Natural Wood‐Derived Macroporous Cellulose for Highly Efficient and Ultrafast Elimination of Double‐Stranded RNA from In Vitro‐Transcribed mRNA

Abstract Double‐stranded RNA (dsRNA) is a major impurity that can induce innate immune responses and cause adverse drug reactions. Removing dsRNA is an essential and non‐trivial process in manufacturing mRNA. Current methods for dsRNA elimination use either high‐performance liquid chromatography or microcrystalline cellulose, rendering the process complex, expensive, toxic, and/or time‐consuming. This study introduces a highly efficient and ultrafast method for dsRNA elimination using natural wood‐derived macroporous cellulose (WMC). With a naturally formed large total pore area and low tortuosity, WMC removes up to 98% dsRNA within 5 min. This significantly shortens the time for mRNA purification and improves purification efficiency. WMC can also be filled into chromatographic columns of different sizes and integrates with fast‐protein liquid chromatography for large‐scale mRNA purification to meet the requirements of mRNA manufacture. This study further shows that WMC purification improves the enhanced green fluorescent protein mRNA expression efficiency by over 28% and significantly reduces cytokine secretion and innate immune responses in the cells. Successfully applying WMC provides an ultrafast and efficient platform for mRNA purification, enabling large‐scale production with significant cost reduction.