Accelerating cryoprotectant delivery using vacuum infiltration

Ryan J. Forcier et al
Cryobiology, (September 2023). DOI: 10.1016/j.cryobiol.2023.104558

Summary: The ability to cryopreserve bone marrow within the vertebral body (VB) would offer significant clinical and research benefits. However, cryopreservation of large structures, such as VBs, is challenging due to mass transport limitations that prevent the effective delivery of cryoprotectants into the tissue. To overcome this challenge, we examined the potential of vacuum infiltration, along with carbonation, to increase the penetration of cryoprotectants.

Characterization and Function of Cryopreserved Bone Marrow from Deceased Organ Donors: A Potential Viable Alternative Graft Source

Brian H. Johnstone et al
Transplantation and Cellular Therapy, (November 2022). DOI: 10.1016/j.jtct.2022.11.010

Summary: Despite the readily available graft sources for allogeneic hematopoietic cell transplantation (alloHCT), a significant unmet need remains in the timely provision of suitable unrelated donor grafts. This shortage is related to the rarity of certain HLA alleles in the donor pool, nonclearance of donors owing to infectious disease or general health status, and prolonged graft procurement and processing times. An alternative hematopoietic progenitor cell (HPC) graft source obtained from the vertebral bodies (VBs) of deceased organ donors could alleviate many of the obstacles associated with using grafts from healthy living donors or umbilical cord blood (UCB). Deceased organ donor-derived bone marrow (BM) can be preemptively screened, cryogenically banked for on-demand use, and made available in adequate cell doses for HCT.

Transplantation of Hematopoietic Stem and Progenitor Cells from Cadaveric Organ Donors Leads to Long-Term Multilineage Engraftment in NSG Mice

L. Breyer, H. Wang, D. Gu, B. Johnstone, H. Ma, E. Woods and M. Mapara
American Society of Hematology, (November 2022). DOI: 10.1182/blood-2022-169787,

Summary: Hematopoietic Stem and Progenitor Cells (HSPC) from cadaveric donors (CDs) have been used historically almost exclusively in the context of tolerance induction in combined bone marrow (BM) and solid organ transplantation. To date, no systematic study has addressed their functional long-term engraftment capacities. However, HSPC from banked CDs might be of high importance since they increase the still limited donor pool with on-demand availability as well as allow potential tolerance induction for patients undergoing combined transplantation.

Preservation and Storage of Cells for Therapy: Current Applications and Protocols

Jason P. Acker et al
Cell Engineering and Regeneration, (June 2022). DOI: 10.1007/978-3-319-37076-7_68-1

Summary: In this chapter we consider the particular preservation storage procedures applied to a range of cell types used to produce cell-based medicines. Specifically, it deals with the scientific considerations for preserving each cell type and the kinds of cryopreservation protocols used to successfully preserve these different cell types. The cell types addressed include both those commonly in current use for patient treatment, such as whole blood and hematopoietic stem cells and also examples of new cell-based medicines including tissue progenitor cells (MSCs), (The use of the term Mesenchymal Stem Cell (MSC) has been hotly debated in the literature as it actually applies to several different cell types.

A Large-Scale Bank of Organ Donor Bone Marrow and Matched Mesenchymal Stem Cells for Promoting Immunomodulation and Transplant Tolerance

B.H. Johnstone, F. Messner, G. Brandacher, and E.J. Woods
Frontiers in Immunology, (February 2021). DOI: 10.3389/fimmu.2021.622604

Summary: Induction of immune tolerance for solid organ and vascular composite allografts is the Holy Grail for transplantation medicine. This would obviate the need for life-long immunosuppression which is associated with serious adverse outcomes, such as infections, cancers, and renal failure. Currently the most promising means of tolerance induction is through establishing a mixed chimeric state by transplantation of donor hematopoietic stem cells; however, with the exception of living donor renal transplantation, the mixed chimerism approach has not achieved durable immune tolerance on a large scale in preclinical or clinical trials with other solid organs or vascular composite allotransplants (VCA). Ossium Health has established a bank of cryopreserved bone marrow (BM) to deal with this issue.

Ischemia considerations for the development of an organ and tissue donor derived bone marrow bank

E.J. Woods, A.M. Sherry, J.R. Woods, J.W. Hardin, M. LaFontaine, G. Brandacher, and B.H. Johnstone
Journal of Translational Medicine, (August 2020). DOI: 10.1186/s12967-020-02470-1 

Summary: Deceased organ donors represent an untapped source of therapeutic bone marrow (BM) that can be recovered in 3–5 times the volume of that obtained from living donors, tested for quality, cryopreserved, and banked indefinitely for future on-demand use. A challenge for a future BM banking system will be to manage the prolonged ischemia times that are inevitable when bones procured at geographically-dispersed locations are shipped to distant facilities for processing. In this study, we: (a) quantify, under realistic field conditions, the relationship between ischemia time and the quality of hematopoietic stem and progenitor cells (HSPCs) derived from deceased-donor BM; (b) identify ischemia-time boundaries beyond which HSPC quality is adversely affected; (c) investigate whole-body cooling as a strategy for preserving cell quality; and (d) investigate processing experience as a variable affecting quality.

Identification and characterization of a large source of primary mesenchymal stem cells tightly adhered to bone surfaces of human vertebral body marrow cavities

B.H. Johnstone, H.M. Miller, M.R. Beck, D. Gu, S. Thirumala, M. LaFontaine, G. Brandacher, E.J. Woods
Cytotherapy, (July 2020). DOI: 10.1016/j.jcyt.2020.07.003

Summary: Therapeutic allogeneic mesenchymal stromal cells (MSCs) are currently in clinical trials to evaluate their effectiveness in treating many different indications. Eventual commercialization for broad distribution will require further improvements in manufacturing processes to economically manufacture MSCs at scales sufficient to satisfy projected demands. We have discovered that an abundant population of cells possessing all the hallmarks of MSCs is tightly associated with the vertebral body (VB) bone matrix and only liberated by proteolytic digestion. Here we demonstrate that these vertebral bone-adherent (vBA) MSCs possess all the International Society of Cell and Gene Therapy-defined characteristics (e.g., plastic adherence, surface marker expression and trilineage differentiation) of MSCs, and we have therefore termed them vBA-MSCs. We have established this as a novel and plentiful source of MSCs that will benefit the cell therapy market by overcoming manufacturing and regulatory inefficiencies due to donor-to-donor variability.