Studies On Pegylation And Biological Properties Of An Analogue Of Ciliary Neurotrophic Factor Rh-CNTF (A¹⁷R⁶³15)

Protein drugs have a good advantages of the specificity and pharmacodynamics . It has been widely used in the clinical therapeutics, but these drugs are still that there are some issues that will be addressed, such as drug delivery systems are imperfect, difficult-specific drug delivery ,low stability , easy to be degradated by enzymes, due to the rapid removal from the circulatory system so that it has a short half-life, low bioavailability in vivo. To solve these problems, scientists practiced two ways, the first is to find delivery means of a high bioavailability of protein drug ; the second is to use chemical modification to optimize the dynamics of protein metabolism to extend its half-life, to get more efficiency and stability.Chemical modification is means that protein will be modified at the molecular level, which will be attached some chemical groups to side-chain groups of proteins by artificial methods in the in vitro ,in particular, covalently connected with biocompatible macromolecule, to change the protein biological properties. Its main advantages are the extension half-life of target protein in the body to reduce the immunogenicity and antigenicity, can also weaken the role of protease hydrolysis, increase soluble molecules such as proteins. There are a lot of macromolecules used for modification protein such as polyethylene glycol, polysaccharides, protein homology, as well as synthetic peptides. Of these, polyethylene glycol has a better biocompatibility, a simple reaction , low price so that has been more attention.This test goal is that study on PEGylation of rh-CNTF to obtain a low immunogenicity, high stability of the monomer PEG-rhCNTF (A¹⁷R⁶³15), at the same time to improve the target protein pharmacokinetics and administration.In this study, the detailed contents we have accomplished and the conclusions we have gotten are shown as follows:1,The construction and purification of rh-CNTF (A¹⁷R⁶³15) ;2,The selection of eligible PEGylation reagents, the optimization and verification of technologies of PEGylation and purification by middle scale experiment;3,The establishment of methods of protein purification process of post-PEGylation and gaining the target protein, mono-PEG-rhCNTF (A¹⁷R⁶³15) ;4,The investigation of basic characteristics of mono-PEG-rhCNTF (A¹⁷R⁶³15) ;5,The investigation on the difference of immunogenicity and pharmacokinetics between PEG-rhCNTF (A¹⁷R⁶³15) and rh-CNTF (A¹⁷R⁶³15) , and the comparison on the pharmacodynamics.The studies above have laid the good foundation for developing the second generation long acting PEGylated drugs of rh-CNTF (A¹⁷R⁶³15) .