Showing 5 results for Tissue Engineering
Sanambar Sadighi , Ahad Khoshzban , Amir Hossein Tavakoli , Ramin Khatib Semnani, Zahra Sobhani , Nayer Dadashpur Majidabad,
Volume 72, Issue 1 (4-2014)
Abstract
Background: Currently, autologous and allogeneic adipose tissues represent a ubiqui-tous source of material for fat reconstructive therapies. However, these approaches are limited, and often accompanied by a 40-60% reduction in graft volume following transplantation, limited proliferative capacity of mature adipocytes for ex vivo expansion, and extensive adipocyte damage encountered when harvested with conventional liposuction techniques. Recently, cell-based approaches utilizing adipogenic progenitor cells for fat tissue engineering have been developed and were reported to promote both short-term in vivo adipogenesis and to repair defect sites. The aim of this study was to isolate stem cells from fat tissue than examine the growth of stem cells by invitro tests.
Methods: For human adipose stem cell isolation (hASC), subcutaneous adipose tissue sites were obtained from female subjects undergoing elective procedures. Tissues were washed 3-4 times in phosphate buffered saline (PBS) and suspended in an equal volume of PBS supplemented with 1% FCS and 0.1% collagenase type I. The tissue was placed in an agitated water bath at 37 1C. The supernatant containing mature adipocytes, was aspirated. Portions of the SVF were suspended in DMEM medium. hASCs were selected based on their ability to adhere to tissue culture plastic and subsequently expanded to 75-90% confluence. Adipose stem cells were isolated and cultured on DMEM. To assess mesenchymal origin of stem cells we used flow-cytomery technique as well as differentiation to osteocyte and chondrocyte lines.
Results: The nature of the mesenchymal cells was confirmed by flow -cytometry tech-niques, based on the expression of CD90, CD105, CD166, and lack of expression of hematopoietic markers of CD34, CD31, and CD45. The successful differentiation of our stem cells to osteocyte, chondrocyte had been showed by specific Alizarin-Red and Toluidine-blue staining of cells.
Conclusion: Although we have not the results of in vivo tests to support in vivo adipo-genesis either alone or in combination with natural or synthetic matrix, the results showed that stem cells isolation from adipose tissue was successful, and we provided an environment for differentiation of stem cells.
Sanambar Sadighi, Amir Hosien Tavaccoli, Nayer Dadash Poor , Kazem Hosieny ,
Volume 72, Issue 6 (9-2014)
Abstract
Background: With the aim of regenerating healthy tissues, different tissue engineering strategies pointed to extracellular matrix (ECM)-based scaffolds in tissue engineering and regenerative medicine and wound healing. It is a multidisciplinary science works to create biocompatible scaffolds with perfect physical parameters, mechanical integrity and high porosity to promote cell growth, migration and angiogenesis. With the increased incidence of obesity, subcutaneous adipose tissue is abundant and readily accessible. Liposuction surgeries yield from 100 mL to 3 L of lipoaspirate tissue.
We present our prepared acellular ECM powders derived from human adipose tissue obtained from lipoaspirate, which contains large amounts of collagen suitable for induction of adipogenesis.
Methods: The study had been carried out from December 2012 to March 2013 in Tissue Bank and Research Center in Imam Khomeini Hospital Tehran, Iran. Fresh human adipose tissue was obtained by liposuction of abdominal fat pad in a private Day Clinic. By using wasted material of liposuction, we obtained 100 to 200 cc fat tissue from each patient. After physical (freeze-thaw-slicing-manual massage) and chemical (enzymatic-detergent-acid digestion) treatment, an acellularized matrix was created from fat tissue. The final material lyophilized and ground to powder. We analyzed ultra structure and biochemical properties of obtained ECM powder by using electron microscopy, immunohistochemistry (IHC) examination and proteomic studies.
Results: After mechanical and chemical process of decellularization, scanning electron micrographs of the samples showed smooth and contiguous collagenous components throughout the scaffold. IHC showed strong positive labeling for collagen IV and no evidence of nuclear material in the specimen.
Separation of protein complex by Blue Native Polyacrylamide gel electrophoresis (BN-PAGE) has proven type I collagen triple helices associate to form banded fibrils. RNA preparation and Gene Expression Analysis (RT-PCR) by using specific primers for laminin, fibronectin, collagen type I and IV, desmin, and actin showed strong staining of our fat tissue scaffold with collagen type I, fibronectin, collagen IV and laminin.
Conclusion: The results show that our decellularization method produced an adipose ECM scaffold rich of collagen fibers, suitable and effective substrate for use in soft tissue engineering and regenerative medicine.
Maryam Ataie , Atefeh Solouk , Fatemeh Bagheri , Ehsan Seyed Jafari,
Volume 75, Issue 4 (7-2017)
Abstract
An increase in the average age of the population and physical activities where the musculoskeletal system is involved as well as large number of people suffering from skeletal injuries which impose high costs on the society. Bone grafting is currently a standard clinical approach to treat or replace lost tissues. Autografts are the most common grafts, but they can lead to complications such as pain, infection, scarring and donor site morbidity. The alternative is allografts, but they also carry the risk of carrying infectious agents or immune rejection. Therefore, surgeons and researchers are looking for new therapeutic methods to improve bone tissue repair. The field of tissue engineering and the use of stem cells as an ideal cell source have emerged as a promising approach in recent years. Three main components in the field of tissue engineering include proper scaffolds, cells and growth factors that their combination leads to formation of tissue-engineered constructs, resulting in tissue repair and regeneration. The use of scaffolds with suitable properties could effectively improve the tissue function or even regenerate the damaged tissue. The main idea of tissue engineering is to design and fabricate an appropriate scaffold which can support cell attachment, proliferation, migration and differentiation to relevant tissue. Scaffold gives the tissue its structural and mechanical properties, for instance flexibility and stiffness that is related with the tissue functions. Biomaterials used to fabricate scaffolds can be categorized into natural or synthetic biodegradable or non-biodegradable materials. Polymers are the most widely used materials in tissue engineering. Growth factors are a group of proteins that cause cell proliferation and differentiation. Two main cell sources are specialized cells of desired tissue and stem cells. However, according to the low proliferation and limited accessibility to the cells of desired tissue, stem cells are better suggestion. Combination of mesenchymal stem cells harvested from bone marrow, adipose tissue and cord blood with proper scaffolds and growth factors could be a useful method in treatment of skeletal injuries. In this review paper, we focus on the application of mesenchymal stem cells in the repair of damaged bone, cartilage, meniscus, ligaments, tendons and spine tissue.
Arash Abdolmaleki, Mohammad-Bagher Ghayour, Saber Zahri, Asadollah Asadi , Morteza Behnam-Rassouli ,
Volume 77, Issue 2 (5-2019)
Abstract
Background: Tissue engineering is a developing multidisciplinary and interdisciplinary field involving the use of bioartificial implants for tissue remodeling with the target for repair and enhancing tissue or organ function. Acellular nerve has been used in experimental models as a peripheral nerve substitute. The purpose of the present study was to evaluate the mechanical and histological characteristics of acellular nerve scaffolds compared to the fresh nerve for application in environmental nerve repair.
Methods: This experimental study was conducted in Ferdowsi University of Mashhad Regeneration Research Laboratory, Mashhad, Iran, from May 2017 to October 2018. In this study for preparing the scaffold. The rats were sacrificed by intraperitoneal anesthesia with 10 % Chloral Hydrate solution. Then sciatic nerve fragments of the rats were removed above the nerve branching site and after cleansing of the tissues were decellularized by Sondell method, briefly nerves were treated with a series of detergent baths consisting of distilled water for 8 h, Triton X-100 for 12 h, and sodium deoxycholate for 24 hours according to the Sondell protocol. All acellularization steps were performed at room temperature. Then decellularized scaffolds were evaluated histologically and mechanically.
Results: The results of tissue evaluations showed that decellularization of scaffolds were done completely, this was demonstrated by hematoxylin and eosin staining and DAPI staining. Also the specialized tissue evaluations by picro-fuchsin staining and evaluation the scaffolds by scanning electron microscopy (SEM) micrographs showed that the collagen and elastin strands are relatively preserved in the extracellular matrix in comparison with control groups. As well as mechanical examination of scaffolds in tensile test showed that extracellular matrix of scaffolds was relatively preserved the main components of tissue compared to control group and scaffolds have good mechanical resistance quality for use in tissue engineering.
Conclusion: The results of the present study showed that decellularized scaffolds that prepared with Sondell decellularization method by preserving the main components of the tissue can be a good platform for investigating cellular behaviors.
Mahnaz Mahmoudi Sohi , Asadollah Asadi , Peyman Brouki Milan , Esmaeil Sharifi, Arash Abdolmaleki,
Volume 79, Issue 4 (7-2021)
Abstract
Background: Wound healing is a complicated process involving the proliferation of the epithelial cells, deposition of granulation tissue as well as recruitment of inflammatory cells. It also is a hot topic of research for trauma, orthopedics and general surgery studies. There are many forms of cells involved in this process. This study aimed to design a tissue-engineered wound dressing consisting of chitosan fibers containing silver ion bioactive nanoparticles for wound healing.
Methods: The present study is an experimental study that was conducted in the research laboratory of the Department of Biology of Mohaghegh Ardabili University from April to November 2019. All experiments of this study have been performed under the ethical guideline of Helsinki and in accordance with the Ethics Committee of the Mohaghegh Ardabili University of Ardabil (Iran). The wound dressing of nanofibers was prepared by the sol-gel method. Cytotoxicity was assessed by MTT assay. Then the antimicrobial properties of nanofibers were determined by the disk diffusion method. SEM and AFM images were obtained from nanofibers. Finally, nanofibers were analyzed by the FTRI method.
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Results: Results of the prepared tissue-engineered wound dressing consisting of chitosan fibers containing silver ion-doped bioactive nanoparticles showed that cytotoxicity was at an appropriate level. The nanofibers prepared with 2% silver nanoparticles produced a 10 mm inhibition zone against Staphylococcus aureus and a 9 mm inhibition zone against Escherichia coli. Therefore, the best percentage of scaffolds in the present study was 2%. Also, results of the SEM micrographs and AFM image analysis of the scaffolds showed that the nanofibers had good roughness and a proper structure for cell seeding and attachments. Besides that, FTIR analysis also showed that the prepared nanofibers had standard bonds.
Conclusion: Chitosan-Silver nanoparticles scaffold have antimicrobial activity on Gram-negative and positive bacteria. The results of the toxicity test also showed that it did not have much toxicity on the cultured cells. Therefore, it can be considered for therapeutic applications, such as wound dressing.
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