Heydar Khadivi Ayask; Nasrin Sasani; Halimeh Hassanzadeh; Masoud Golestanipour; Ahmad Moloodi; Vahide Sadat Ebrahimi; Maryam M. Matin
Abstract
Bone graft substitutes are used in bone tissue engineering, orthopedics, and dentistry to help bone repair. The sterility and pyrogenicity of the bone grafts before clinical use are considered part of the regulatory requirements, however sterilization of biomaterials is challenging due to the physicochemical ...
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Bone graft substitutes are used in bone tissue engineering, orthopedics, and dentistry to help bone repair. The sterility and pyrogenicity of the bone grafts before clinical use are considered part of the regulatory requirements, however sterilization of biomaterials is challenging due to the physicochemical changes resulting from the localized increase in gamma dose during irradiation. The effects of gamma radiation dose on the biological behavior of synthetic bone grafts have not been extensively investigated. The present study aimed to evaluate the effects of gamma radiation sterilization doses on OsvehOss synthetic bone grafts via chemical, mechanical, and in vitro biological examinations. XRD analysis and compression test were carried out to evaluate the chemical and mechanical changes of synthetic bone grafts induced by the highest gamma radiation dose applied in this study. Human osteosarcoma MG-63 cells were used to assay their osteogenic response while grown on a biphasic bone graft substitute. Cell attachment and proliferation were confirmed via scanning electron microscopy on days 3, 7, and 14 of culture. Alkaline phosphatase (ALP) activity was determined to assess osteogenesis. Alizarin red S (ARS) staining was also used to identify calcium deposition in osteocytes developed after differentiation of MG-63 cells. Our results illustrated that gamma irradiation did not cause dose-dependent changes in chemical and mechanical properties of OsvehOss BCP (Biphasic Calcium Phosphate) bone grafts when the doses increased up to 50 kGy. Furthermore, OsvehOss BCP samples demonstrated high osteoconductivity in all irradiation treatment groups. ALP and ARS analyses also indicated that the application of irradiation doses up to 50 kGy for sterilization of OsvehOss BCP grafts had no significant effects on osteogenesis and calcium deposition in osteoblast cells cultured on grafts. In conclusion, OsvehOss biomaterials can be sterilized safely for biomedical applications.
Sepideh sadat Hosseini; Shadi Mehrzad; Halimeh Hassanzadeh; Hamid Reza Bidkhori; Mahdi Mirahmadi; Madjid Momeni-Moghaddam; Fatemeh Sadeghifar; Moein Farshchian
Abstract
Mesenchymal stem/stromal cells (MSCs) as one of the most important types of adult stem cells secrete a variety of immunomodulatory cytokines. However, their immunomodulatory features strongly depend on the molecular cross-talk between cells and the surrounding microenvironment. Hence, ...
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Mesenchymal stem/stromal cells (MSCs) as one of the most important types of adult stem cells secrete a variety of immunomodulatory cytokines. However, their immunomodulatory features strongly depend on the molecular cross-talk between cells and the surrounding microenvironment. Hence, some strategies were proposed to empower their beneficial effects during cell-therapeutic procedures to avoid confusing results. Licensing the cells with chemical compounds could be considered as one of the most applicable methods for induction of anti-inflammatory status in the cells. Human chorionic gonadotropin (hCG) is a pregnancy related hormone which has been shown to be essential for the establishment of a successful pregnancy. HCG supports the implantation of fetus in the maternal endometrium, due to its immunomodulatory effects. Moreover, the regulatory role of hCG has been previously mentioned in case of some autoimmune-based diseases. In the present study, the capacity of this hormone for induction of different immune-encountered genes expression was examined in primary cultures of human adipose tissue derived mesenchymal stem cells (Ad-MSCs). In this regard, Ad-MSCs were exposed to 10 IU of hCG for 72 hours. Molecular studies via quantitative Real-time PCR (qRT-PCR) experiments were performed to detect gene expression modifications based on the application of SYBR Green as the fluorescent dye and in comparison to the RPLP0 as the housekeeping gene. Results confirmed that hCG significantly upregulated TSG-6, TGF-β1, IL-1β and IL-6 expression levels comparing with the control group, while it downregulates COX-2 expression, and had no statistically significant effects on IL-10 andTDO2. In conclusion, priming Ad-MSCs with hCG may enhance the proliferation and immunoregulatory potential of these cells, although it needs further investigations to reveal involved molecular pathways.
Shadi Mehrzad; Sepideh sadat Hosseini; Madjid Momeni-Moghaddam; Moien Farshchian; Halimeh Hassanzadeh; Mahdi Mirahmadi; Fatemeh Sadeghifar; Hamid Reza Bidkhori
Abstract
Oxidative stress occurs as a result of breaking down the balance between oxidants (e.g., reactive oxygen species (ROS)) and antioxidants in cells. Several studies have shown that there is a close relationship between oxidative stress and inflammation at the sites of injury. Mesenchymal ...
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Oxidative stress occurs as a result of breaking down the balance between oxidants (e.g., reactive oxygen species (ROS)) and antioxidants in cells. Several studies have shown that there is a close relationship between oxidative stress and inflammation at the sites of injury. Mesenchymal stem cells (MSCs) are exposed to endogenous and exogenous oxidants generated during their ex vivo expansion or following in vivo transplantation. α-tocopherol (vitamin E) is a fat-soluble compound known for its anti-oxidant and anti-inflammatory properties. In many studies, the immunomodulatory effects of vitamin E have been observed in vivo. This study aimed to determine whether pretreatment of MSCs with antioxidants like vitamin E, will enhance the anti-inflammatory and immunomodulatory properties of these cells. For this purpose, adipose-derived MSCs (ASCs) were treated with vitamin E (600 μM) for 48 h. Quantitative PCR (qPCR) experiments were performed to evaluate the expression of genes related to inflammation (IL-1β, IL-6, IL-17, IL-10) or immunomodulation (TSG-6, COX-2, TDO2, TGF-β1). Results indicated that vitamin E significantly increased the expression of COX-2, TSG-6, and IL-1β genes at the mRNA level compared with the control group, while it significantly decreased IL-6 and TGF-β expressions. No effect was observed for IL-17, IL-10, and TDO2 genes. These results suggest that in vitro preconditioning of ASCs with vitamin E may allow the cells to improve their anti-inflammatory and immunoregulatory capacities. Vitamin E pretreatment could lead to the improvement of their therapeutic abilities in conditions that are influenced by oxidative stress.
Mahdi Mirahmadi; Asieh Heirani-Tabasi; Halimeh Hassanzadeh; Mandana Pishbin; Hamid Reza Bidkhori; Hojjat Naderi-Meshkin
Abstract
Preconditioning (PC), is an approach to improve therapeutic potential of stem cells against ischemic environment. PC has several advantages over other therapeutic techniques as this results in increase of transplanted stem cells recruitment, retention, survival and subsequently the induction of a more ...
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Preconditioning (PC), is an approach to improve therapeutic potential of stem cells against ischemic environment. PC has several advantages over other therapeutic techniques as this results in increase of transplanted stem cells recruitment, retention, survival and subsequently the induction of a more supportive environment within the damaged tissue via secretion of angiogenic factors. Special attention is needed to recognize new materials, compounds, and conditions to assess the feasibility of PC for being applied in clinics to treat the ischemic diseases.
