Hong Moo Sun, Lu Amos E, Bae Jaehan, Lee Jong Min, Braatz Richard D
Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States.
School of Chemical and Biological Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea.
Cryst Growth Des. 2021 Nov 3;21(11):6064-6075. doi: 10.1021/acs.cgd.1c00231. Epub 2021 Oct 18.
Crystallization is a potential cost-effective alternative to chromatography for the purification of biotherapeutic proteins. Crystallization kinetics are required for the design and control of such processes, but only a limited quantity of proteins is available during the initial stage of process development. This article describes the design of a droplet-based evaporative system for the evaluation of candidate crystallization conditions and the estimation of kinetics using only a droplet (on the order of μL) of protein solution. The temperature and humidity of air fed to a flow cell containing the droplet are controlled for evaporation and rehydration of the droplet, which are used for manipulating supersaturation. Dual-angle images of the droplet are taken and analyzed on-line to obtain the droplet volume and crystal sizes. Crystallization kinetics are estimated based on a first-principles process model and experimental data. Tight control of temperature and humidity of the air, fast and accurate image analysis, and accurate estimation of crystallization kinetics are experimentally demonstrated for a model protein lysozyme. The estimated kinetics are suitable for the model-based design and control of protein crystallization processes.
结晶是一种用于生物治疗蛋白纯化的、具有潜在成本效益的替代色谱法的方法。结晶动力学对于此类过程的设计和控制至关重要，但在工艺开发的初始阶段，仅有有限量的蛋白质可用。本文描述了一种基于液滴的蒸发系统的设计，该系统用于评估候选结晶条件，并仅使用微升量级的蛋白质溶液液滴来估算动力学。输送到包含液滴的流通池的空气的温度和湿度被控制，以实现液滴的蒸发和再水化，从而用于控制过饱和度。对液滴的双角度图像进行在线拍摄和分析，以获得液滴体积和晶体尺寸。基于第一性原理过程模型和实验数据估算结晶动力学。对于模型蛋白溶菌酶，通过实验证明了对空气温度和湿度的严格控制、快速准确的图像分析以及结晶动力学的准确估算。所估算的动力学适用于基于模型的蛋白质结晶过程的设计和控制。
