Tag: <span>cryopreservation</span>

This paper reviews the importance of maintaining low temperature storage and handling (i.e., cold chain) for animal serum through all stages of processing, from finished product to the actual end-user. This cold chain extends from serum manufacture through the irradiation process, during shipment back to the supplier post-irradiation, as well as storage at supplier, irradiation, and end-user facilities. Anecdotal experience and theoretical considerations emphasize the point that maintenance of the cold chain is necessary for preserving the performance of serum for cell culture and other applications…

Manufacturing

Cryopreservation is a desirable method for the long-term storage of human red blood cells (RBCs). Current protocols employ high concentrations of glycerol that must be removed from thawed RBCs prior to transfusion. Small-molecule ice recrystallization inhibitors (IRI) can protect RBCs from cryoinjury during the freezing and thawing process in the presence of reduced amounts of glycerol. Although reducing the concentration of glycerol during freezing reduces post-thaw deglycerolization times, thawed RBC units still require post-thaw processing. Herein, we report the cryopreservation of RBCs using the non-permeating cryoprotective agent (CPA) hydroxyethyl starch (HES) supplemented with small-molecule IRIs: (1) PMP-Glc (110 mM); and (2) pBrPh-Glc (30 mM). The results demonstrate that 30 mM pBrPh-Glc in 11.5 % (w/w) HES affords quantitative post-thaw recovery of intact RBCs that are superior to those obtained using glycerol with slow cooling rates, and show the utility of small-molecule IRIs in cryopreservation…

Cell & Tissue Banking

The success of tissue-engineered cartilage constructs (TECCs) as treatment options for healing cartilage defects can only be achieved if suitable preservation methods are found that can maintain their viability and function. Simply lowering the temperature of cells and tissues to below their freezing point invariably destroys them due to ice crystals that form in the water-laden cells and tissues. In addition, high salt concentrations that result from removal of water due to ice formation create a toxic imbalance. If the formation of ice crystals can be minimized while still halting metabolic activity of cells at low temperatures, then the viability and functionality of the preserved tissue may be maintained…

Biologics Production

Today, technology has reached a point where organisms (bacteria, plant and animal cells) can be genetically engineered to produce specific macromolecules and perform complex chemical reactions. Hence, they are called “cellular factories.” Cellular factories have applications in: biomedicine (e.g., implanted insulin secreting cells for the management of diabetes); biotechnology (recombinant protein and enzyme production for pharmaceutical and food industries); bioremediation (toxic waste and pollutant clean-up); green chemistry (production of chemicals with minimum toxic bi-product generation); alternative energy generation (electricity and hydrogen production by bacteria); biosensors (e.g., devices housing “canary cells”, which can signal the presence of pollutants, viral agents, or toxic chemicals); bioreactive devices (that can detect low concentrations of chemicals, etc.)…

Biologics Production Cell & Gene Therapy

Storage and shipping variables may significantly impact cryopreserved product quality. In this particular article, the focus is on temperature control issues. The AATB (American Association of Tissue Banks) Standards for Tissue Banking state that cryopreserved cardiac allografts shall be maintained at temperatures of –100°C or colder. Heart valves are usually stored below –135°C in vapor phase nitrogen. There have been few published studies of higher (warmer) storage temperatures. Most heart valves are transported using dry shippers that maintain vapor phase nitrogen temperatures. These containment devices are expensive, and the costs for two-way shipping are significant due to their size and weight. Considerable savings could be had if dry ice shippers with temperature excursions warmer than the AATB standard (of up to –70°C) could be employed…

Cell & Tissue Banking

Three types of heart valves are employed for replacement in patients: mechanical, xenogeneic tissue, and allogeneic human valves derived from donors post-mortem. The intention of this article is two-fold: 1) to place issues associated with the preservation of allogeneic human heart valves in perspective relative to the AATB Standards for Tissue Banking and current practices in US cardiovascular tissue-processing facilities; and 2) present potential opportunities for improvements with appropriate validation. Most patients receive either xenogeneic tissue or mechanical valves; however, the use of cryopreserved human valve allografts became established during the 1970s and 1980s for certain patient subsets…

Cell & Tissue Banking

Baculovirus, particularly AcMNPV (Autographa californica multiple nucleocapsids polyhedrosis virus), is widely used for heterologous protein expression. There are several shortcomings in the current practice of preserving and scaling up baculovirus: 1) extracellular baculovirus stocks, routinely prepared in large volumes and stored at 4º C, are often unstable; 2) laborious and time-consuming steps to amplify and titer the baculovirus stocks are often necessary, and generally recommended, for achieving consistent viral infection and protein expression; 3) once prepared, the baculovirus is suspended and stored in conditioned medium. Given the complex, undefined, and unstable nature of the spent media components, including proteases and nucleases, protein expression tends to vary even when steps are taken to titer the virus stock and adjust the amount of stock used for infection. Here, we will report a new method for preserving and scaling up baculoviruses that: 1) provides a new form of viral stock more stable than the traditional, extracellular stock; 2) eliminates the need for virus amplification and retitering; 3) drastically reduces the turn-around time and resources required for scale-up; and 4) improves yield and consistency in protein expression.

Baculovirus Expression Technology

The globalization and sustained growth of the biotechnology market has brought the issue of biological packaging to the fore, particularly for those companies invested in cell and tissue bioproducts, such as engineered tissues and cells used for cell therapy. Biological packaging can be defined as the sum total of the physical device, temperature regulating and monitoring systems, type of preservation solution, and storage protocol(s) necessary to maintain cells or tissues in a “state of suspended animation” during transport or storage. The ideal biological package provides for the transport of cells and tissues throughout the global marketplace while maintaining both the viability and the function of the biological system at levels equivalent to those measured prior to shipment. Cells and tissues are currently shipped and stored under hypothermic (4–8ºC) or cryopreserved (–80 to –196ºC) conditions. These two processes have remained relatively unchanged over the past several decades, limiting their utility in the storage of modern bioproducts. However, recent evolutions in biological packaging have begun to provide scientific and financial benefits to researchers, clinicians, and corporate entities…

Biologics Production Cell & Gene Therapy

A clinical-scale manufacturing process has been developed for the ex vivo expansion of autologous cytolytic T lymphocytes (CTLs) directed against cells infected with the hepatitis B virus (HBV). The process is based on the Rapid Expansion Method (REM) technology originally developed at the Fred Hutchinson Cancer Research Center in Seattle, WA by Greenberg and Riddell. Preparations are underway to initiate a company-sponsored Phase I clinical trial in which REM will be used to expand rare autologous HBV-specific CTLs that will then be infused to patients chronically infected with HBV. Earlier studies have shown that such patients mount only a weak CTL response to HBV. Chronic hepatitis B can lead to severe liver damage such as cirrhosis and hepatocellular carcinoma. By infusing clinical-scale quantities of autologous HBV-specific CTLs into chronic HBV patients, it may be possible to boost the immune system so that it can control the viral infection…

Biologics Production Cell & Gene Therapy Manufacturing

The K562 cell line is a human myelogenous leukemic cell which has been used by several groups, including ours, as a vehicle for cell-based vaccines and immuno-gene therapies. The attractiveness of K562 cells is the ease with which they can be cultured, plus the fact that they express very low levels of MHC proteins. Low MHC expression facilitates the use of these cells in patients with different MHC backgrounds, and it may improve the in vivo survival of the cells by delaying immune rejection. Based largely on these properties, we have been developing the K562 cell line as a universal platform for expressing cytokines, tumor antigens, and other immuno-modulating proteins…

Biologics Production