Hybrid dressings of hydrophilic material and polymer foam

Inventors

Chatterjee, Ranjit

Assignees

Dristi LLC

Abstract

Disclosed are hybrid wound dressings that include at least one front layer of a hydrophilic absorbent material and at least one layer behind the front layer that is made of an open-celled polymeric foam made from high internal phase emulsions (HIPEs). The hydrophilic absorbent material may be a natural polymeric material; a synthetic, non-foam polymer; or a material like glass microfiber. Each layer has a rate of fluid absorption and a capillary suction pressure (CSP) for a working fluid like blood plasma. The CSP increases from the front layer toward the layers behind the front layer, such that fluid is drawn away from a wound.

Core Innovation

The invention relates to a wound dressing that includes a first layer of an absorbent hydrophilic material and a second layer of open-celled foam produced by polymerizing a high internal phase emulsion (HIPE). The first layer absorbs a working fluid while exerting a first capillary suction pressure (CSP), and the second layer absorbs the working fluid while exerting a second CSP. The second layer is generally homogeneous in internal structure and is adjacent to and in fluid communication with the first layer.

The wound dressing is defined so that the second CSP is greater than the first CSP, producing a directional increase in capillary suction pressure from the first layer toward the second layer. The description further supports configuring the dressing using additional open-celled foam layers, including intermediate layers, to tune the fluid absorption rates and CSP values across the dressing.

In another configuration, the invention includes a cover mesh, a first hydrophilic absorbent layer exerting a first CSP, one or more intermediate layers of open-celled synthetic polymer foam each having an individual CSP, and a rear layer of open-celled HIPE-derived foam. The individual CSPs of intermediate layers are greater than the first CSP and greater than the individual CSP of a prior intermediate layer, and the rear layer CSP is greater than the individual CSP of the rearmost intermediate layer. The layers are arranged to be adjacent and in fluid communication to establish fluid flow between layers and an increasing CSP relationship toward the rear.

Claims Coverage

The independent claims provide two main inventive frameworks: a two-layer dressing with a hydrophilic absorbent first layer and an adjacent HIPE-derived open-celled foam second layer having a higher CSP, and a multi-layer dressing that adds a cover mesh and progressively increasing CSP intermediate open-celled polymer foam layers culminating in a rear HIPE-derived open-celled foam layer with a higher CSP.

Across both independent claims, the inventive core is the use of adjacent layers in fluid communication where capillary suction pressure is increased across the dressing, using HIPE-derived open-celled foam as one of the CSP-enhancing layers and, in the multi-layer framework, progressively increasing CSP intermediate foam layers culminating in a higher-CSP rear HIPE foam layer.

Stated Advantages

Documented Applications

No documented applications found