New non-chromatographic affinity matrices for antibody purification

抗体构成了制药行业中增长最快的部分。基于产品效价不断提高的优化生产工艺，对后续净化工艺的挑战也越来越大，这可能占总成本的80%。由于技术限制，色谱柱的体积不能扩大。更高的容量和更好的过程稳定性对色谱介质变得越来越重要。在以经典蛋白A为基础的亲和层析的平台过程中，这两个参数都达到了极限：必须找到新的替代品。由于抗体只需一步就能被亲和配体纯化，纯度高达95%，没有亲和配体就不可能有新的工艺。在以往亲和配体的基础上，通过选择非层析基质与新的高容量碱基稳定的蛋白A配体相结合，限制参数的挑战将被解决。通过无孔基质和经典层析介质的比较，将表明介孔不仅对传质限制有负面影响，而且对抗体的洗脱条件和聚集行为也有负面影响。由于其简单的可加工性，载体材料的选择落在两种不同类型的不同尺寸(微米/纳米)的生物兼容磁性颗粒上。根据大小的不同，它们具有相同甚至两倍的比表面积，有可能在每个载体单位结合更多的抗体分子，并在蛋白质纯化方面建立一个新的基准。此外，磁性纳米颗粒的生产比微粒和层析介质更便宜、更简单。

Antibodies form part of the most growing segment of pharmaceutical industry. Based on optimized production processes with increasing product titers the challenge for the subsequent purification process is also growing, which can account for up to 80% of the total costs. By technical limitations, the volumes of chromatography columns cannot be extended. Higher capacity and better process stability of the chromatographic media are becoming increasingly important. At the platform process with classical Protein A based affinity chromatography both parameters reached their limits: New alternatives have to be found. Since the antibodies are purified by affinity ligand in just one step with > 95 % purity and high yield, no new process could prevail without affinity ligands.Based on the previously unrivaled affinity ligands the challenge of limiting parameters will be solved by choosing a non-chromatographic matrix in combination of new high-capacity base-stabilized protein A-based ligands.By comparison of nonporous matrices and classical chromatographic media it will be shown that mesopores have not only a negative impact on mass transfer limitation but also on the elution conditions and aggregation behavior of antibodies. Because of their simple processability the choice of carrier materials falls on two different types of biocompatible magnetic particles of different size (micro / nano). Depending on the size, they have as much or even double specific surface area with the potential to bind more antibody molecules per carrier unit and to set a new benchmark in protein purification. Additional, magnetic nanoparticles are cheaper and simpler to produce than microparticles and chromatographic media.