محمود اعظمی

Recently, corneal transplantation has been proposed as an effective treatment for irreversible corneal damage which facilitates access to healthy corneas; however, lack of allografts made the treatment subject to many limitations in medicine. In this regard, this study aimed to produce multilayer nanofiber scaffolds for corneal epithelial layer tissue engineering with scaffold compounds of fibroin silk/collage-EGF. The samples were first prepared and identified from the perspective of engineering and biology applications. The results of this study showed that an alternative tissue with a suitable thickness and structure of nanofibers with suitable engineering and biological properties was successfully prepared. In addition, a scaffold was prepared in this research for tissue engineering of the corneal epithelial layer based on silk fibroin and collagen containing aloe vera and epithelial growth factor as the contributing factors and stimuli for better corneal repair. For this purpose, nanofiber three-layer scaffolds were prepared by a combination of electrospinning and electrospray methods characterized by engineering features, such as Scanning Electron Microscope (SEM), to study the degradability for their weight loss, water contact angle, and growth factor. Release as well as static and dynamic mechanical properties were also investigated. Biological characteristics such as cell binding and scaffold differentiation potential were further explored. The results of this study showed the successful preparation of an alternative with a suitable thickness and structure of nanofibers with suitable engineering and biological properties. The obtained results confirmed the production of a proper scaffold with suitable thickness and nanofiber structure. Therefore, the prepared product could potentially be used as a suitable alternative for repairing the damaged corneal epithelial layer.

Adipose-derived stem cells (ADSCs) are the most common stem cell types used for treating a variety of diseases and also improve wound healing in preclinical and clinical trials. Human amniotic membrane (HAM) is one of the biological substitutes with specific potential to be applied in tissue engineering. Piperonylic acid (PA) is a small molecule extracted from black Piper nigrum that can activate signals associated with cell survival, growth, and proliferation.

To evaluate the viability and proliferation of cells, we decellularized HAM and human adipose-derived stem cells (hADSCs) seeded on DHAM inthe presence of piperonylic acid as a small molecule in culture media. Bax and Bcl2 gene expression as apoptosis-related genes was also studied by real-time PCR.

HAM decellularization was confirmed through the H&E and PI staining and DNA content assay. The viability and proliferation of hADSCs seeded onDHAM showed a significant increase in the presence of 75 μM PA. Cell cultivation on DHAM demonstrated significantly decreased Bax gene expression and increased Bcl2 gene expression.

Based on our findings, DHAM as a bio-scaffold and PA can improve the viability and proliferative potential of hADSCs in vitro. PA with growth factor-like properties can be used in various tissues engineeringand in vitro cell cultures.

The purpose of this study was to prepare and compare a hydroxyethyl cellulose/hyaluronic acid (HEC/HA)-based scaffold with and without gelatin for the treatment of second-degree partial-thickness burns. The scaffolds were prepared by freeze-drying method from the aqueous solutions of the mentioned polymers. Microstructural examination by scanning electron microscopy (SEM) indicated the average pore size of 120 and 98 µm for the gelatin-free and gelatin-containing scaffolds, respectively. According to the dynamic rheology measurements (DMA), all the solutions were flowable in which, the loss modulus was higher than the storage one. Moreover, the solutions revealed shear-thinning behaviour at low frequencies, which changed to shear thickening at frequencies higher than 100 s-1. Both loss and storage modulus increased by adding gelatin to the polymer solutions. The scaffolds water uptake was up to 3,000%. The addition of gelatin to the HA/HEC solution increased the polymer network collapse up to 2 hours and led to reducing the scaffolds degradation rate. Cytotoxicity assay in the presence of the scaffolds showed that more than 80 % of the fibroblast cells were viable (compared to the control group), meanwhile, the presence of  gelatin had a positive effect on the metabolic activity of the cells and increased the rate of cell proliferation.  Scratch test results showed the ability of scaffolds to increase the cell migration rate compared to the control sample. The hydroxyethyl cellulose/hyaluronic acid/gelatin scaffold due to the presence of gelatin and improved the cell migration, which indicating the rapid re-epithelialization, reduced wound contraction to   73 % within 24 hours.

Piezoelectric materials are materials that convert electric energy into mechanical energy (acoustic), and vice versa with mechanical pressure on them, electrical energy is produced. The use of lead-free piezoelectric materials in the bone is developing due to its piezoelectric properties. The aim of this study was to investigate the piezoelectric effect of barium titanate. Barium titanate is a bioactive material that is suitable for use in bone tissue engineering. In barium ceramics, non-polar titanate, ferroelectric regions are randomly oriented, and thus the piezoelectric properties are minimal. Therefore, there is a need for polarization to increase piezoelectric properties. For this purpose, this study was carried out by polarization with different voltage and time on two groups of implantation and porous scaffolds. The implants were made with different dimensions, then polished with different voltages and different times, and finally, their piezoelectric properties were investigated by piezoelectric devices. Also, three-dimensional scaffolds with a porosity of 80% were made using foam molding method. The scaffolds were then polarized in the oil at a different voltage and time, and finally, their piezoelectric properties were investigated by piezoelectric force. And then a biological test was performed on them. Finally, it was concluded that both implants and porous scaffolds with polygonation can find the proper properties for use in bone tissue engineering. It was also concluded that the higher the diameter of the implants, the lower the height and the greater the piezoelectric coefficient. Cell test results also confirmed the effect of piezoelectric properties on bone growth.

The main purpose of using scaffolds replacement tissues of the body. The most important part is to choose the type and steel scaffolding so that eventually will replace the damaged tissue. One of the mechanisms proposed to reshape the bone is based on its piezoelectric properties. It seems that the use of piezoelectric materials is an option for use in the body, is a unique privilege. Therefore, the ceramic barium titanate (BaTiO3) having good piezoelectric properties, Curie temperature of about 125˚C and laboratory observations that non-toxic in the body, as a candidate to replace and simulate the performance of bone tissue, has been proposed. In this study, the design and produce of barium titanate piezoelectric ceramic as a bone scaffold with foam casting method and become coated with gelatinous and nanostructured HA composite for bone tissue engineering. Then test its properties by infrared spectroscopy, X-ray diffraction, scanning electron microscopy and mechanical properties were studied. In the end, it was concluded that the barium titanate scaffold produse with foam casting method coated with gelatin nano hydroxyapatite composite structure suitable for use in bone tissue engineering.

This study seeks to find the relationship of social wealth and adherence to religious beliefs with the educational status of students. A kind of correlation method is used in this research, and the survey sample consist of 145 high school students from Sa’in Ghal’e who were chosen on the basis of the stratified random -sampling method, and questionnaires about social wealth and adherence to religious beliefs were distributed among them to fill out. The students’ average mark was used for recognizing the educational status. The collected data were analyzed by Pearson correlation coefficient and regression analysis. The results show that there is a positive and meaningful relationship between adherence to religious beliefs and students’ educational status and between social wealth and students’ educational status. Also, the result of research shows that 37 percent of the changes (variance) of the variable of students’ educational status are explained according to two variables: religious beliefs and social wealth, and 63 percent of the educational status according to the changes of other variables and factors.

Creativity is at the highest level of human cognitive activities. Creativity is potential and ability that thought, writing, behave and practice of man can make, and it involves solving problems. Creative people solve problems before they create or add to its complexity. So, the only way to make these capabilities, individuals can be prepared to deal with changing conditions of life and new opportunities. Study the effect of life Skills training on primary school pupil's creativity increasing. Among primary school pupils in Zanjan province, 86 people were selected using multi-phase random cluster method and simple random method and assigned into two control and experimental groups. Initially Torrance Tests of Creative Thinking in both groups was used. Then, life skills for 20 sessions (40 hours) were taught to the experimental group. After the training sessions, and three months later, both groups were tested by Torrance Creative Thinking. After data gathering, it was analyzed via t-test, variance analysis and Sheffe’s follow-up test statistics. Result (s): The results showed that there was a significant difference between divergent thinking of grade 3 to 4 and also of grade 3 to 5. However, there was not found any significant difference between pupils creative thinking in grade 3 and 5. Accordingly, it can be concluded that through teaching life skills to children, their creativity may enhance.

During past decade, using biomimetic approaches has received much attention by scientists in the field of tissue substitutes preparation. These approaches have been employed for synthesis of bone tissue engineering scaffolds in the case of either materials or synthesis methods. In this study, an apatite phase has been synthesized within gelatin hydrogel in biomimetic condition. The obtained composite hydrogel has changed to a porous scaffold with the application of freeze drying technique in order to be used in bone tissue engineering. To characterize the chemical composition and crystal structure of the synthesized precipitate within hydrogel, FTIR, XRD and TEM analysis were used. Surface morphology and porous structure of the scaffold were studied with SEM. SEM analysis was also used to investigate the quality of cultured osteoblast cells activity. Results approved formation of an apatite phase within gelatin hydrogel in biomimetic condition with crystallite size ranging between 7-10 nm. Porosity percentage of the obtained nanocomposite scaffold was about 82% with pores sizes in the range of 100-350μm. Young’s elastic modulus of the scaffold was comparable with that of the spongy bone. The osteoblast cells cultured on the scaffold showed adhesion, immigration and extracellular matrix excretion on the scaffold internal surfaces. Thus, obtained results indicated the potential ability of the prepared biomimetic bone tissue engineering scaffold to be used in bone tissue repair process.