Experimental Study On Preparation Of GM-1 PLGA Microspheres And Therapy Of Rat SCI Model

Objective:A great lot of extensive pharmacologic researching results suggest that monosialotetrahexosylganglioside(GM-1) possesses the intensive protective effects on spinal cord injury(SCI). The mechanisms probably include inhibiting the oxygen free radical excessive damage; reducing the inhibitive effects on Na+-K+-ATPase caused by spinal cord ischemia, decreasing the amounts glutamic acid and nerve cells apoptosis. It is known that the general peripheral medication route is hard to increase the local GM-1 consistence in the central nervous system. In recent years, researchers have confirmed that it could improve the therapeutic effect of SCI to inject GM-1 by subarachnoid medication route. Nevertheless the ordinary dosage form of GM-1 can't maintain the steady consistence in the injury area for a long time. And it is very difficult to effect that it is applied many times though local puncture. So it is very significant to study on sustained-release GM-1 PLGA microspheres and its valid function of protecting spinal cord injury.Materials and Methods:Preparation of microspheres experiment: We use a new type high polymer material PLGA as carrier material to prepare the sustained-release microspheres. The W/O/W double emulsion solvent evaporation-extraction method is used to prepare GM-1 PLGA microspheres. The different variables of influencing factors on the preparation technology of PLGA microspheres are optimized by single factor analysis experiments and uniform-design experiments. Prepare GM-1 PLGA microspheres under the optimized conditions, then determine the shape, particle size, drug loading amount, encapsulation efficiency and release profile in vitro.Animal experiments: 282 healthy adult SD rats of either sex half and half are randomly divided into four groups. Group A, B and C are spinal cord compression model(50g/5min)...