Cell And Tissue Systems, Inc. and Lifeline Scientific Inc. | Date: 2012-06-07
Methods for ex vivo perfusion of organs (and/or tissues) with a perfusate designed to condition the organ with the desired effect being that upon transplant, said organ, having been administered said perfusate, is less likely to experience delayed graft function, deleterious effects of ischemia/reperfusion injury, including inflammatory reactions, and/or other detrimental responses that can injure the organ or recipient including precipitating or enhancing an immunological reaction from the recipient with the potential of compromising the grafts and/or recipients short teen and/or long term health and proper functionality while monitoring, sustaining and/or restoring the viability of the organ and preserving the organ for storage and/or transport.
Agency: Department of Health and Human Services | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 224.93K | Year: 2013
ABSTRACT Obesity is a major global health issue. According to a recent report in the Journal of the American Medical Association non-Hispanic blacks have the highest age-adjusted rates of obesity (49.5%) compared with Mexican Americans (40.4%), all Hispanics (39.1%) and non-Hispanic whites (34.3%). However, genetics cannot account for the epidemic proportions of obesity in recent history. Environmental toxicants impact epigenetic programs of stem cell differentiation. Adipogenesis is among the best developed of differentiation assays and the genetic program of adipogenic differentiation is well characterized. Many obesogens have been shown to epigenetically regulate adipogenesis. We propose to develop an easy-to-use cryopreserved obesogenesis assay plate forsale and distribution. This assay plate will serve as a key reagent in the development of high-throughput predictive models for identifying and measuring biological response in humans to 'obesogen' toxicants. The assay plate will be pre-seeded with adipogenesis-responsive luciferase reporter- transduced preadipocytes, cryopreserved, shipped to customers, rewarmed and then used for direct, rapid, reproducible and sensitive testing of potential obesogens. This technology will help to prioritize chemicals formore extensive toxicological evaluation, support more predictive models of in vivo biological response, and permit assessment of preadipocytes (derived from human inducible pluripotent stem cells from individuals with different genetic or disease backgrounds). The proposed work in this Phase SBIR I feasibility study will be performed in 2 specific aims. In the first aim preadipocytes will be stably transduced with an adipogenesis- responsive dual-luciferase reporter system consisting of the 'Firefly' luciferase test and 'Renilla' luciferase positive reporters. These clones will be challenged in a standard adipogenic assay using replicate serial dilutions and combinations of two established obesogens. In aim 2 optimization experiments for the cryopreservation, storage and thawing of transduced and control adherent preadipocytes on 96 well assay plates will be performed. The assessment methods will include 1) cell viability and proliferation, 2) base line adipogenic differentiation, and 3) response to obesogen(s). Feasibility for progression to Phase II will be demonstration of gt70% viability, cell survival with retention of attachment to the tissue culture substrate, and functional adipogenesis-responsive reporter system post-thaw in 96 well plates. In PhaseII we will assess a broad range of potential obesogens employing our initial transduced clones and additional preadipocyte clones from individuals with different diseases and genetic backgrounds. We will also assess other multi-well plate formats for evenhigher throughput applications and, if necessary, further modify adipogenesis detection systems to increase the obesogenesis assay sensitivity. PUBLIC HEALTH RELEVANCE PUBLIC HEALTH RELEVANCE: According to the US Centers for Disease Control more than one-third of U.S. adults (35.7%) are obese. Obesity-related conditions include heart disease, stroke, type 2 diabetes and certain types of cancer, some of the leading causes of preventable death. In 2008, medical costs associated with obesity were estimated at 147 billion; the medical costs for people who are obese, and often socially disadvantaged, were 1,429 higher than those of normal weight. We propose to develop an easy-to-use obesogenesis assay plate that will serve as a key reagent in the developmentof high-throughput predictive models for identifying and measuring biological responses in humans to dietary and environmental chemicals that promote obesity. This technology is crucial if we are to address the current obesity epidemic, improve our overallhealth and reduce the health care costs associated with obesity.
Agency: Department of Health and Human Services | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 312.64K | Year: 2013
DESCRIPTION (provided by applicant): Resurfacing of articular cartilage with cold stored osteochondral allografts is employed clinically for repair of trauma and osteoarthritis-induced articular cartilage surface damage. Chondrocyte viability of transplanted articular cartilage is accepted as one of the determinants of outcome following osteochondral allograft transplantation. Refrigerated storage methods used for cartilage storage prior to clinical cartilage utilization need to be carefully evaluated because the tissue may be experiencing clinically significant deterioration during storage. We have recently investigated cartilage cell viability and matrix permeability during storage in culture medium, as well as storage solutions, and found that both deteriorate within the time frames that they are utilized for clinical procedures. Culture medium that preserves chondrocyte viability best under cold refrigerated storage conditions does not preserve matrix permeability and, vice versa, nutritionally deficientsolutions that preserve matrix permeability have significantly less cell viability. This objective ill be developed in three specific aims. In these aims two solution formulations, one based on intracellular and the other on extracellular milieu designs will be investigated. Chondrocyte viability, chemistry, biomaterial properties and gene expression will be compared over time during porcine cartilage storage. The gene expression studies will determine which formulation maintains normal untreated cartilageexpression of Sox9, aggrecan, collagen type II (versus dedifferentiation marker collagen type I), cartilage oligomeric matrix, a matrix resorption marker plus protein and hypertrophic marker genes. The solution that provides the longest preservation of chondrocytes with a normal untreated chondrocyte phenotype with minimal if any cartilage biomaterial changes will be selected for further investigation in vivo and translation to human cartilage in a subsequent Phase II SBIR application. PUBLIC HEALTH RELEVANCE PUBLIC HEALTH RELEVANCE: Both literature review and an independent survey performed for Cell and Tissue Systems indicates that there is a significant need for a cartilage preservation solution for clinical and research applications that maintains chondrocyte viability, phenotype and cartilage biomaterial properties. The impact of this research will be optimized preservation of both articular cartilage chondrocytes and biomaterial properties making transplants more effective in vivo. Commercialization of this cartilage storage technology will result in increased utilization of banked allogeneic cartilage for reconstruction of articular cartilage defects in younger patients. The solution will also be commercialized for cartilage storage for research and future tissue engineered cartilage products.
Agency: Department of Health and Human Services | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 224.81K | Year: 2011
DESCRIPTION (provided by applicant): Twenty four million Americans are affected with end-stage lung disease which is the 4th leading cause of death in the US, and there are currently 2,122 candidates on the lung transplant waiting list. Emphysema and chronic obstructive pulmonary disease are the most common diagnoses leading to lung transplantation. The limited availability of suitable lung donors has become an increasing concern in the transplant community. The primary impact of this SBIR proposal will beincreased numbers of lungs being considered acceptable for transplantation and decreased patient waiting times on the transplant list. This will be a consequence of technology focused on development of a lung hypothermic perfusion preservation device and methods that will maintain lungs ex vivo for up to 24 hours. Furthermore, the device should permit evaluation of organ quality; and it will also result in an important research tool being available to the lung research community. The objective of this PhaseI SBIR proposal is to determine the feasibility of hypothermic machine perfusion preservation of the lung by ex vivo normothermic testing of lung function after 12 hours in a portable hypothermic lung perfusion prototype. The portable lung perfusion prototype will be continuously optimized during the course of the experiments for optimal performance. Swine lungs preserved by hypothermic (4-8 C) perfusion for 12 hours will be compared with lungs submitted to cold static preservation on ice. Organ quality will be assessed ex vivo where the lungs will be perfused and ventilated at 37 C while biochemical and physiological tools are used to determine lung function. At the conclusion of this feasibility study the portable preclinical lung perfusion prototype design will be reviewed and subjected to failure mode and effects analysis to insure the safety and ease of use that will permit its clinical application. The proposed Phase I study will progress to Phase II if feasibility is demonstrated in Phase I. Feasibility will be verified by demonstration of statistically better lung function after perfusion preservation than current practice static storage controls. In Phase II porcine lung transplant model studies as well as ex vivo human lung evaluations will be performed. PUBLIC HEALTH RELEVANCE: This proposal aims at the technical breakthrough with the potential to address critical national needs for transplantable lungs. The device described in this proposal has the potential to increase the lung donor pool to levels that would satisfy current demand by evaluation, reconditioning and approval of marginal organs and controlled non-heart beating donors that are presently not considered for transplantation.
Agency: Department of Health and Human Services | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 278.18K | Year: 2011
DESCRIPTION (provided by applicant): Vascular grafting is performed clinically to repair or replace diseased coronary artery and peripheral vessels to restore normal blood flow patterns. Synthetic grafts composed of polymers such as Dacron and expanded polytetrafluoroethylene do not work well in small diameter (lt 6 mm) vessels. Such grafts exhibit low patency rates and fail, in large part, due to compliance mismatch. Compliance describes how the mechanical properties of a vascular graft change as a function of the internal hemodynamic pressure. Natural blood vessels display a complex non-linear 'J-shaped' stress-strain biomechanical behavior which is a function of extracellular matrix elastin and collagen nanofibers. Elastic fibers with straight conformation dominate the low elastic modulus at low levels of vessel distention. While collagen nanofibers with a wavy or helical orientation, with little resistance to expansion at lower values of vessel distention, dominate the high elastic modulus at higher levels of vessel distention as the nanofibers straighten. In addition to compliance, possession of a non-thrombogenic inner lining, biocompatibility and, after recipient cell ingrowth, vasoactivity is important for long term function of vascular grafts. The innovation in this proposal is design and manufacturing of composite nanofiber-based tissue-engineered vascular grafts (TEVGs) which mimic the potential implant site's arterial extracellular matrix microstructure and mechanical properties. In other words thegrafts will be designed to match the compliance of each type of artery that requires replacement. Our preliminary data has demonstrated our ability to fabricate synthetic nanofibrous composite materials with overall mechanical properties matching those ofa natural blood vessel (aorta) by employing a non-degradable elastin-like nanofiber and degradable collagen-like nanofibers. In this proposal these materials will be used in the construction of TEVGs mimicking the rabbit's carotid artery followed by evaluation in three specific aims. These aims include biomechanics and graft seeding with cells and in vitro assessment of remodeling profiles and retention of mechanical properties including compliance, burst strength and suture pull strength over time. Finally, cell-free TEVG designs will be assessed by vascular grafting in vivo. Patency, quantitative histology, mechanical properties and development of vasoactivity will be determined after one month post-implantation. Feasibility for progression to Phase II SBIR studies will be demonstrated by retention of biomaterial properties with e80% patency, the development of significantly better carotid-like vasoactivity after ingrowth of recipient cells and less anastomotic hyperplasia than controls (TEVGs without collagen-like microstructures) at explant. In Phase II we will propose large animal preclinical studies and other testing required for federal regulatory clearance for human trials. PUBLIC HEALTH RELEVANCE: Cardiovascular disease is a leading cause of patient morbidity and mortality. Effective small diameter vascular grafts are an unmet clinical need. The potential impact of this project is design and production of effective composite nanofiber-based tissue-engineered vascular grafts for patients requiring small diameter artery repair or replacement. The potential world-wide market for vascular grafts is predicted to be 1,657,000 units valued at 2,588M by the year 2013. The simplicity, versatility, and scalability of our proposed approach will allow rapidclinical translation and market penetration.
Agency: Department of Health and Human Services | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 185.90K | Year: 2011
DESCRIPTION (provided by applicant): More than 43,000 Americans die each year from liver disease, making it the 10th leading disease- related cause of death in the US. Cirrhosis with irreversible injury and scarring of the liver is the most prevalent causeof liver failure and is attributable to alcohol abuse as well as hepatitis. Although alcohol has been the primary cause of cirrhosis, the Center for Disease Control has predicted that hepatitis-related deaths will increase to 38,000 a year unless improvedtreatments are developed. The shortage of organs for transplantation continues to be a major impediment to providing optimal treatment for patients with end stage liver failure. There is no dialysis-equivalent therapy for these patients and the prospect of death while waiting for a transplantable organ is a realistic probability. The long-term goal of this SBIR proposal is to increase the number and quality of donor livers available for transplantation by developing a clinically usable, portable, hypothermic perfusion method of liver preservation that will reliably preserve human livers for at least 24 hours. The device can also be employed for liver quality evaluation ex vivo under physiologic conditions. The objective of this Phase I proposal is to test and determine feasibility of an intermediate near room temperature, 18-22oC, deep hypothermic oxygenated blood perfusion strategy in combination with a prototype liver transport device for preservation of porcine heart beating donor liver functions for 24 hours. This device concept has potential advantages compared with both normothermic and profound, 4-6oC hypothermic preservation strategies. The prototype liver transport device will be subjected to design review to optimize its design during the course ofthese experiments. The experimental livers will be compared with control livers stored on ice using current clinical methods. Both controls and experimental hypothermic perfusion groups will be assessed by oxygenated blood perfusion ex vivo at 37oC. The normothermic perfusion test circuit will include the liver transport device with additional heat exchange and oxygenation capacity. During testing perfusate and bile samples will be collected at frequent intervals and prioritized end point assays performed to measure (1) metabolic acidosis and hypoglycemia, (2) reduced or absent bile production, (3) Kupffer cell activation, and (4) sinusoidal endothelial cell dysfunction which would lead to reduced blood flow upon reperfusion. If we are successful in this Phase I feasibility study, we will subsequently propose a Phase II study in which porcine liver preservation for 48 hours is attempted and ex vivo and in vivo testing is combined with perfusion solution optimization. Forty-eight hours of porcine liver preservation would provide preclinical safety and efficacy data to support progression, with FDA permission, to clinical studies of human livers for up to 24 hours of preservation. PUBLIC HEALTH RELEVANCE: The innovative technical breakthroughs in this proposal will have a significant impact on critical national needs for transplantable livers. Conservatively the availability of longer term liver preservation strategies post-mortem may generate significant numbers, equivalent to ~25% more transplantable livers, from expanded criteria heart beating donors and short-term warm ischemic non-heart beating donors. This increase in organ supply should decrease patient waiting times for organs and the number of patients who die waiting for a liver.
Agency: Department of Health and Human Services | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 312.03K | Year: 2011
DESCRIPTION (provided by applicant): There is a worldwide consensus that islet transplantation may be considered a viable option for the treatment of insulin-dependent diabetes mellitus, and clinical trials are underway at many centers around the world. Asthis approach for curing diabetes transitions into a routine clinical standard of care so the demand for donor islets will escalate. Moreover, the potential for xenotransplantation to relieve the demand on an inadequate supply of human pancreases will also be dependent upon the efficiency of techniques for isolating islets from the source pancreases. Unfortunately, islets are highly vulnerable to irreversible damage after prolonged ischemia, and cold ischemia of the cadaveric pancreas is detrimental to islet yield such that new approaches are needed for improved methods of pancreas preservation to increase the yields of high quality islets. Hypothermia has proved to be the bed-rock of the most widely used methods of organ preservation but the best techniques are still subject to some cold ischemic injury. Oxygen deprivation is still regarded as a key factor and one strategy adopted to try to reduce the oxygen debt during ischemia has been to use perfluorocarbons (PFC) in an attempt to augment oxygen deliveryto the cold ischemic organ. However, the Two-Layer Method, in which the organ is submerged at the aqueous/PFC interface, has only proved successful in small animal models. As an alternative approach the hypothesis underpinning this proposal is that PFCs will need to be perfused into the organ to provide effective oxygen delivery to the hypoxic cold ischemic cells. The general aim of the proposed research is to combine three technologies that could impact the quality of donor organs, and notably pancreases.These are: i) hypothermic machine perfusion (HMP); ii) hypothermic blood substitution (HBS); and iii) oxygenation with perfluorochemicals (PFC). Our hypothesis that HMP with PFC-augmented HBS will provide superior hypothermic preservation of pancreases will be tested using two specific aims: The first aim will be to establish perfusion dynamics with Unisol-PFC, where Unisol is a proprietary HBS. Using an established porcine model, our baseline technology of HMP with Unisol HBS will be adapted to prepare anemulsion of PFC in Unisol (Unisol-PFC) and the perfusion parameters necessary to facilitate efficient perfusion will be determined using a LifePort(R) perfusion machine. The second aim will be to evaluate the efficacy of PFC-perfusion on the quality of post-perfusion isolation of islets. Using an established model of split-lobe perfusion the goal will be to compare the yield and quality of islets isolated from porcine pancreas lobes perfused with Unisol-PFC compared with Unisol alone. The anticipated outcome of this approach is that the implementation of PFC-augmented perfusion will provide a sustainable reservoir of O2 to meet the markedly reduced demands of the organ during extended cold ischemic storage. In turn, this will provide the means for high energy phosphate regeneration and avert the well recognized consequences of anaerobic glycolysis that the organ is forced to switch to during hypoxia and ischemia. While these studies are specifically designed to focus on the clinical need in islet transplantation, the underlying technology developments will be readily applicable to all transplantable organs. PUBLIC HEALTH RELEVANCE: Insulin-dependent diabetes is one of the major health problems worldwide and there is a great deal of interest in developing a potential cure by transplantation of islet cells isolated from a donor pancreas. A critical component of this approach is the availability of sufficient high quality islets to reverse diabetes in the patient. Current methods of storing organs prior totransplantation, or storing the pancreas prior to islet isolation, rely on hypothermic preservation modalities in which the organ still endures some injury from oxygen deprivation. This research is focused on the development of a new alternative techniqueto sustain oxygen delivery to the organ using perfusion technology with new inert oxygen-carrying solutions.
Agency: Department of Health and Human Services | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 224.00K | Year: 2014
DESCRIPTION (provided by applicant): Storage of cells for many researchers simply involves addition of 10% DMSO or similar cryoprotectants to cells in suspension, putting them in cryovials and slow cooling to subzero temperaturesf and storage in a mechanical or nitrogen cooled freezer or dewar. As long as viable cells are present upon thawing, cell yield may be a secondary consideration due to the high proliferative potential of the cells. However, there are significant cell types that are difficult to preserve with existing cryopreservation techniques including many primary cells, such as cardiac myocytes, and hepatocytes, plus embryonic stem cells and inducible pluripotent stem cells. Others, such as keratinocytes, are easy to cryopreserve in suspension but difficult when attached to a substrate. The study of how organisms survive extreme temperatures has revealed that multiple phenomena may occur in synchrony to promote survival including production of cryoprotectants, antifreeze compounds (peptides a
Agency: Department of Health and Human Services | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 268.56K | Year: 2012
DESCRIPTION (provided by applicant): In modern day medicine, cellular therapies, regenerative medicine and tissue engineering all involve technologies for harvesting, expanding, modifying and re-implanting live viable cells and tissues. Processes for preparing the therapeutic products that incorporate living cells are critical for the stability and potency of th products but may be inherently injurious to the component cells. For example, the widely practiced technique of collagenase digestion of tissues toobtain isolated cells such as pancreatic islets from pancreata, or hepatocytes from liver is fraught with detrimental side-effects and other associated problems. This widely practiced procedure has recognized pitfalls due principally to the difficulty ofcontrolling the digestive process to yield an optimum quantityof viable cells. Moreover, the process is harsh and even toxic, causing some inevitable loss of valuable cells. Furthermore, the process relying upon the purest forms of the enzymes are very expensive and may be subject to batch variations that have led to frustrating variability and inconsistency in attempts to optimize and standardize these processes. A totally new approach is proposed here that minimizes and potentially eliminates the need forenzymatic digestion of the tissue. Instead, the proposed process relies upon known susceptibilities of cells to freezing injury, to affect the separation of different cell types by virtue of a facilitated differential frezing and cryopreservation techniques. Feasibility for this novel approach has been demonstrated for isolating porcine pancreatic islets, which is a widely accepted model for research into the treatment of type I diabetes by islet transplantation. To obtain islets for cell-based therapies,te field of islet transplantation relies totally upon enzymatic digestion processes that destroy the extracellular matrix of the donor tissue releasing the entrapped islets for further processing and purification. In contrast, we propose to pre-treat the pancreas by differential perfusion of the endocrine and exocrine tissue in a way designed to maximize the destruction of the exocrine tissue at the same time as preserving the islets. More specifically, this new cryo-isolation approach involves an initial perfusion of the endocrine tissue (islets) with cryoprotective agents via a vascular access and after adequate equilibration of the islets only, the exocrine component (acini) is infused with a purely aqueous solution (distilled water or saline) via the ductal system The entire pancreas is then cooled under conditions that promote ice formation and destruction of the acinar tissue while preserving the endocrine portion by virtue of the cryoprotectant infiltration. The solid frozen pancreas is then amenable to indefinite storage and biobanking and subsequent processing to pulverize and fracture the gland into tiny fragments containing the cryopreserved islets. Finally, the freeze-disrupted tissue is thawed to release functional islets and destroyed acinar tissue. Having completed the initial proof-of-concept of this innovative new approach, this Phase I study proposes to develop a device prototype for cryo-isolation and evaluate its performance to establish baseline protocols. The approach combines basic research tools with recent advances in cryobiology science to systematically optimize the baseline technique, while developing a method to promote tissue fracturing by means of thermo-mechanical stresses, thereby increasing the effectiveness of differential freeze disruption and viable islet isolation. The study brings together a unique combination of expertise in cryobiology and thermo-mechanical engineering necessary to take this novel concept from feasibility to routine practice and subsequently validation inhuman tissue in a Phase II study. PUBLIC HEALTH RELEVANCE: Cell-based therapies in regenerative medicine and tissue engineering, which all involve processes for procurement and re-implantation of living cells, currently rely upon expensive, inconsistent and even toxic enzyme-digestion processes. A prime example is the preparation of isolated pancreatic islets for the potential treatment of Type I diabetes by transplantation. This research is focused on the development of a new and novel alternativetechnique to enzymatic digestion by relying instead on differential freeze destruction of the pancreas to release islets that are selectively cryopreserved in situ.
Agency: Department of Health and Human Services | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 262.00K | Year: 2012
DESCRIPTION (provided by applicant): Autologous regenerative medicine tissue therapy costs are very high because when individual tissues are manufactured all the costs fall on a single patient. Allogeneic tissues are cheaper because large tissue batches can be made and the costs are shared by many patients. Allogeneic tissues are commonly treated to remove cell-associated antigens by decellularization. Decellularization employs harsh chemicals and freezing methods that may damage tissue matrices. Our preliminary data in an in vivo allogeneic sheep model and an in vitro xenogeneic model with ice-free cryopreserved porcine tissue and human responder cells indicates that an ice- free cryopreservation method developed by the Company modifies the recipient's immune reaction. The primary goal of this SBIR proposal is a feasibility study to determine whether ice-free cryopreservation of human tissue also results in little or no immune reaction when combined with allogeneic human peripheral blood mononuclear cells using a panel of in vitro assays. This goal will be pursued in two Specific Aims and associated Hypotheses. The human tissues will be a tissue engineered vascular graft being developed by our collaborators for therapeutic applications. In the first aim cellular grafts will be ice-free cryopreserved and washing procedures to optimize cryoprotectant removal will be developed. Endothelial cell attachment and proliferation on the treated human tissue engineered vascular grafts will be the criteria for assessmentof washing adequacy. It is critical that the ice-free tissues be non-toxic to recipient cells for integration in to the recipient. Nanoliter osmometry will also be employed to quantify residual cryoprotectant concentrations. In the second aim evaluation ofimmunogenicity will be performed using cell proliferation and cytokine release assays. Fresh untreated, decellularized and ice-free cryopreserved human engineered blood vessels will be compared using allogeneic human peripheral blood mononuclear cells asresponders in vitro. The anticipated outcome is that the ice-free cryopreserved tissues will be equivalent or less immunogenic compared with decellularized controls. This outcome will be followed by in vivo transplant studies in a subsequent Phase II SBIRproposal. Retention of materials properties will also be confirmed in Phase II. This research will have a far-reaching clinical impact on surgical repairs by providing unprecedented access to low cost non- immunogenic tissue allografts for a variety of surgical applications and diseased artery replacement in particular. Our commercialization strategy involves exclusive and non-exclusive licensing of ice-free cryopreservation methods to companies developing specific human allogeneic tissue-based therapies.PUBLIC HEALTH RELEVANCE: Natural and engineered allogeneic tissues potentially impact huge orthopedic, urinary, cardiac and vascular surgery applications. The potential worldwide market for vascular grafts alone is predicted to be 2,588M in 2013. The technology development in this proposal will minimize costs by reducing the manufacturing steps required for engineered human tissue-derived products to be non-immunogenic. This technology simultaneously provides a long-term tissue storage method, whichhas proven retention of extracellular matrix components and biomaterial properties compared with alternative preservation strategies, with the potential for little if any immune response in vivo after implantation in patients.