| Following the development of the biotechnology, the research and the composing technology of the biochemistry field have been improving constantly. More and more kinds of medicine made of protein and polypeptide has been discovered or artificially synthesized. According to the preliminary investigation, there have been more than one hundred kinds of organism products under being in the stage of clinical experiment. But lots of different kinds of problems appears when the kinds of medicine are really going to be of actual use. Such as the immune original nature, the short half-life, easy to be of organic degradation by different kinds of protein, and the solubility is bad and so on. With the development of research, the biodegradable materials begin to be paid attention to, and its usage has been wider. As carriers, biodegradable materials contain many advantages such as the elixir type is more flexible, the security is higher, and it can carries many kinds of medicines and so on.By far, polymer materials can be degraded by commonly used organisms contained with protein and polypeptide which are mainly made synthetically. Among them, polylactic acid and its derivatives are most widely used. They have excellent biodegradability. This is due to ester bonds susceptible to hydrolysis or enzymatic in the main chain, which would be hydrolysis and produced into lactic acid, and finally formed to be water and carbon dioxide. This essay uses as entrapment polyglycolic-lactic acid (PGLA) and its multipolymer (PEG-PLGA). Developed in our laboratory antioxidant enzyme- material of micro balloon sphere of sub-hexapeptide, makes polyglycolic-lactic acid and its multipolymer a reliable biological safety because of its good biocompatibility (lactic acid and glycolic acid are both products of intermediate metabolism of tricarboxylic acid cycle ) and its definite mechanism of absorption and metabolism. It can be used in clinical trials in the future.Developed in our laboratory, peroxydase of haem prosthetic group is peroxydase of non-specific type. It has the function of scavenge of free radicals by reacting with hydro hydrogen peroxide. However, natural peroxidase is hard to compound, hard soluble in water and has poor stability, which limited its development as the antioxidant. Based on years of exploration, summaries and designs in our laboratory, new and ideal simulation of enzyme monomer-sub heme hexapeptide is synthesized and has determination of activity. In vitro experiment has proved that DhHP-6 can better simulate the activity of MP-11(microperoxidase-11)and has such excellent features as easy synthesis, easy purification, good water solubility and high stability, etc.Based on the package containing drugs DhHP-6 is water-soluble, while biodegradable polymer materials which is used in this paper is fat-soluble, thus, we choose widely used method polyester materials in fat-soluble contain water-soluble drugs to be microsphere, which is called complex emulsion solvent evaporation method to prepare drug-loaded microspheres.Complex emulsion solvent evaporation method to form the double emulsion is emulsified two times, also known as double-emulsion method. The typical preparation process is to add the drug solution into dichloromethane solution of polymer, emulsify to form into colostrums, and then pour it into water to emulsify again. Thus, the original polymer solution as continuous phase is dispersed in a large number of water to form droplets. Organic solvent in the emulsion will remove on its own after the processing of evaporation.Through materials and method above the drug-loaded microspheres PLGA and PEG-PLGA can be prepared. In which drug loading rate of PLGA can be 8.75%, drug release for 35% of the total in 7 days, then it come into sustained-release phase. The slow-release characteristic of PLGA is obviously to be seen. The drug loading rate of PEG-PLGA is higher than PLGA, which can reach 9.17%. However, such microspheres in the first day of the release come up burst release phenomenon, gradually level off and in the 5th day it can reach 33%, it also has reached the sustained-release effect. The reason for the burst release may be due to better water-soluble PEG-PLGA.This paper used the drug release of microspheres in vitro simulation of liquid, with the original drug as a control for enzyme activity and viability of such experiments to do drug-loaded microspheres molecular experiments. We first obtain solution in vitro degradation to test its efficient liquidity, in order to make sure the physical properties of drugs has not changed. Secondly, the test of enzyme activity indicates that drug-loaded microspheres prepared with the process after a fierce still retain most of the original drug activity. Finally, in the anti-oxidative damage model experiment, we prepared drug-loaded microspheres has anti-oxidant effect as the original drug, but a little weaker. These all show that some energy is lost during the preparation. So the drug microspheres preparation is still needed to improve in many areas.Finally, cerebral ischemia model of rats is used as the in vivo slow-release test. Because of PEG-PLGA better hydrophilicity, higher drug loading, shorter experimental period, such drug-loaded microspheres are used as injection group, comparing with the original one. The result shows that drug-loaded microspheres can protect brain for cerebral ischemia, survival longer compared with model group and the amount of DhHP-6 in drug-loaded microspheres is the same as original drug injection. So by the conclusion we can see that the rats which are injected drug-loaded microspheres can survival longer than the original drug injected group, which further shows that the drug-loaded microspheres in rats have a sustained-release effect and extend the life of rats.In a word, the initially drug-loaded microspheres preparation is effective. It retains most properties of the original drug, and also keeps sustained-release effect in vivo and in vitro, so the experiment reaches the desired results in the whole. However, there are some deficiencies in this paper. These need to be improved and strengthened in the future.This paper also lays an experimental foundation for further study of some other types of DhHP-6 drug preparations.
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