The Neuroprotection Of Nanometer Perfluorocarbon Emulsion After Traumatic Brain Injury In Dogs

Perfluorocarbon (PFC)-based emulsions have been investigated as both oxygen therapeutics (blood substitutes) and contrast media. PFCs are biologically inert, fluorine-substituted hydrocarbon chains that have the ability to dissolve large amounts of gases, including O2 and CO2. Cerebral ischemia is a common secondary sequela of traumatic brain injury (TBI). Experimental models of stroke have emonstrated reductions in ischemia after perfluorocarbon (PFC) administration; however, there are less published reports of PFC efficacy after TBI.In 1966,Clark prove that perfluorocarbon emulsion possesses carrying the oxygen ability. The researches has been in progress to perfluorocarbon in nations such as the U.S.A, Japan, France and Germany etc, and some progress have been gained. PFCs are biologically inert, fluorine-substituted hydrocarbon chains that have the ability to dissolve large amounts of gases including O2 and CO2.These properties indicate a potential use for PFCs as red blood cell (RBC) alternatives after hemorrhage and to minimize tissue ischemiaIn 1972, Japan carried on the normal human body experiment, and the clinical experiment of PFC is carried on in Japan and U.S.A in 1979.But in this process of study and the application ,the fundamental research is clear inadequately, In TBI, the primary mechanical insult is followed by a complex cascade of secondary cellular events that lead to decreased cerebral oxygenation . Unlike the hemorrhagic shock, the reduction in tissue oxygen tension (ptiO2) after TBI is not attributable to RBC loss but rather to changes in dynamics of cerebral blood flow .This experiment use the new third generation carrying oxygen and nanometer type PFC, and this type PFC is composed by using the special type light source to carry on the actinic reaction, and choosing specially designated catalyzer and high efficiency refinement technology to separate and purify, and the outgrowth and raw material that does not react except clean ,the purity degree 99.5%. Uses the nanometer technology prepare the preparation, and gets the average granul diametre to control for 100 nanometers and even stable distributes latex. PFC possesses good chemistry stability and hot stability. This PFC carries oxygen ability 40-50mI%, about serve as the water 20 times, 2 times of blood. All not being destroyed in the acid and alkalescence solution, the change does not also occur in the heating . This preparation can stablely be stored under normal temperature, and can be exterminated bacterium under the high temperature and high pressure, and the peculiarity is not possessed in old type PFC.Objective: Establish TBI model to observe and view the function of effectiveness and safety of PFC in the course of treatment to TBI, and the function of protecting cerebral cortex nervecells.Methods: A totle 15 fifteen mongrel dogs, weight 21±5kg, were divided into a control group(9dogs) and an experimental group(6 dogs). The brain injury was made by a free weight strike on frontal-parietal lobe through a bone window in anaesthetized dogs. .Experimental group used PFC and control group used saline. In the course of treatment, all of dogs breath oxygen in veil. In the course of experiment, heart beat , breath rate, blood pressure, artery vigour, pupil light reflect, survival rate in 48hours are observed. To every sample, in the same parietal lobe cortex, with electron microscope and light microscope stucture is observed. Date were reported as mean±SD. Statistical significance levels were calculated by using Analysis of t test andκ² test.Results: In 24 hours survival rate in experimental group is higher than control group. The heart beat rate is not significantly different in both group. Breath in experimental group is deeper than control group and breath rate is also faster. In experimental group, blood pressure and PaO₂ is significantly higher than it in control group. PaCO₂ in experimental group evacuate higher than control group. The control group has the trand of going acid. Pupil light reflect in the experimental group is more sensitive than the control group. From light microscrope the parietal lobe cortex in experimental group are damaged less than control group, the structure and shape are almost normal, nucleolus clear; the neuron in control group swell, nucleolus extinct. The number of damage neuron is significant different in both group.Conclusion: The experiment research of this team of dogs about TBI indicates that nanometer PFC emulsions can significantly increase cerebral oxygenation and have remarkable neuroprotection after TBI by various ways. The experiment shows PFC is of one kind of effectively and safely neuroprotection. Neuroprotection of PFC can be applied in the clinician practice of brain ischemia.