Specific to articular cartilage, early attempts at cryopreservation employed standard cryobiological techniques that incorporated controlled ice formation such as the 2-step cryopreservation process. Therefore, the establishment of a cryopreserved tissue bank of articular cartilage could provide a treatment option for patients with large joint defects while minimizing the concerns regarding infectious disease transmission and improving clinical outcomes by providing a large range of sizes to choose from, optimizing the operating conditions by allowing this surgery to be planned electively, and possibly matching for blood and HLA typing.Ĭryopreservation has been successful for various individual cells, ,, , including articular cartilage chondrocytes, , but application to larger tissues has been extremely difficult. Initially reports indicated that the chondrocytes could survive up to 42 days at this temperature but more recent investigations have demonstrated that these cells begin to deteriorate after 7–14 days at 4 ☌ thereby significantly limiting the application of hypothermic storage as an effective tissue banking method. This led to the development of hypothermic storage at 4 ☌. As safety concerns arose regarding the transmission of infectious diseases with tissue donation during the 1980s, the attractiveness of this treatment option waned because of the necessity of performing the transplantation within 24–72 h of death of the donor to maintain chondrocyte viability. Fresh osteochondral allografting was popularized by Gross in 1983 and has had reasonable success for large joint defects over long periods of time. Unfortunately, these treatment options are not indicated for larger cartilage defects ultimately resulting in joint instability and the development of OA.
Small articular cartilage defects can be treated with various techniques such as drilling, microfracture, mosaicplasty, autogenous chondrocyte implantation and matrix-associated chondrocyte implantation with variable success. To date there is no known cure for OA however, several risk factors have been identified including articular cartilage injury. Thus, prevention and treatment of OA are of paramount importance to society. Almost 60% of those afflicted will be younger than 65 years of age while it is estimated that a quarter of the world's population over the age of 60 suffer from significant joint pain and disability caused by osteoarthritis (OA), the most common form of arthritis. Arthritis is a leading cause of work disability, with an annual economic cost of $4.4 billion in Canada and $40 billion in the USA. Osteoarthritis (OA) results in a massive socioeconomic burden with major personal implications. This report documents successful vitrification of intact human articular cartilage on its bone base making it possible to bank this tissue indefinitely. Cell viability was 75.4 ± 12.1% determined by membrane integrity stains and confirmed with a mitochondrial assay and pellet culture documented production of sulfated glycosaminoglycans and collagen II similar to controls. After complete exposure, the cartilage was immersed in liquid nitrogen for up to 3 months.
To address this limitation, human knee articular cartilage from total knee arthroplasty patients and deceased donors was exposed to specified concentrations of 4 different cryoprotective agents for mathematically determined periods of time at lowering temperatures. Cryopreservation/vitrification is one method to enable banking of this tissue but decades of research have been unable to successfully preserve the tissue while maintaining cartilage on its bone base – a requirement for transplantation. Osteochondral transplantation is an effective treatment for large joint defects but its use is limited by the inability to store cartilage for long periods of time. Articular cartilage injuries do not heal and large defects result in osteoarthritis with major personal and socioeconomic costs.
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