Numerical simulation of oxygen delivery in presence of hemoglobin hydrogel based oxygen carriers

Abstract

Before donor blood can be transfused into patients, the red blood cell have to go through a series of tests which takes up time. In emergency situations like accidents, it will result in delay in treatment. Red blood cells have standard shelf life of only 42 days and unable to be checked and sterilized for infective agents like HIV. Thus, due to the concerns regarding donor blood having impurities, these factors stimulated the development of hemoglobin hydrogel based oxygen carriers. According to many researchers, the investigation of immobilizing hemoglobin in a polymer as an artificial blood substitutes is progressive. Many experimental studies have been done on hemoglobin entrapped hydrogels, but so far no attempt has been made to study via mathematical modelling. Thus, the use of COMSOL Multiphysics model and the diffusion – reaction equation in this study to simulate the performance of hemoglobin immobilized hydrogels in variation of chemical and electrical fields. COMSOL simulations were done based on the diffusion – reaction equation with fixed charged density (1mM to 1000mM) and oxygen concentration (0.001mM to 1000mM) being the free variables. The effect of the free variables on the following are studied: electrical potential, concentration of hydrogen ions, concentration of hydroxide ions, concentration of sodium ions, and concentration of chloride ions. It was found that the hemoglobin entrapped hydrogel in the electrical field is worthwhile as it prove that the conductance of cell membrane is high when electric field is applied. The oxygen delivery simulation is constant till the point of reaction with the buffer solution. The buffer solution used in phosphate buffered saline (PBS). While within numerical errors, the Multiphysics model was able to simulate the oxygen delivery fairly well.