Blood plasma is the yellow liquid component of blood, in which the blood cells of whole blood would normally be suspended. Blood plasma makes up about 55% of the total blood volume. Blood plasma is mostly water (e.g., about 90% by volume) and contains dissolved proteins, glucose, clotting factors, mineral ions, hormones, and/or carbon dioxide. Blood plasma is prepared by spinning a sample volume of fresh blood in a centrifuge until the blood cells fall to the bottom of a sample chamber. The blood plasma is then poured or drawn off. Blood plasma is frequently frozen fresh for future uses. Although frozen plasma is the current standard of care, there are numerous problems with such techniques. For example, the bag containing the frozen plasma may become brittle and be damaged during storage or transportation. Maintaining frozen plasma at the appropriate temperature during storage and transportation is very expensive. It requires mechanical freezers to keep the frozen plasma at about −18° C. or lower. Shipping requires special shipping containers to maintain the frozen state and reduce breakage of the bag. Use of the frozen plasma is delayed by 30-45 minutes due to the thawing time. Moreover, the preparation for use requires trained staff and specialized thawing devices in a regulated laboratory. Finally, fresh frozen plasma has a limited shelf life of 12 months at −18° C. Once thawed, the frozen plasma must be used within 24 hours.
In an attempt to avoid the disadvantages of frozen plasma, some have freeze dried (i.e., lyophilized) plasma. However, the freeze drying process produces a product composed of large, irregular sized grains or particles. Such products can be difficult or impossible to rehydrate to a form suitable for administration to a patient. Furthermore, the freeze drying process requires transfer of the product from the lyophilizer to the final container, thus requiring post-processing sterility testing. The freeze drying process can only be done in batch mode; continuous processing is not possible with freeze drying. Moreover, manufacturing scale-up requires changes to the freeze drying process, and there are protein recovery issues at scale up.
Accordingly, a need still exists in the field for plasma that may be stored in a wide range of environments without freezers or refrigerators, be available for use by first responders at the initial point of care, and can be transfused in minutes without the usual 30-45 minute delay associated with thawing of frozen plasma.
USPTO Backgrounds
USPTO Backgrounds