by considering the appropriate capture zones between wells and qanats. Therefore, a capture zone is considered for each well in operation. In this study, using empirical relationships (Zishard, Comfort, and DuPuit), calculated fixed radius method, and hydraulic equations, computer computational models were presented and the capture zone of ​​4 wells with three flows of 8, 11, and 16 L/s was investigated and calculated in Kavar county (Fars Province). The capture zones calculated by the DuPuit relationship for wells 1 to 4 were 6.16, 5.10, 7.14, and 5.01 m, respectively, which were very small and far from reality. The results showed that Zishard, Comfort, and CFR methods were superior to the DuPuit relationship. Factors affecting the well capture zone were also examined. Since well discharge rate, hydraulic conductivity, pumping time, and transmissivity are directly related to capture zone, with increasing these factors, capture zone also increased. However, unlike the previous factors, the storage coefficient has an inverse relationship with the capture zone and with increasing the amount of storage coefficient, the capture zone decreased. In general, according to the obtained results, if there are reliable parameters for the well location, this computer model can be used as a useful tool to determine the capture zone.

The direct approach of cardiac tissue engineering is to mimic the natural tissue of heart, considering the significant role of scaffolding and mechanical simulation. 

To achieve this purpose, a composite Polycaprolactone (PCL)/Gelatin electrospun scaffold with a ratio of 70:30 and with the most similarities to the cardiac extracellular matrix was fabricated with aligned nanofibers. The scaffold was evaluated using scanning electron microscopy (SEM), mechanical strength analysis, and contact angle test. To simulate the cardiac contraction, a developed Mechanical Loading Device (Bioreactor) was designed to apply a mechanical load with a specific frequency and tensile rate values in the direction of aligned nanofibers due to simulating natural cardiac tissue.

Based on our results from the contact angle and mechanical strength tests, we concluded that our designed scaffold has appropriate adhesion and strength to use as cardiac scaffold and is suitable for imposing the frequency of 1Hz and 10% strain. The Bioreactor also worked properly in producing the required frequency, tensile rate and temperature. 

Since an essential difference between cardiomyocytes and other cells is their contraction, manufacturing a biomimetic bioreactor to simulate the normal cardiac contraction of cardiomyocytes and their required temperature to be survived in-vitro could be a promising approach in cardiac tissue engineering.

Skeletal muscles account for about 40% of the total body weight. Every year, hundreds of people lose at least part of their muscle tissue due to illness, war, and accidents. This can lead to disruption of activities such as breathing, movement, and social life. To this end, various therapeutic strategies such as medication therapy, cell therapy and tissue transplantation have been used or studied in muscle regeneration. However, there is no effective and well-defined clinical approach for treatment of muscle injuries and the severity of muscle injuries increase with age in most cases. Therefore, investigation for finding new and effective clinical approach for muscle regeneration is one of the most important issues in basic and clinical researches. Tissue engineering is considered as one of the promising and newest approach for skeletal muscle tissue regeneration and provides an appropriate model for personalized medicine and basic researches that can be used in personalized medicine and basic research. Besides biomaterials and cells, inducing factors are another element of tissue engineering. These factors influence epigenetic mechanisms and signaling pathway, thereby inducing proliferation, differentiation, and migration of cells used in muscle tissue engineering, and accelerates muscle formation in vitro. Recently, small molecules have been used as alternatives to growth factors or along with other inducing factors in muscle tissue engineering. Since they do not induce an immune reaction, penetrate easily to the cells and have a specific molecular target, therefore they have attracted much attention as the cost-effective inducing factors in tissue engineering.

 Taken together, the effective small molecules in muscle tissue engineering can be used with different biomaterial conditions (e.g. hydrogel, decellularized tissue, and synthetic scaffolds) in both in vivo and in vitro, resulting to production of cost effective and highly efficient engineered muscle tissues that help to achieve therapeutical goals of muscle tissue engineering. Herein, we describe tissue engineering and review the small molecules used in skeletal muscle tissue engineering.

Cardiac tissue engineering is a promising approach for treating cardiac diseases. Since electro-conductivity is an important parameter for cardiac function, here we attempted to produce a conductive scaffold by combining Polypyrrole (as a conductive polymer) and Cardiogel (decellularized heart-derived hydrogel).

The fresh sheep heart was purchased from a slaughterhouse and decellularized using SDS. Then it was digested using pepsin and cardiogel (CG) was prepared. The specific percentages of polypyrrole combined with CG and combined hydrogel were prepared. Then, the combined hydrogel was freeze-dried and the electro-conductive scaffold a CG-Ppy was prepared. Then, cardiac cells were cultured on CG-Ppy scaffold and their viability was assessed using MTS and Live/Dead staining.

Hematoxylin and eosin (H&E), Alcian Blue and Massonchr('39')s trichrome staining and examination of collagen and DNA showed that all heart cells were removed through decellularization, and only heart extracellular matrix was preserved. Evaluation of the gelation process showed that the combination of CG with 2.5% Ppy was the most suitable combination for the production of CG-Ppy combined hydrogel. MTS and Live/Dead staining showed that CG-Ppy scaffold didn’t have any toxicity for cardiac cells, and more than 90% of cultured cardiac cells were viable after one week.

The electro-conductive combined scaffold CG-Ppy is an appropriate model for cardiac tissue engineering and it supports cardiac cells viability.

The Sogadian civilization was on the Silk Road route and was one of the most significant areas of the Silk Road. This geographical location resulted in significant cultural intertwining in the art and culture of the area. The influence of Indian, East Asian and Iranian culture on art are visible. But in the meantime, the influence of Sassanian from Iran may be stronger as the Sogadians received the most influence from the Sassanian in their art. But in this impression, they merely confined themselves to the representation of the Visual Elements of Sasanian art and did not reflect the spirit of royal art in their works. This is especially evident in the Sogadian murals.Research question: What are the reasons for the unique representation of the Visual Elements of Sasanian art and not to reflect the spirit of royal in Sogadian art murals?

Identifying the reasonsfor Sogdian selective influence on some specific aspects of Sassanid art, is the main objective of the present study.

This research is a qualitative one and it is conducted in historical methods as well as the descriptive-analytical study and the required data was collected through a library method.

Sogadian society provided the opportunity for growth for all individuals within the context of the social and political structure of developed urbanization. Due to having such a structure, the money made by being located on the Silk Road route provided considerable prosperity to the people of the area and besides the king, other rich people were formed in the hearts of the population. The same story flourished with epic, mythical, everyday themes, and in Sogadian murals depicting stories that all Sogadian people could be heroes, rather than the central persona and the king’s display of absolute power.

 This research, design and fabrication of a composite scaffold for growth, proliferation and differentiation of Cardiac Progenitor Cells (CPCs) has been considered.

 Polycaprolactone / Gelatin composite scaffolds with a ratio of 70:30 and with the most similarities to the cardiac extracellular matrix was fabricated with aligned nanofibers. Using scanning electron microscopy (SEM), mechanical strength analysisand also contact angel test, the scaffold was investigated due to have the most necessary characteristics to be proportional for cardiac scaffold. Finally, By Real time-PCR test, the expression of the specific genes related to the Cardiac Progenitor Cells differentiation (MYH-6, TTN and CX-43) has been analyzed.

 Based on our results from contact angle test and mechanical strength experiments, we concluded that our designed scaffold is suitable for the culture of Cardiac Progenitor Cells on it. The Real time-PCR analysis also showed the good expression of genes associated with contraction.

 What makes the cardiomyocytes different from other cells is their contraction related to specific cardiac genes being responsible for beating synchronization. The results of this study showed that aligned Polycaprolactone / Gelatin composite scaffold has the appropriate potential for induction of cardiac progenitor cells differentiation and application in heart tissue engineering.

Today, vascular diseases such as atherosclerosis are one of the leading causes of death in the world and the prevalence of it in older societies is rising. The current treatments for repair of cardiovascular function include organ transplantation, surgical reconstruction, mechanical or artificial devices, or the use of metabolic products. Although these methods are commonly used, they did not grow significantly due to the shortage of donors and transmission of infection complications, rejection tissue by the patient's body. Currently, many researches are underway in the field of tissue and medical engineering for the development of new artificial vessels for small diameter vessels. In general, it can be classified as a source of biomaterials for natural and synthetic (biodegradable and non-degradable) broad spectrum of chemical and mechanical properties. The main purpose of tissue engineering is the design of alternative materials in vitro condition using live cells in order to restore the physiological function of the patient's tissue, which is similar to the natural tissue lost. In fact, tissue engineering as an interdisciplinary approach involves incorporating the principles of engineering, cellular and molecular biology, and clinical medicine. The tissue engineering structures consist of three major components: cells, materials, and growth factors. In this article, a review of the biomaterials, fabrication of scaffold, cells, as well as clinical applications in vascular tissue engineering are presented herein.