SBIR-STTR Award

The long-term objective of this proposal is to develop a safe and effective technique to deliver ATP directly to the human body and by-pass the body's need for oxygen. All cells of the body require oxygen and nutrients in order to make energy, and the energy is used to maintain homeostasis. Adenosine triphosphate (ATP) is the immediate source of energy that is constantly synthesized and metabolized in the body to maintain life. Without oxygen, ATP cannot be synthesized effectively in large quantities and thus the cells will die quickly from lack of energy and loss of homeostasis. Unfortunately many life-threatening conditions, such as heart attack, stroke, spinal cord injury, chronic obstructive pulmonary disease, and many surgical procedures all involve ischemia or hypoxia (low oxygen), which can cause reduced cellular energy and cell death. Over the years many attempts at restoring cellular energy have been unsuccessful, including direct intravenous infusion of ATP during ischemia. The major problem is that highly charged energetic phosphates, like ATP, do not pass through cell membranes and cannot be used for cell metabolism. The investigators have developed a new technique that delivers ATP and other high energy phosphates directly to cells, thus by-passing the need for oxygen. Our preliminary results indicate that our technique for delivering ATP can equal or supercede the cells need for ATP. Using this technique in a rat hindlimb preservation and transplantation model at room temperature, they can extend the preservation time of the severed limb to more than 20 hours, which is over 14 hours longer than previous attempts. This same technique has also been used by our company to extend heart preservation, and organism preservation. This Phase I proposal will further confirm our research concept and improve the effectiveness of our ATP delivery system. The aims are to: 1) further characterize the ATP delivery technique to improve the properties of the delivery vehicle (composition, dosage, temperature, concentration, and so on) to match the metabolic demand of different cell types; 2) study the cellular effect of this delivery technique in order to assess its toxic effects on cells; 3) study the method to deliver ATP not only to endothelial cells, but also to the cells outside of the vasculature by creating suitable gaps between endothelial cells; 4) to test the new ATP delivery technique in a composite tissue. The success of this project will have a huge impact on medicine and could change treatment strategies in many medical and surgical ischemic conditions.

Thesaurus Terms:
adenosine triphosphate, bioenergetics, biological transport, cellular respiration, metabolism, method development cell type, lipid biosynthesis, membrane transport protein biotechnology, laboratory rat

Adenosine triphosphate (ATP) is the universal energy currency of the body and is made in large amounts by cells using substrate and oxygen. In the absence of oxygen, such as in disease states or surgical procedures that affect oxygen delivery, sufficient amounts of ATP cannot be produced and life ceases. We have developed a solution which can deliver large and controlled amounts of ATP to cells and tissues using highly fusogenic lipid vesicles containing Mg-ATP (VitaSol) and thus significantly reduce the effects of ischemia. During knee surgeries and many extremity procedures, tourniquets are used to create a blood-free operation field. However, the use of tourniquets for periods in excess of 2 hrs significantly increases morbidity. The long-term goal of this project is to develop a safe and effective solution which can deliver ATP to tissues during tourniquet-induced ischemia and significantly decrease morbidity from reperfusion injury. This is a first step in eventually using VitaSol in many surgical procedures were ischemia or hypoxia are problematic. The ultimate goal is to be able to use VitaSol to decrease the effects of whole-body hypoxia. In Phase I, VitaSol was optimized and stabilized (as a freeze-dried powder), and we have proven its efficacy in maintaining animal viability and function in the absence of oxygen. We have maintained cells, tissues, organs, and organisms under hypoxia or chemical hypoxia (KCN) for periods of time that exceed any known method of preserving tissue. Composite tissues can be maintained viable for up to 21 hrs at room temperature with little or no loss in viability or function when perfused with VitaSol. In addition we can currently maintain rats for up to 1 hr without oxygen at normothermia or completely abolish the effects of an 8x lethal dose of IV injected KCN (2.5 mM). These and other exciting results clearly demonstrate the efficacy of this technique, and given that VitaSol(tm) has a shelf-life in excess of 12 months, will allow VitaSol to be tested to prevent the effects of tourniquet-induced ischemia. In Phase II of this proposal, we will optimize the delivery of VitaSol for tourniquet-induced ischemia, test VitaSol in a large vertebrate animal model of tourniquet-induced ischemia, and ready VitaSol for a Phase I clinical trial by running pre-clinical toxicity studies, preparing a pre-lND meeting, and producing VitaSol under cGMP. If the Phase II study is successful, VitaSol will be readied for a Phase I clinical trial. Once approved, VitaSol could be indicated for many other ischemic tissue procedures, such as free-flap surgery, limb replantation, resection of invasive tumors or lesions, repair of congenital anomalies, and bilateral extremity surgery. If these trials are successful and once we better understand its toxicity and efficacy, we will reenter VitaSol in trials for whole-body hypoxia.

Thesaurus Terms:
adenosine triphosphate, bioenergetics, biological transport, energy source, hypoxia, intracellular transport, ischemia, technology /technique development, tissue /organ preservation apoptosis, cell biology immunocytochemistry, laboratory rat, swine