| Peroxidase enzyme is a kind of commonly used enzymes, widely used in clinical chemistry, environmental chemistry, biological analysis,food industry and other fields.DhHP-6 is a kind of peroxidase mimics.The peroxidase activity of DhHP-6 is very similar to that of HRP,but the price is only one-third of it.Developing the applications of DhHP-6 and replacing the traditional HRP is very important. In this thesis,we selected "completely natural circulation-type"biodegradable polymer-PLGA as carrier,immobilized DhHP-6 to solve the problems in practical applications.Since DhHP-6 possess the same active groups with Peroxidase.It has various biological activities including protection of murine ischemia reperfusion injury, improving cell survival and preventing apoptosis. However,DhHP-6 possess small half-lives. Their instability in the stomach and intestines, furthermore makes oral delivery difficult. Alternative administration by frequent injections is also tedious and expensive. Indeed the development of biodegradable polymeric microspheres has been seen as a promising way to overcome the administering problems of DhHP-6.In the last three decades, many therapeutic proteins and peptides have been microencapsulated in biodegradable polymers, mainly PLA, PCL, and PLGA. PLA and PLGA are biocompatible, biodegradable and approved by the FDA for certain clinical uses. Their degradation times can be varied from days to years by altering the type of polymer, the polymer molecular weight, or the structure of the microspheres. Moreover, biodegradable PLGA microspheres have also been demonstrated to be an excellent drug carrier for protein and piptide drugs.In the fiist part of this paper, a double emulsion solvent evaporative method for encapsulation of water-soluble DhHP-6 in microsphere was developed. The influence of the concentration of polymer, stabilizer PVA concentration and volume of internal water phase on microsphere characteristics.After Optimization, we get the encapsulation efficiency was 93.6%, compact structure, cumulative released 53.5% after two weeks in vitro. We found that in vitro release 16h DhHP-6 save more activities than that of HRP. It shows that DhHP-6 is more suitable than HRP using double emulsion solvent evaporation method to immobilize.In addition to encapsulated DhHP-6, we have also tried to covalent coupling DhHP-6 to PLGA, to enzymatic polymerization of phenol. Phenolic compounds are highly toxic pollutants generated by a variety of industries such as the manufacture. A modern approach to deal with the phenol wastes is by the use of enzymes. The most commonly applied enzymatic treatment for deactivation and detoxification of phenols involve peroxidases, in particular horseradish peroxidase (HRP). In the presence of hydrogen peroxide, HRP can oxidize phenolic compounds to phenoxyl radicals which then interact to create less soluble hydrophobicpolymeric products.In the second part of this paper,we attempted to use a new support-PLGA for immobilization of DhHP-6 for the purpose of phenol removal from a synthetic wastewater,for the fist time.We used DCC/NHS method for chemical coupling of DhHP-6 in PLGA,then prepared micropheres use this material. The application of immobilized DhHP-6 for the removal of phenol from aqueous solution was studied at different DhHP-6,PEG, hydrogen peroxide concentrations and reaction periods. The results show that through a reasonable process optimization immobilized DhHP-6 can effectively remove 80% phenol in middle concentration waste water, immobilized enzyme can also be recovered from the system.
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