英夫利昔（Infliximab）已成为治疗炎症性疾病的重要生物药物，系统的PK/PD研究对其临床应用和质量控制至关重要。但体内Infliximab的血药浓度低、样品组成复杂且含有高同源性的IgG，如何精准富集体内样本中的Infliximab是临床血药浓度监测方面所面临的难题。本项目拟针对Infliximab的抗原结合片段通过计算机辅助筛选等技术设计特异性多肽配基；将多肽配基的特异性和聚合物整体材料的优异理化性质相结合开发特异性多肽修饰的高亲和整体富集柱；选取最佳的整体富集柱用于溃疡性结肠炎患者血清样品中Infliximab药物的精准富集与定量分析；通过与多种传统富集方法的系统比对研究，建立高效、高选择性的体内Infliximab精准富集纯化新策略。本项目的开展不仅为Infliximab的临床分析提供了新方法新技术，而且有望推动其它单抗精准富集策略研究，对生物药的生产研发和临床应用意义重大。

Infliximab (IFX), an immunoglobulin G (IgG) based tumor necrosis factor alpha (TNF-α) blocking antibody, has been developed for the treatment of several autoimmune diseases. However, many patients lose response to IFX therapy because of the inadequate drug level in blood or the formation of anti-drug antibodies. Therapeutic drug monitoring of IFX in patients' serum has shown great importance to these therapies. LC-MS/MS considered as the most promising monitoring technology still have to overcome some major challenges such as the low analyte concentrations and the interference of large amount of endogenous proteins. Previous studies found that antigen-binding fragment (Fab)-specific peptide ligands can specifically bind target mAb. Based on the complex of IFX-Fab and TNF-α, a biomimetic design strategy for Fab-specific peptide ligands of IFX was developed in this study. Peptide immobilized affinity monoliths were then designed here for the high-performance purification and quantification of IFX in complex sample matrices. After a systematically optimization and evaluation, an accurate and rapid enrichment method will finally be developed for the purification of IFX in patients' serum. Furthermore, different sample preparation methods for IFX were systematically compared in terms of their potential value and performance. Affinity enrichment method based on Fab-specific peptide ligands has many advantages over conventional precipitation and immunoaffinity chromatography, such as low cost, better ligand stability and longer life time etc. This research not only provides a tool for the PK/PD studies of IFX, but also shows great significance to the development of purification method for other mAbs.