Nanoparticle oxygen delivery to the ischemic heart.

Abstract

Currently there are no medications that can be administered to help deliver more oxygen to the myocardial region experiencing abnormal perfusion. The purpose of this study was to look at the nanoparticle dodecafluoropentane in an emulsion as an oxygen carrier. Using nanoparticles as an oxygen carrier is advantageous because they are able to carry oxygen past blockages that are obstructing red blood cells (6-8 µm) due to their smaller size (250 nm). With the reintroduction of oxygen to the ischemic muscle tissue, a reduced infarct size should be seen. Male C57BL/6J mice underwent left anterior descending artery (LAD) ligation using 8-0 monofilament nylon suture. Immediately after ligation of the LAD, the control group received a 200-µl intravenous injection of phosphate buffered saline (PBS). The treated group received a dose of 0.6 ml/kg of dodecafluoropentane diluted to a total volume of 200 µl in PBS. The mice were then allowed to recover from anesthesia and were sacrificed 24 hours after the time of ligation. After the mice were sacrificed, the heart was excised and placed at -20°C for 20 minutes. The heart was then sliced into 1-mm sections and stained with tetrazolium red to identify the infarcted area. The area of infarct and ventricle were then analyzed using ImageJ software. The average area of infarct in comparison to the ventricle for the control mice was 29.3±0.04% compared to 11.7±0.02% for the dodecafluoropentane-treated mice. The use of dodecafluoropentane in this murine model of myocardial infarction showed a 60% reduction in infarct size (p<0.01). The possibility of using nanoparticles to deliver oxygen to hypoxic tissues has interesting implications and justifies further study.