Zhai Yanqin, Zhao Yongjiang, Lei Jiandu, Su Zhiguo, Ma Guanghui
National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China.
J Biotechnol. 2009 Jul 15;142(3-4):259-66. doi: 10.1016/j.jbiotec.2009.05.012. Epub 2009 Jun 2.
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.
重组人粒细胞集落刺激因子（rhG-CSF）及其聚乙二醇化产物“单聚乙二醇20-GCSF”已广泛用于治疗各种中性粒细胞减少症。然而，单聚乙二醇20-GCSF所需的高剂量使其在临床应用中相对昂贵。我们推测，具有较高聚乙二醇分子量（30 kDa聚乙二醇）的N端位点特异性聚乙二醇化rhG-CSF可能能够在保持其生物活性的同时实现更长的循环半衰期，从而减少临床使用剂量。rhG-CSF通过5 kDa、10 kDa、20 kDa和30 kDa的甲氧基聚（乙二醇）丙醛（mPEG-ALD）在N端进行聚乙二醇化，并对这四种聚乙二醇化产物在反应、分离、表征以及体内/体外活性方面进行了比较，结果表明，较高分子量的mPEG-ALD表现出更好的N端位点特异性选择性、分离纯度和产率。单聚乙二醇30-GCSF和单聚乙二醇20-GCSF的生产成本和体外活性几乎相同，而单聚乙二醇30-GCSF的体内循环半衰期更长，药物生物利用度比单聚乙二醇20-GCSF高60%。因此，单聚乙二醇30-GCSF在保持相同治疗效果的同时，给药剂量应低于单聚乙二醇20-GCSF。
