Abstract P117: A Mathematical and Physical Model for Non-Pulmonary Oxygenation for Resuscitation Utilizing Solid Peroxides
Introduction; Adequate tissue oxygenation is vital for resuscitation. Intravascular O2 carrying compounds may enhance tissue O2 delivery under ischemic conditions but use of both hemoglobin and nonhemoglobin O2 carriers have limitations. Use of compounds capable of producing O2 at the tissue level may be useful. Solid peroxides such as percarbamide may provide novel means of tissue O2 delivery since they contain stored O2 which can be released upon activation with catalase. However, the chemistry is complex and a product must be designed for controlled O2 production.
Objectives: To develop and use a mathematical and physical model to examine the feasibility of creating encapsulated solid peroxides for intravenous O2 delivery.
Methods: An O2 delivery vehicle combining percarbamide, a non-aqueous liquid carrier, and a biodegradable-compatible polymer coating was developed for controlled O2 production. Upon contact with plasma, water diffuses across the polymer coating to cause release of H2O2 from percarbamide. The H2O2 then diffuses back across the membrane into plasma reacting with the blood enzyme catalase to form O2 and water. A permeation cell system was constructed to validate the physical chemistry of this controlled O2 production approach. A mathematical model incorporating Fickian diffusion and shrinking surface kinetics was derived to model O2 production.
Results: The permeation cell experiments validated the physical chemistry approach of delivering O2 using encapsulated percarbamide. The mathematical model successfully predicted O2 release. Experimental and modeling results show that by tuning the coating thickness, coating type, non-aqueous carrier liquid, and solid peroxide size, the rate of O2 production can be precisely controlled. Percarbamide (150 gms) would produce 250 cc/min of O2 for 60 minutes to meet whole body metabolic demands.
Conclusions: A mathematical and physical model of O2 production was successfully created allowing manipulation of multiple variables related to releasing O2 from a solid peroxide delivery system. Experimental results validate the model’s accuracy. This work suggests the feasibility of using encapsulated solid peroxides to produce life sustaining amounts of O2 for intravenous tissue oxygenation.