Stem cells can be isolated from various human tissues including bone marrow (BM) and adipose tissue (AT). Our study outlines a process to isolate adult stem cells from deceased donors. We have shown that cell counts obtained from deceased donor BM were within established living donor parameters. Evaluation of demographic information exhibited a higher percentage of hematopoietic stem cells (HSC) in males versus females, as well as a higher percentage of HSC in the age bracket of 25 years and under. For the first time, we show that deceased donor femur BM grew cell colonies. Our introduction of new technology for nonenzymatic AT processing significantly increased cell recovery over the traditional enzymatic processing method. Cell counts from the deceased donor AT exceeded living donor parameters. Furthermore, our data illustrated that AT from female donors yielded a much higher number of total nucleated cells (TNC) than males. Together, our data demonstrates that our approach to isolate stem cells from deceased donors could be a routine practice to provide a viable alternative to living donor stem cells. This will offer increased accessibility for patients awaiting stem cell therapies.

Organ transplantation is essential and crucial for saving and enhancing the lives of individuals suffering from end-stage organ failure. Major challenges in the medical field include the shortage of organ donors, high rates of organ rejection, and long wait times. To address the current limitations and shortcomings, cellular therapy approaches have been developed using mesenchymal stem/stromal cells (MSC). MSC have been isolated from various sources, have the ability to differentiate to important cell lineages, have anti-inflammatory and immunomodulatory properties, allow immunosuppressive drug minimization, and induce immune tolerance towards the transplanted organ. Additionally, rapid advances in the fields of tissue engineering and regenerative medicine have emerged that focus on either generating new organs and organ sources or maximizing the availability of existing organs. This review gives an overview of the various properties of MSC that have enabled its use as a cellular therapy for organ preservation and transplant. We also highlight emerging fields of tissue engineering and regenerative medicine along with their multiple sub-disciplines, underlining recent advances, widespread clinical applications, and potential impact on the future of tissue and organ transplantation.

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Objectives. There are four immunoglobulin (IgG) subtypes that have varying complement-activating ability: strong (IgG3 and IgG1) and weak (IgG2 and IgG4). The standard flow cytometric crossmatch (FCM) assay does not distinguish between the various subtypes of the IgG molecule. This study outlines the development and use of a novel cell-based IgG subtype-specific FCM assay that is able to detect the presence of and quantitate the IgG subtypes bound to donor cells. Methods. A six-colour lyophilised reagent was designed that specifically detects the four IgG subtypes, as well as distinguishes between T cells and B cells in the lymphocyte population. To test the efficacy of this reagent, a retrospective evaluation of a group of highly sensitised patients awaiting heart and kidney transplant was carried out, who, because of positive standard FCM results, had been deemed incompatible with numerous prior potential donors. Results. Observations in this study demonstrate that the positive standard FCM results were mainly because of the presence of noncomplement-activating IgG2 or IgG4 antibodies. The results were supported by the absence of C3d-binding donor-specific antibodies (DSA) and a negative complement-dependent cytotoxicity crossmatch (CDC). Conclusion. Preliminary data presented in this study demonstrate the reliability of the novel IgG subtype assay to detect the presence of pretransplant, complement-activating antibodies bound to donor cells. The knowledge gained from the IgG subtype assay and the C3d-binding specificities of DSAs provides improved identification of donor suitability in pretransplant patients, potentially increasing the number of transplants.

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Controlled rate freezing is recognized as a method of choice for the cryopreservation of blood cells. DMSO, the cryoprotectant most commonly used for cryopreservation of cells, is well known to affect cell viability. It is therefore imperative to insure that cells are frozen without any appreciable delay after the addition of DMSO. Addition of cryoprotectant may take between 5–10 minutes per processed cord blood unit. In situations involving large scale processing, such as 5–10 cord blood units simultaneously, delay will occur, which could cause adverse affects on cell viability when controlled rate freezing is utilized This study was designed to compare the effect of controlled with two non-controlled rate freezing methods on cord blood stem cell viability. After adding DMSO to final concentration of 10%, each cord blood unit was split into two 25 ml volumes and enclosed in metal freezing canisters. The UCB units were covered by styrofoam sleeves and then placed directly into either a −80°C or a −140°C mechanical freezer. A corresponding portion of each unit was frozen utilizing a Forma Scientific, model 1010 controlled rate freezer. Approximately 30 days after, matching units were thawed in a 37°C water bath and tested without washing. Total Nucleated Cell count, Total CD34 count, 7AAD viability and colony forming units assay were performed on fresh and cryopreserved/thawed samples. Statistical pair analysis using student-t test was performed to indicate any statistically significant differences between each procedures. (table1) (table2) Results indicate that all three methods produces similar cell viability as measured by total nucleated cell recovery, total CD34 counts, 7AAD viability and colony forming assays. Analysis of fresh and frozen samples did not indicate that controlled rate freezing produces a better quality product after thawing compared to two uncontrolled freezing methods. Controlled rate freezing vs −80oC dump method° N=5 Fresh Sample Controlled Rate Freezing Non controlled Freezing at −80oC TNC (x10^6) 412.4 ±37.06 397.6±15.65 406.7±24.78 Total CD34+ (10^6) 0.23±0.08 0.19±0.08 p<0.05 0.19±0.07 p<0.05 Viability (%) 97.5±1.67 94.8±2.28 p<0.05 93.4±3.51 p<0.05 Total # of Colonies (x10^6) 0.27±0.09 0.21±0.10 p<0.05 0.20±0.08 p<0.05 Controlled rate freezing vs −140oC dump method N=5 Fresh Sample Controlled Rate Freezing Non Controlled −140oC TNC (10^6) 365.4±100.87 372.1±102.18 365.9±104.9 Total CD34+ (x10^6) 0.28±0.08 0.023±0.05 p<0.05 0.23±0.05 p<0.05 Viability (5) 96.0±3.94 96.2±2.28 p<0.05 96.2±1.79 Total # of Colonies (10^6) 0.27±0.13 0.27±0.11 0.24±0.15