Immunomagnetic isolation and characterization of exosomes from tumor cells, embryonic kidney cells and human plasma using the free-flow magnetic chamber HOKImag

Among the heterogeneous family of extracellular vesicles, exosomes are by definition the smallest subspecies and are formed along the endosomal pathway. They participate in intercellular communication and appear to be closely connected to tumor development. Therefore, hopes are high that these vesicles offer future applications as biomarkers, drug delivery vectors and tools of intervention in tumorigenesis. In this context, a reliable method to purify exosomes from biological fluids is critical to any prospective clinical usage. 
Since there is currently no existing gold standard of exosome purification, this dissertation investigated an alternative method based on immunomagnetic isolation. 
Exosomes that had been labeled with magnetic nanoparticles linked to antibodies specific to exosome markers (CD9, CD63 and CD81) were successfully purified by HOKImag, a high-gradient and matrix-free magnetic device.
Initially, a combination of HOKImag and ultracentrifugation was demonstrated to be most effective compared to both isolation methods by themselves when purifying exosomes from MDA MB 231 cell culture supernatant. However, isolation by HOKImag solely still resulted in significantly greater enrichment of exosomes than ultracentrifugation by itself. To confirm the efficacy of HOKImag, exosomes from HEK 293 T cell culture supernatant were isolated in consecutive trials.
In a final step, the isolation method was transferred to human plasma and ultracentrifugation was omitted to facilitate the process. The resulting output material was found to be only enriched in CD9 and CD63 this time but respective transmission electron microscopy proved the isolation method successful nonetheless by displaying various vesicles coated with magnetic particles. 


Use and reproduction:

CC BY 4.0

Please note that individual components of the publication may be subject to other licensing or copyright conditions.


Citation style:
Could not load citation form.