Recently, the research group of Professor Yan Li from the Department of Pharmaceutical Analysis, School of Pharmacy, Fudan University published a research article entitled “A Tractable Method for Rapid Quality Assessment of Therapeutic Antibodies in Harvested Cell Culture Fluid Based on FcγRIIIa Immobilized Magnetic Microspheres” in Analytical Chemistry. In this study, an integrated method for rapid quality assessment of ADCC-enhanced therapeutic antibodies in harvested cell culture fluid (HCCF) was established.

FcγRIIIa-binding affinity is one of the key factors to ensure the efficacy of many anti-tumor therapeutic antibodies, which should be monitored along with titer, protein aggregation and other critical quality attributes (CQAs). Conventional workflow for quality assessment of therapeutic antibodies in HCCF is time-consuming and costly nevertheless.

FcγRIIIa immobilized magnetic microspheres with polydopamine (PDA) and hydrophilic dendrimer (PAMAM) coating (denoted as Fe₃O₄@PDA@PAMAM-FcγRIIIa) were synthesized for the first time by Professor Yan Li 's research group. The novel Fe₃O₄@PDA@PAMAM-FcγRIIIa composites was applied as magnetic adsorbents to differentially extract IgG with different FcγRIIIa-affinity levels from complex HCCF samples in one step. The eluate could be directly subjected to size exclusion chromatography (SEC) analysis, and monomer peak area value in SEC, which was set as read-out of the proposed method, correlated directly with theoretic overall quality of standard-spiked HCCF samples

Figure. 1. Workflow of the Fe₃O₄@PDA@PAMAM-FcγRIIIa composites-based method for rapid quality assessment of therapeutic antibodies in HCCF samples.

Analytical time of the proposed method is estimated to be about 0.7 h per sample, which is 6 to 40-fold shorter than that of the traditional method. The Fe₃O₄@PDA@PAMAM-FcγRIIIa-based method can serve as an alternative approach for comparatively study or ranking of numerous HCCF samples according to the overall product quality profiles, taken titer, aggregation level and FcγRIIIa-affinity all into consideration.

PhD candidate Jianan Feng and Professor Yan Li from the Department of Pharmaceutical Analysis, School of Pharmacy, Fudan University are the first author and corresponding author, respectively. This work was supported by the National Natural Science Foundation of China.

Full text：https://pubs.acs.org/doi/10.1021/acs.analchem.2c01350