Wound dressings, methods and apparatus for making same and storage and use thereof
Inventors
Assignees
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Publication Number
US-9180142-B2
Publication Date
2015-11-10
Expiration Date
Abstract
Provided is a wound dressing prepared from whole blood that is clotted ex vivo to form a sheet of clotted blood that is applied onto the skin over a sight of skin injury.
Core Innovation
The document describes dressing wounds using ex vivo clotting of sterile whole blood to produce a sterile wound dressing comprising clotted whole blood and a support matrix. A volume of sterile whole blood is obtained by sterile withdrawal of venous blood from the subject, mixed with an anticoagulant, and then mixed with a coagulation initiator. The resulting whole blood is spread onto a support matrix at a location physically separated from the wound, after which the whole blood clots on the support matrix to form the sterile dressing.
The dressing formed at the physically separated location is then applied onto the wound, and is left in place for at least two days. The document also describes formation and handling of sterile sheets of clotted whole blood, with support structures such as gauze or mesh incorporated or supported, and handling concepts using a refrigerated clot bank with unique identifiers and cross-compatibility information for stored clotted materials.
The document connects the clot-sheet dressing to chronic, non-bleeding wound treatment, including chronic ulcers and skin burns. It also describes incorporation of anticoagulant and anti-anticoagulant combinations, coagulant and anticoagulant interactions in which kaolin is used to improve clot properties, and application modalities including wet or dry dressing modes and the use of conventional over-dressings or secondary dressings to maintain the dressing in place.
Claims Coverage
The provided independent claims cover two closely related methods: a general method of dressing a wound of a subject and a method specifically directed to dressing a chronic ulcer. Across these independent claims, four main inventive features are repeatedly emphasized: sterile withdrawal of venous whole blood, ex vivo mixing with anticoagulant and coagulation initiator followed by clotting on a support matrix at a physically separated location, application of the clotted whole blood and support matrix dressing onto the wound, and maintaining the dressing in place for at least two days.
Physically separated ex vivo clotting onto a support matrix
Spreading the volume of sterile whole blood onto a support matrix at a location physically separated from the wound; allowing the volume of sterile whole blood to clot on the support matrix at the physically separated location to form a sterile wound dressing comprising clotted whole blood and the support matrix.
Sequential mixing with anticoagulant and coagulation initiator
Mixing the volume of sterile whole blood with an anticoagulant; mixing the volume of sterile whole blood and anticoagulant with a coagulation initiator.
Sterile venous whole blood preparation and application to the wound
Obtaining a volume of sterile whole blood by sterile withdrawal of venous blood from the subject; applying the sterile wound dressing comprising the clotted whole blood and the support matrix onto the wound.
Dressing retention for at least two days
Leaving the sterile wound dressing in place for at least two days.
Chronic ulcer-specific dressing method
Applying the sterile wound dressing comprising the clotted whole blood and the support matrix onto the chronic ulcer, and leaving the sterile wound dressing in place for at least two days.
The independent claims are directed to a dressing method in which sterile venous whole blood is sequentially mixed with an anticoagulant and a coagulation initiator, then ex vivo clots on a support matrix at a location physically separated from the wound, producing a sterile dressing that is applied to the wound, including a chronic ulcer, and left in place for at least two days.
Stated Advantages
Provides wound healing outcomes reported in a human study, with complete healing observed in 5/7 wounds and more than 80% healing in 2/7 wounds, with no reported adverse events in the provided summary.
Documented Applications
Dressing chronic, non-bleeding wounds, including chronic ulcers and skin burns, using a sterile wound dressing formed by ex vivo clotting of sterile whole blood on a support matrix at a physically separated location.
Dressing a chronic ulcer of a subject for at least two days with the clotted whole blood and support matrix sterile wound dressing applied to the ulcer.
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