Improving on Army Field Gauze for Lethal Vascular Injuries: Challenges in Dressing Development J.V. Edwards, D.V. Parikh, P.S. Howley, S.L. Batiste, B.D. Condon Vision Bioconjugates Commercial Development

Cotton Chemistry & Bioactive Molecules Enzymes Peptides Carbohydrates Lipids Four classes of bioactive molecules Discuss with regard to cotton wound dressing research Enzymes are the catalysts of biological systems and have remarkable catalytic power and specificity. Peptide a subset of proteins. Are smaller than proteins and as a class of molecules have an incredible breadth of activities Carbohydrates are one of fuur major classes of molecules. Carbohydrates are aldehyde or ketone compounds with mutiple hydroxyls, and they make up most of the organic matter on earth. Cellulose is the most abundant carbohydrate in the bioshpere. Lipids have a variety of roles: they serve as fuel moelcules, signal molecules, and components of membranes.

Lethal Extremity Arterial Hemorrhage Half of all deaths on the battlefield are caused by uncontolled hemorrhage. High blood loss also causes, hypothermia, infection and multiple organ failure. Rapid hemostasis essential for survival and recovery.

Clotting Cascade

Swine Femoral Artery Assay

Swine Femoral Artery Assay

Ideal Battlefield Dressing According to USAISR Able to stop large vessel arterial and venous bleeding within 2 minutes of application when applied to an actively bleeding wound through a pool of blood. No requirement for mixing and pre-application when applied to an actively bleeding area. Simplicity of application by wounded victim, buddy, or medic. Light weight and durable. Long shelf life in extreme environments. Safe to use with no risk or injury to tissues or infection. Inexpensive.

Hemostatic Products Quickclot Chitosan Fibrin Sealant Army Field Dressing Is there any deployed product capable of stopping or reducing groin arterial bleed-ing and prevent exsanguination that otherwise could not be controlled by the stan-dard gauze dressing?

Cotton – Army Field Gauze Consists of two layers of gauze that wrap densely packed cotton. Absorbs a large volume of blood Cotton strands stimulate platelet aggregation and provide a matrix for blood clot formation Standard dressing for US Military units.

QuickClot A granular mineral zeolite that raplidly absorbs water in an exothermic reaction. In a wound, the reaction may concen-trate clotting factors and promotes hemo-stasis.

Fibrinogen Human fibrinogen, human thrombin Protein layers are freeze dried on Dexon mesh. Upon contact with the wound clotting proteins interact and from a fibrin layer. Adheres tightly.

Chitosan (Hemcon) Chitosan a derivative of chitin found in shellfish. Strong tissue ad-hesive properties that seal the wound and stop the bleeding.

Hemostatic Activity of Chitosan- Treated Cotton Gauze

Chitosan Grafted Nonwoven

Chitosan Sponge and Film

AFM of Chitosan Film

AFM Image of Chitosan Film

Comparing Chitosan and Aminized Cotton

Synthesis of Aminized Cotton

Performance of Dressings in Femoral Artery Assay

Results of Comparison

Survival Time Comparison

Granular Blend of Smectite and a Superabsorbent Nonwoven Ward, K.R., et al. J Trauma 2007; 63: 276-284.

Where are We to Date Towards Obtaining an Ideal Battlefield Dressing? Able to stop large vessel arterial and venous bleeding within 2 minutes of application when applied to an actively bleeding wound through a pool of blood? Yes No requirement for mixing and pre-application when applied to an actively bleeding area? Simplicity of application by wounded victim, buddy, or medic? Light weight and durable? Long shelf life in extreme environments? Safe to use with no risk or injury to tissues or infection? Yes Inexpensive?

Future Prospects