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ABSTRACTS
Healing of the wound of burned skin remains a major interest of public health importance. Previous reports have confirmed the potential of bone marrow stem cells (BMSCs) in keratinization and vascularization of full thickness skin wounds. In this study, mesenchymal stem cells were isolated from rat adipose tissues and characterized by flowcytometry. Staining methods were used to evaluate their differentiation ability. A collagen-chitosan based scaffold was prepared by freeze drying and cross-linked by a carbodiimide based crosslinker. The cells were cultured on the same scaffold with a little modification and implanted on burned skin in 10 Wistar rats.The differentiation capability of the isolated stem cells, and also, the wound healing potential of this construct were assessed in vivo. The results of immunocytochemistry and PCR experiments confirmed the capability of adipose-derived stem cells (ASCs) in differentiation to the keratinocytes under the treatment of keratinocyte growth factor. The isolated ASCs were seeded on the scaffolds and implanted in the wound beds. The scaffolds without cells were considered as the controls and implanted on the other side of the rat. Histopathological examination confirmed formation of the new tissue, dermis and epidermis after 14 days on the site of implantation of the scaffold-cell constructs. These results indicated the capacity of ASCs for in vivo differentiation to keratinocytes, and also, their ability to promote wound healing.
Cartilage Tissue Engineering, Nanofibers and Stem Cells Masoud Soleimani1* 1 Department of Hematology, Faculty of Medical Science, Tarbiat Modares University, Tehran, Iran *Corresponding author: Massoud Soleimani, PhD, Department of Hematology, Faculty of Medical Science, Tarbiat Modares University, Al-Ahmad Expressway, Tehran PO Box 14115-111, Iran. Tel: +98 21 8288 4508; Fax: +98 21 2235 1460; E-mail:
[email protected] Application of biomaterials in combination with stem cells is a novel tissue engineering approach to regenerate cartilage. The objective of this study was to investigate the potential of poly(vinyl alcohol)/polycaprolactone (PVA/PCL) nanofiber scaffolds seeded with rabbit bone marrow mesenchymal stem cell (BM-MSC) for cartilage tissue engineering in vitro and in vivo. We tested the biocompatibility and mechanical properties of nanofibrous scaffolds using scanning electron microscopy, MTT assay, and tensile measurements. The capacity of MSC for chondrogenic differentiation on scaffolds was examined using reverse transcription polymerase chain reaction and immunostaining. For in vivo assessments, PVA/PCL nanofiber scaffolds with or without MSC were implanted into rabbit full-thickness cartilage defects. To evaluate cartilage regeneration, semi-quantitative grading and histological analysis were performed. Our results showed that PVA/PCL scaffolds supported the proliferation and chondrogenic differentiation of MSC in vitro. Moreover, the animals treated with cell-seeded PVA/PCL scaffolds showed improved healing of defects compared with untreated control and those which received cell-free scaffolds. Our findings suggest that PVA/PCL scaffolds incorporated with MSC can serve as a suitable graft for articular cartilage reconstruction.
The Effects of Platelet Derived Growth Factor on Morphology of Young Chondrocytes in an In Vitro Model of Osteoarthritis Jafar Soleimani Rad*, Leila Roshangar, Azadeh Montaseri, Mehdi Shakibaei Tissue Engineering Research Group, Department of Anatomical Sciences, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran *Corresponding author: Jafar Soleimani Rad, PhD, Tissue Engineering Research Group, Department of Anatomical Sciences, Faculty of Medicine, Tabriz University of Medical Sciences, Golgasht St, Tabriz, Iran. Tel: +98 411 334 2086; Fax: +98 411 334 2086; E-mail:
[email protected] Osteoarthritis is mainly associated with changes in the articular cartilage, which occur following extracellular matrix degradation and reduction of chondrocyte population. The latter is primarily due to apoptosis. The aim of the present study was to investigate the effects of platelet derived growth factor (PDGF), as a potent mitogenic factor for all cells of mesenchymal origin, on morphology of young chondrocytes subjected to interleukin-1 beta (IL-1β). IL-1β is a proinflammatory cytokine used for in vitro simulation of osteoarthritic changes. Chondrocytes were isolated by pronase and collagenase II treatment of the tissue obtained from the articular cartilage. Chondrocytes were divided into three groups after the second passage. The 1st group was not treated with IL-1β or PDGF and considered as the control group. The 2nd group was treated with 10 ng/mL IL-1β to simulate the cartilage degeneration process. The 3rd group was treated with 10 ng/mL PDGF in addition to IL-1β. On the second day of the study, the cells were harvested for electron microscopic studies, which revealed that in the control group, chondrocytes were flat and contained large and elongated euchromatic nuclei. In the second group, the chondrocytes were round and shrunken, contained heterochromatic nuclei and almost showed the characteristics of proapoptotic cells. In the 3rd group, the morphologies of the cells were similar to those in the control group. According to these results, it is
Artif Organs, Vol. 37, No. 7, 2013
concluded that addition of PDGF to the culture medium prevents the morphological changes induced by IL-1β.
An Engineering Technique for Improvement of the Patency Rate of Bypass Grafts Atefeh Solouk1*, Hamid Mirzadeh1,2, Alexander M. Seifalian3,4 1 Department of Biomedical Engineering, Amirkabir University of Technology, Tehran, Iran; 2Departments of Polymer Engineering and Biomedical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Tehran, Iran; 3Center for Nanotechnology & Regenerative Medicine, UCL Division of Surgical & Interventional Sciences, University College London, UK; 4Royal Free Hospital Hampstead NHS Trust, London, UK *Corresponding author: Atefeh Solouk, PhD, Department of Biomedical Engineering, Amirkabir University of Technology (Tehran Polytechnic) 424 Hafez Ave, Tehran 15875-4413, Iran. Tel: +98 21 6454 2359; Fax: +98 21 6646 8186; E-mail:
[email protected] Endothelization of cardiovascular implants will decrease the risk of thrombosis and intimal hyperplasia. We have developed and patented a novel nanocomposite based on polyhedral oligomeric silsesquioxane (POSS) nanoparticle and poly(carbonate urea)urethane (PCU) polymer for biomedical applications including vascular grafting.The polymer has undergone in vitro and three-year large animal studies and is undergoing CE Marking. To enhance the in situ endothelization of graft, we applied various techniques of which plasma surface modification proved to be effective. Therefore; we studied the effects of oxygen plasma treatment on the hemocompatibility of POSS-PCU. POSS-PCU film was fabricated and treated with 60 W of oxygen plasma for 30 and 120 s. The untreated film was used as the control. The samples were contacted with whole blood, maintained at 37°C for 60 min and the absorbance of the supernatant measured at 540 nm in order to calculate the hemolysis ratio. On the other hand, the films were contacted with platelet-rich plasma (PRP) at 37°C for 1 h and in order to measure the platelet adhesion, the number of non-adherent platelets was determined. For evaluation of cellular adhesion, human umbilical vein endothelial cells were cultured on both treated and untreated surfaces. The results showed that treatment of POSS-PCU significantly reduces the hemolysis ratio and platelet adhesion and increases the number of adherent cultured cells. These findings suggest that plasma treatment of POSS-PCU could be an attractive method to improve hemocompatibility and endothelization of a graft and would lead to a higher patency rate of small-diameter vascular grafts.
Human Endometrial Stem Cell Differentiation into Urothelial Cells on the 3D Nanofibrous Silk-Collagen Scaffold Javad Verdi1,2*, Shiva Sharif3, Alexander M. Seifalian4, Seyed Abdolreza Mortazavi-Tabatabaei1, Alireza Shoae-Hassani1,2, Ali Samadikuchaksaraei5,6, Reza Saber7 1 Department of Applied Cell Sciences, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran; 2Department of Stem Cell and Tissue Engineering, Research Center for Science and Technology in Medicine (RCSTiM), Tehran University of Medical Sciences, Tehran, Iran; 3Department of Tissue Engineering, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran; 4UCL Centre for Nanotechnology and Regenerative Medicine, University College London, UK; 5Department of Medical Biotechnology, Faculty of Allied Medicine, Iran University of Medical Sciences, Tehran, Iran; 6 Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran; 7Department of Nanotechnology, Research Center for Science and Technology in Medicine (RCSTiM), Tehran University of Medical Sciences, Tehran, Iran *Corresponding author: Javad Verdi, PharmD, PhD, Department of Applied Cell Sciences, School of Advanced Technologies in Medicine,Tehran University of Medical Sciences, Italia St., Tehran, Iran. Tel: +98 21 8899 1118; Fax: +98 21 8899 1117; E-mail:
[email protected] A number of conditions ranging from congenital abnormalities to cancer and bladder dysfunction need urinary bladder reconstruction, which faces the major challenge of replacement of urinary epithelium. The urothelial cells are resistant to the specific microenvironment produced as the result of contact with urine. Therefore, in ideal conditions, urinary epithelium substitution should be performed using urothelial cells. This study aimed to examine the potential of human endometrial stem cells (EnSCs) to differentiate into urinary bladder epithelial cells (urothelium) on nanofibrous silk-collagen scaffolds, which could be considered as a tissue-engineered substitute of urinary bladder wall. After passage 4, EnSCs were treated by keratinocyte growth factor (KGF) and epidermal growth factor (EGF) and seeded on electrospun collagen V, silk and silk-collagen nanofibres. Later we examined expression of urothelium-specific genes and proteins (uroplakin-Ia, uroplakin-Ib, uroplakinII, uroplakin-III and cytokeratin 20) by immunocytochemistry, RT–PCR and western blotting.Also, scanning electron microscopy (SEM) and histology were used to examine cell-matrix interactions. Results show that DMEM/F12 supplemented with KGF and EGF induced EnSCs to express urothelial
ABSTRACTS cell-specific genes and proteins. On the other hand, cellular proliferation was enhanced by either collagen, silk or silk-collagen scaffolds. Differentiation of EnSCs into urothelial cells was increased by 3D nanofibrous silk-collagen scaffolds. It could be concluded that human EnSC is a suitable cell source for urinary epithelial reconstruction, especially as an autologous cell source in women.
Oral Presentations Bioprinting of Sodium Alginate Hydrogel into Vessel-Like Geometries Using a Novel Microdispenser System Ali Abdollahi1*, Nabiollah Abolfathi1, Fatemeh Navaee1 1 Department of Biomedical Engineering, Amirkabir University of Technology, Tehran, Iran *Corresponding author: Ali Abdollahi, BSc, Department of Biomedical Engineering, Amirkabir University of Technology, 424 Hafez Ave, Tehran 1591634311, Iran. Tel: +98 21 7762 3817; Fax: +98 21 6641 3969; E-mail:
[email protected] Scaffold-based tissue engineering is the conventional technique used for many years. However, this technique encounters the major limitation of random fabrication, which has lead to development of bioprinting to address this issue. This method utilizes a computer-controlled 3D printer to properly position the biological layers in the structure of the construct. In this study, a tube of sodium alginate hydrogel was fabricated for tissue engineering applications. For this purpose, a microdispenser set developed by our team has been used for running the bioprinting system. A 2% wt gelatin was dissolved into 100 mM of CaCl2.2H2O and 0.9 % wt of NaCl solution to make the substrate used as the Ca2+ reservoir for the gelation. Alginate solution (3% wt) was loaded in the microdispenser to print on the gelatin substrate through a nozzle with the inner diameter of 0.0075 in (∼200 μm). The speed of the microdispenser tip and its route of movement were controlled independently by a computer program and resulted in a circular path needed for constructing a tube-shaped scaffold. The target pattern of the 3D alginate was a tube with an inner diameter of 2 mm and a wall thickness of 200 μm. It should be emphasized that various target patterns can be fabricated using different nozzle diameters and speeds of movements. The minimum inner diameter of nozzles that can be used is 0.002 in (∼50 μm). The potential of this setup for printing of this particular hydrogel was confirmed through multiple experiments conducted under a real-time control.
Tissue Engineering Applications of Bioactive SiO2-CaO-P2O5-MgO-(ZnO) Glasses Fatemeh Baghbani1, Fathollah Moztarzadeh1, Leila Hajibaki2, Nader Nezafati1,3, Masoud Mozafari1,4* 1 Biomaterials Group, Faculty of Biomedical Engineering (Center of Excellence), Amirkabir University of Technology, Tehran, Iran; 2Department of Medical Biotechnology, Faculty of Allied Medicine, Iran University of Medical Sciences, Tehran, Iran; 3Department of Nanotechnology and Advanced Materials, Materials and Energy Research Center, Karaj, Iran; 4 Helmerich Advanced Technology Research Center, School of Material Science and Engineering, Oklahoma State University, Tulsa, OK, USA *Corresponding author: Masoud Mozafari, PhD, Helmerich Advanced Technology Research Center, School of Material Science and Engineering, Oklahoma State University, 526 N Elgin Ave, Tulsa, OK 74106, USA. Tel: +1 918 594 8634; Fax: +1 270 897 1179; E-mail:
[email protected] Bioglasses have been shown to be highly bioactive and resorbable. These properties fit with the tissue engineering applications. Recent advances in synthesis of bioactive glasses doped with trace elements, such as Mg and Zn, have opened new possibilities for improvement of biological properties of these materials, which are important to be studied. In this study, using the SiO2-CaO-P2O5-MgO-ZnO systems, bioactive glasses have been synthesized by sol-gel technique and were characterized. To study the formation of apatite layer after incorporation of Zn into the glass matrix, X-ray diffraction, Fourier transform infrared spectroscopy and scanning electron microscopy were performed. On the other hand, the antibacterial activity of Zn containing glass against Pseudomonas aeruginosa has been measured by halo zone test. The surface reactivity in a simulated body fluid indicated that the rate of apatite formation was slower in the glass, which contained higher amounts of Zn. The results showed that CaO-SiO2-P2O5-MgO bioactive glass had a higher bioactivity compared to the glass containing Zn. It has been demonstrated that the presence of Zn in the glass composition improved the chemical durability and antibacterial activity, and slowed down the rate of formation of the apatite layer and decreased the crystalline size of the apatite particles. The Zn containing glasses exhibited an excellent antibacterial activity against P. aeruginosa, which demonstrated their potential to prevent and treat infection at the site of implantation. The ion release kinetics and their effects could provide the possibility of discovering specific properties, which will advance the field of tissue engineering.
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Effectiveness of Human Amniotic Membrane as a Biological Dressing in Pressure Sore Mehdi Dehghani1, Negar Azarpira2*, Hamid Mosayebbi1, Vahid M Karimi1 1 Department of Hematology and Oncology, Hematology Transplant Research Center, Shiraz University of Medical Sciences, Shiraz, Iran; 2Transplant Research Center, Shiraz University of Medical Sciences, Shiraz, Iran *Corresponding author: Negar Azarpira, MD, Transplant Research Center, Namazi Hospital, Shiraz University of Medical Sciences, Shiraz, Iran. Tel: +98 711 6474 331; Fax: +98 711 6474 331; E-mail:
[email protected] Pressure ulcer is a serious health problem in people with mobility disorders. The non-healing wounds and pressure sores cause extensive damage to the skin leading to infection and loss of body fluids. The aim of this study is to evaluate the effectiveness of amniotic membranes (AMs) in healing of bed sores. AMs obtained under sterile condition after elective caesarean delivery were used as biological dressings on 12 patients with bedsores. The wounds were cleaned with sterile normal saline followed by removal of the superficial debris, by washing with a mild povidone-iodine soap solution. The controls were treated locally with dilantin and cases were treated by aseptic application of amnion on the wounds. All patients were male with an age range from 30 to 75 years and total surface areas of 3.2 cm2 to 54 cm2. The bedsores ranged from second degree to deep third degree. The dressings were changed every 2–3 days. The nutritional status of patients was good. The underlying disease was multiple trauma in 4 cases, malignancy in 5 cases, multiple sclerosis in one and 2 others were cord injury and diabetes. The duration of complete healing was from 16 to 30 days. The early sign of healing was a decrease in wound discharge in the first 2-3 days and appearance of granulation tissue in 12–14 days after dressing. No adverse effect such as erythema or infection was reported. Human AM is an efficient biological dressing and easy to use in the treatment of bedsores without any major complication.
Fabrication of Antibacterial Wound Dressing with Silver Nanoparticle Coating: Assessment of Coating Parameters Izadyar Ebrahimi1*, Narges Bahrami2, Saeid Nouri Khorasani2 1 Department of Textile Engineering, Isfahan University of Technology, Isfahan, Iran; 2Department of Chemical Engineering, Isfahan University of Technology, Isfahan, Iran *Corresponding author: Izadyar Ebrahimi, MSc, Department of Textile Engineering, Isfahan University of Technology, Isfahan, 84156-83511, Iran. Tel: +98 919 729 4145; Fax: +98 21 7770 5725; E-mail:
[email protected] This work aimed to study the parameters for coating of nylon 6 fibers with silver nanoparticles for production of antibacterial wound dressing.The coating condition was optimized by assessment of the impact of lipid stabilizer in the control of particle size. Also, various coating methods, including pad-dry-cure and in situ composition of silver nanoparticle on fiber, were evaluated to achieve maximum washing fastness. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used for characterization of the synthesized particles including measurement of particle size. Thermal gravity analysis (TGA) was used for the assessment of loading of silver nanoparticles and washing fastness was used to determine the fastness properties of these nanoparticles.The results of SEM and XRD studies showed that the use of lipid stabilizer has allowed surface loading of the fiber with smaller-sized silver nanoparticles. TGA findings indicated that in situ composition allowed loading of a higher amount of particles on the surface of the fiber. Finally, the examination of washing fastness revealed that use of lipid stabilizer could control the release rate of the nanoparticles.
Mechanobiological Study of Layered Double Hydroxide/HA Composite Scaffolds for Bone Tissue Engineering Applications Fateme Fayyazbakhsh1,2*, Morteza Mehrjou3,4, Mohamadali Shokrgozar3, Abbasali Keshtkar2, Mehran Solati-Hashjin1,5 1 Nanobiomaterials Lab (NBML), Faculty of Biomedical Engineering, Amirkabir University of Technology, Tehran, Iran; 2Endocrinology and Metabolism Research Institute, Tehran University of Medical Science, Tehran, Iran; 3National Cell Bank of Iran, Pasteur Institute, Tehran, Iran; 4 School of Metallurgy and Material Science, Iran University of Science and Technology; 5Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur, Malaysia *Corresponding author: Fateme Fayyazbakhsh, MSc, Nanobiomaterials Laboratory, Faculty of Biomedical Engineering, Amirkabir University of Technology, No.424, Hafez Ave.Tehran 1591634311, Iran.Tel: +98 21 8822 0072; Fax: +98 21 6646 8186; E-mail:
[email protected] In this work, pure layered double hydroxide (LDH), and layered double hydroxides/hydroxyapatite nanocomposite (LDH/HA = 75/25) powders were synthesized via a co-precipitation method. X-ray diffraction, Fourier transform
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