Cell and Tissue Banking最新文献

Oxygen pressure plays an integral role in regulating various aspects of cellular biology. Cell metabolism, proliferation, morphology, senescence, metastasis, and angiogenesis are some instances that are affected by different tensions of oxygen. Hyperoxia or high oxygen concentration, enforces the production of reactive oxygen species (ROS) that disturbs physiological homeostasis, and consequently, in the absence of antioxidants, cells and tissues are directed to an undesired fate. On the other side, hypoxia or low oxygen concentration, impacts cell metabolism and fate strongly through inducing changes in the expression level of specific genes. Thus, understanding the precise mechanism and the extent of the implication of oxygen tension and ROS in biological events is crucial to maintaining the desired cell and tissue function for application in regenerative medicine strategies. Herein, a comprehensive literature review has been performed to find out the impacts of oxygen tensions on the various behaviors of cells or tissues.

Utilization of acellular scaffolds, extracellular matrix (ECM) without cell content, is growing in tissue engineering, due to their high biocompatibility, bioactivity ad mechanical support. Hence, the purpose of this research was to study the characteristics and biocompatibility of decellularized rat skin scaffolds using the osmotic shock method. First, the skin of male Wistar rats was harvested and cut into 1 × 1 cm² pieces. Then, some of the harvested parts were subjected to the decellularization process by applying osmotic shock. Comparison of control and scaffold samples was conducted in order to assure cell elimination and ECM conservation by means of histological evaluations, quantification of biochemical factors, measurement of DNA amount, and photographing the ultrastructure of the samples by scanning electron microscopy (SEM). In order to evaluate stem cell viability and adhesion to the scaffold, adipose-derived mesenchymal stem cells (AD-MSCs) were seeded on the acellular scaffolds. Subsequently, MTT test and SEM imaging of the scaffolds containing cultured cells were applied. The findings indicated that in the decellularized scaffolds prepared by osmotic shock method, not only the cell content was removed, but also the ECM components and its ultrastructure were preserved. Also, the 99% viability and adhesion of AD-MSCs cultured on the scaffolds indicate the biocompatibility of the decellularized skin scaffold. In conclusion, decellularized rat skin scaffolds are biocompatible and appropriate scaffolds for future investigations of tissue engineering applications.

Background: Improve the quality of donor coordination activities caused by an increased organ donation rate. The aim of this study was to assess the influence of organ donation coordinators' characteristics on rate of donation and family consent rate in Recognition Centers (RCs) and Organ Procurement Units (OPUs) in Iran by analyzing the organ procurement and transplantation data.

Materials and methods: Based on a questionnaire, this retrospective study evaluated the number of confirmed brain deaths, family consent rate, organ recoveries, rate of expired brain death cases before and after family consent in Iran.

Results: According to results, the overall family consent rate in the entire country is equal to 60.63%. The work experience had a significant effect on the number of procured organs (P < 0.004), death rate after family consent (P < 0.04), and eligible donor death before family consent (P < 0.03). The type of unit (RCs or OPUs) had significant difference on death after family consent (P < 0.023), the death before family consent (P < 0.014), the sum of procured organ (P < 0.04).

Conclusion: The consent rate and donor management in the cases of brain death are unacceptable. The coordinators need training to increase their efficiency in terms of family approach and maintenance of brain death. Only by improving the level of family consent and increasing the coordinators' maintenance skills for brain death cases can the amount of organ donation in Iran be doubled to the current amount.

To investigate the characteristics of multilineage-differentiating stress-enduring (Muse) cells labeled with chloromethyl dialkylcarbocyanine (CM-Dil) in culture and in skin wounds of rats. Normal human dermal fibroblasts (NHDFs) were obtained from foreskins and were confirmed by immunocytochemistry with vimentin. Muse cells were derived from NHDFs using long-term trypsinization (LTT), were confirmed using immunocytochemistry with antibodies against stage specific embryonic antigen-3 (SSEA-3) and CD105 and were expanded in suspension cultures. The Muse cells were labeled with CM-Dil and were further evaluated with respect to their biological properties using CCK-8 assays and scratch tests. One hundred µl CM-Dil-labeled Muse cells at a concentration of 5 × 10³/µl were injected subcutaneously at the edges of skin wounds in adult male SD rats. At weeks 1, 3 and 5 after the injection, the distribution of CM-Dil-labeled Muse cells in skin tissues was observed using immunofluorescence microscopy. Muse cells were double-positive for CD105 and SSEA-3. ALP staining of the M-clusters were positive and they displayed orange-red fluorescence after labelling with CM-Dil, which had no adverse effects on their viability, migration or differentiation capacity. One week after the subcutaneous injection of CM-Dil-labeled Muse cells, many cells with orange-red fluorescence were observed at the edges of the skin injuries; those fluorescent spots gradually decreased over time, and only a few Muse cells with fluorescence could be detected by week 5. CM-Dil can be used to label Muse cells without affecting their proliferation, migration or differentiation, and can be used for short-term tracking of Muse cells for the treatment of skin wounds in a rat model.

The Barcelona Tissue Bank was established from the merge of two previous multi-tissue banks. Potential donors are screened by Donor Center staff and multi-tissue retrieval is performed by specialized own teams. Tissue processing and preservation is performed in clean room facilities by specialised personnel. After quality control of both donor and all tissues results, the heart valves and vascular segments are stored until medical request. The aim of this report is to present the cardiovascular tissue activity and retrospectively evaluate the outcomes of the changes performed in last 20 years. Cardiovascular tissue from 4088 donors was received, specifically 3115 hearts and 2095 vascular segments were processed and evaluated. A total of 48% of the aortic valves, 68% of the pulmonary valves and 75% of the vascular segments were suitable for transplant. The main reason for discarding tissue was macroscopic morphology followed by microbiological results, for both valves and arteries. Altogether, 4360 tissues were distributed for transplantation: 2032 (47%) vascular segments, 1545 (35%) pulmonary valves and 781 (18%) aortic valves. The most common indication for aortic valve surgery was the treatment of endocarditis, while for pulmonary valves, it was congenital malformation reconstruction. Vascular segments were mainly used for reconstruction after ischemia. During this period, a number of changes were made with the goal of enhancing tissue quality, safety and efficacy. These improvements were achieved through the use of a new antibiotic cocktail, increasing of donor age criteria and changing the microbiological control strategy.

Reconstruction of right ventricular outflow tract in patients with congenital heart disease in various age groups remains a controversial issue. Currently, a little is known about the fate of secondary and subsequent conduit. The aim of the study was to determine risk factors of conduit failure, evaluate long-term conduit survival, find out which type of conduit should be preferred in case of reoperations. We performed a retrospective analysis of a total of 249 records of valved conduit secondary and subsequent replacement in right ventricular outflow tract in 197 patients. Median follow-up was 5.7 years. The study endpoints were defined as conduit explants; balloon dilatation of the graft (excluding balloon dilatation of left/right pulmonary artery), transcatheter pulmonary valve implantation; heart transplantation or death of the patient. There were total of 21 deaths (11% mortality) among 197 patients during the follow-up, 2 patients underwent heart transplant, in 23 implanted conduits pulmonary angioplasty or/including transcatheter pulmonary valve implantation was afterwards performed due to graft failure, conduit had to be explanted in 46 cases. After 28 years follow-up, freedom from graft failure after 5 years was 77%, 48% after 10 years and 21% after 15 years. Reoperative right ventricular outflow tract reconstruction demonstrates good mid-term and acceptable long-term outcomes regardless of the type of conduit implanted. Worse long-term graft survival of secondary and further conduits is associated with younger age of the recipient at implantation, small size of the conduit, younger age of donor and male donor in case of allograft implantation.

The use of fresh amniotic membrane (AM) is not a viable option, as it has many disadvantages. Preserving the AM reduces the risk of cross-infection and maintains its effectiveness for a long time. In order to maximize the therapeutic effects of the AM, the basic need is to preserve its vitality and the bioactive molecules it contains. However, the effect of preservation procedures on cell viability and growth factors is a still matter of debate. Optimum preservation method is expected to be cost-effective, easily-accessible, and most importantly, to preserve the effectiveness of the tissue for the longest time. However, each preservation technique has its advantages and disadvantages over the other, and each one compromises the vitality and bioactive molecules of the tissue to some extent. Therefore, the best method of preservation is still controversial, and the question of 'how to preserve the AM best?' has not yet been definitively answered.

Bone allografts are clinically used in a variety of surgical procedures, and tissue banks are responsible for harvesting, processing, quality testing, storing, and delivering these materials for transplantation. In tissue banks, the bone is processed for the removal of all organic content, remaining only the tissue structure (scaffold). However, several studies have shown that even after using different processing methods, viable cells, functional proteins, and DNA may still persist in the tissue, which constitute the main causes of graft rejection. Therefore, the objective of this study was to establish techniques and biological parameters for quality validation of allografts. To this end, we propose the use of 3 combined methods such as microscopy, histology, and molecular biology techniques to evaluate the quality of allografts harvested and processed by the Brazilian National Institute of Traumatology and Orthopedics (INTO) tissue bank according to the donation criteria of the Brazilian National Health Surveillance Agency and the Brazilian National Transplant System. Bone fragments from different processing stages showed no viable cells on histology, an intact extracellular matrix on scanning electron microscopy, and gradual reduction in DNA amount. Different techniques were used to demonstrate the quality of allografts produced by the INTO tissue bank and to establish biological parameters for ensuring the safety and quality of these products. Future studies need to be undertaken to assess and validate the efficacy of the decellularization process in larger bone grafts with diverse architectural configurations.

Exosomes, the naturally secreted nanocarriers of cells, have recently been demonstrated to have therapeutic benefits in a variety of disease models where parent cells are not present. However, the use of exosomes in bone defect regeneration has been unusual, and little is documented about the underlying processes. In recent study we produced and characterized exosomes derived human endometrial mesenchymal stem stromal cells and 58S bioactive glass scaffolds; in following, in this research exosome loaded scaffolds synthetized and release of exosome, porosity and bioactivity of them were assessed. More over the effect of scaffolds on repair of critical-size bone defects in rat’s calvaria was evaluated by histological examination and micro computed tomography (µ CT). The findings confirmed that constructed porous scaffolds consistently release exosomes; additionally, in vivo findings including Hematoxilin & Eosin staining, Immunohistochemistry, Masson's trichrome, histomorphometric analysis, and µ CT clarified that our implant has osteogenic properties. We discovered that Exo-treated scaffolds might promote osteogenesis especially compared to pure scaffolds, indicating that produced scaffolds containing exosomes could be a potential replacement in bone tissue engineering.

This study aimed to evaluate the efficacy of cryopreserved amniotic membrane (AM) grafts in chronic wound healing, including the mean percentage of wound closure per one AM application, and to determine whether the healing efficiency differs between AM grafts obtained from different placentas. A retrospective study analyzing inter-placental differences in healing capacity and mean wound closure after the application of 96 AM grafts prepared from nine placentas. Only the placentas from which the AM grafts were applied to patients suffering from long-lasting non-healing wounds successfully healed by AM treatment were included. The data from the rapidly progressing wound-closure phase (p-phase) were analyzed. The mean efficiency for each placenta, expressed as an average of wound area reduction (%) seven days after the AM application (baseline, 100%), was calculated from at least 10 applications. No statistical difference between the nine placentas' efficiency was found in the progressive phase of wound healing. The 7-day average wound reduction in particular placentas varied from 5.70 to 20.99% (median from 1.07 to 17.75) of the baseline. The mean percentage of wound surface reduction of all analyzed defects one week after the application of cryopreserved AM graft was 12.17 ± 20.12% (average ± SD). No significant difference in healing capacity was observed between the nine placentas. The data suggest that if there are intra- and inter-placental differences in AM sheets' healing efficacy, they are overridden by the actual health status of the subject or even the status of its individual wounds.