title: Enhanced circulation half-life of site-specific PEGylated rhG-CSF: optimization of PEG molecular weight.
abstract: Recombinant human granulocyte colony stimulating factor (rhG-CSF) and its PEGylated product "mono-PEG20-GCSF" have already been widely used for treatment of all kinds of neutropenia. However, the high required dosage of mono-PEG20-GCSF made it relatively expensive in clinical use. We postulated that an N-terminal site-specific PEGylated rhG-CSF with higher PEG Mw (PEG30 kDa) might be able to achieve longer circulation half-life while retaining its bioactivity, allowing the reduction of dosage for clinical use. rhG-CSF was PEGylated at the N-terminus by 5 kDa, 10 kDa, 20 kDa and 30 kDa methoxy-poly(ethylene glycol)-propionaldehyde (mPEG-ALD), and the four PEGylates were compared with respect to reaction, separation, characterization and also in vivo/in vitro activity, results showed that the mPEG-ALD of higher Mw demonstrated better N-terminal site-specific selectivity, separation purity and yield. The production cost and in vitro activity of mono-PEG30-GCSF and mono-PEG20-GCSF were almost the same, while mono-PEG30-GCSF showed longer in vivo circulation half-life and 60% higher drug bioavailability than mono-PEG20-GCSF. Consequently, mono-PEG30-GCSF shall be administered at a lower dosage than mono-PEG20-GCSF while retaining the same therapeutic efficacy.
authors.affiliation: National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Yanqin
authors.initials: Y
authors.lastname: Zhai
authors.forename: Yongjiang
authors.initials: Y
authors.lastname: Zhao
authors.forename: Jiandu
authors.initials: J
authors.lastname: Lei
authors.forename: Zhiguo
authors.initials: Z
authors.lastname: Su
authors.forename: Guanghui
authors.initials: G
authors.lastname: Ma
mesh_terms: D000818:Animals; D001682:Biological Availability; D002850:Chromatography, Gel / Q000379:methods; D002852:Chromatography, Ion Exchange / Q000379:methods; D002942:Circular Dichroism / Q000379:methods; D004285:Dogs; D016179:Granulocyte Colony-Stimulating Factor / Q000097:blood* / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology; D006207:Half-Life; D006801:Humans; D008297:Male; D008970:Molecular Weight; D011092:Polyethylene Glycols / Q000737:chemistry / Q000493:pharmacokinetics* / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins
chemical_list: D011994:Recombinant Proteins; D016179:Granulocyte Colony-Stimulating Factor; D011092:Polyethylene Glycols