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Fisher, B. J.

Publications and source records attributed to Fisher, B. J..

3 recordsLinked to original sources

Functional recovery of vitrified and nanowarmed human-scale pig kidneys

Organ transplantation is critically constrained by the short preservation window for donor organs, limiting allocation and contributing to organ discard and waitlist mortality. Cryogenic organ banking could extend preservation from hours to months or years, but ice formation, thermal stress and cryoprotectant toxicity become increasingly difficult to control as organ size increases. Vitrification and nanowarming have enabled long-term preservation and transplantation of rodent kidneys but have not been demonstrated at the scale of clinically relevant organs. Here we show that vitrification and electromagnetic nanowarming enable long-term cryogenic storage and functional recovery of human-scale porcine kidneys. Kidneys 100-fold larger than previously nanowarmed kidneys were successfully recovered after storage at -150 {degrees}C for up to one year. A new cryoprotectant formulation and multithermic perfusion strategy enabled ice-free vitrification at cooling rates achievable in large kidneys, while controlled cooling with annealing and staged volumetric nanowarming limited thermal stress and enabled rapid rewarming without cracking. Rewarmed kidneys demonstrated vascular, metabolic and excretory function during normothermic perfusion, with limited histological injury, and reperfused homogeneously and produced urine immediately after transplantation. Functional recovery approached static cold storage outcomes across several measures and was similar to that of kidneys exposed to cryoprotectant alone, suggesting minimal additional functional injury from vitrification, cryogenic storage and nanowarming. These findings overcome major scale and storage-duration barriers to organ cryopreservation and establish a path toward organ banking on timescales far beyond those of conventional preservation.

bioengineering↗

Clinical grade cryopreservation unlocks transplant ready human pancreatic and stem cell derived islets for diabetes therapy

Pancreatic islet transplantation can restore endogenous insulin production and offers a potential cure for diabetes, but its clinical impact has been limited by the inability to preserve large numbers of functional islets for timely use. Cryopreservation could provide an on-demand supply, yet conventional methods cause ice formation, cell injury, and loss of insulin secretion. We developed CryoMesh, a vitrification platform that combines a low-toxicity cryoprotectant with a thermally conductive, biocompatible mesh to enable ultra-rapid cooling and rewarming for ice-free cryopreservation. This approach supports long-term, clinical-scale preservation of both human pancreatic and stem cell-derived islets while maintaining viability, architecture, mitochondrial integrity, and glucose-responsive insulin secretion. Human islets preserved for up to one year restored normoglycemia in diabetic mice, with complete recovery of function and no increase in immunogenicity or loss of potency. The combination of high viability, recovery, and functional preservation at clinical scale has not been achieved previously. By decoupling islet isolation and manufacture from transplantation, CryoMesh enables extended quality, potency, and safety testing, cost-effective batch production, and global banking and distribution. These capabilities remove a major barrier to curative cell therapy for diabetes and establish a generalizable strategy for preserving complex multicellular therapeutics. One Sentence SummaryA clinical scale vitrification platform enables long-term banking of human pancreatic and stem cell-derived islets for transplantation.

cell biology↗

Risk stratification of allogeneic stem cell recipients with respect to the potential for development of GVHD via their pre-transplant plasma lipid and metabolic signature

The clinical outcome of allogeneic hematopoietic stem cell transplantation (SCT) is strongly influenced from the complications arising during the post-transplant immune restoration and has been well studied and described. However, the metabolic status of the recipient pre-transplant also has the potential to influence this outcome and has never been studied before and has the potential to enable risk stratification with respect to the development of transplant associated complications such as graft vs. host disease (GVHD). In order to better understand this aspect of transplant related complications we investigated the pre-transplantation metabolic signature to assess the possibility of pre-transplant risk stratification. This pilot study was composed of 14 patients undergoing myeloablative conditioning followed by either HLA matched related, unrelated donor, or autologous stem cell transplantation. Blood samples were taken prior to transplant and the plasma was comprehensively characterized with respect to its lipidome and metabolome via LCMS and GCMS. The results indicated a significantly pro-inflammatory metabolic profile in patients who eventually developed Graft vs. Host Disease (GVHD). The data revealed 5 potential pre-transplant biomarkers (1-monopalmitin, diacylglycerol (DG) 38:5, DG 38:6, 2-aminobutyric acid, and fatty acid (FA) 20:1) that demonstrated high sensitivity and specificity towards predicting post-transplant GVHD development. The predictive model developed demonstrated an estimated predictive accuracy of risk stratification of 100%, with an Area under the Curve of the ROC of 0.995 with 100%. The likelihood ratio of 1-monopalmitin (infinity), DG 38:5 (6.0) and DG 38:6 (6.0) also demonstrated that a patient with a positive test result for these biomarkers pre-transplant will likely have very high odds of developing GVHD post-transplant. Collectively the data demonstrates the possibility of using pre-transplant metabolic signature for risk stratification of SCT recipients with respect to development of GVHD.

biochemistry↗