Polydiacetylene (PDA) Liposome-Based Immunosensor for the Detection of Exosomes

Abstract

Exosomes are extracellular vesicles (EVs) that have attracted attention because of their important biological roles in intercellular communication and transportation of various biomolecules, including proteins and genetic materials. However, due to difficulties in their selective capture and detection, further application of exosomes remains challenging. To detect EVs, we fabricated a liposomal biosensor based on polydiacetylene (PDA), a conjugate polymer that has been widely used in sensing applications derived from its unique optical properties. To confer selectivity and sensitivity to the sensory material, antibodies targeting CD63, a membrane protein exclusively found in exosomes, were attached to the PDA liposomes and phospholipid molecules were incorporated into the PDA vesicles. Signal analysis derived from PDA liposomes for exosome detection and quantification was performed by observing colorimetric changes triggered by the ligand–receptor interaction of PDA vesicles. Visual, UV–visible, and fluorescence spectroscopic methods were used to obtain signals from the PDA lipid immunosensor, which achieved a detection limit of 3 × 108 vesicles/mL, the minimum concentration that can be used in practical applications. The strategies used in the system have the potential to expand into the field of dealing with exosomes.

A rapid and highly sensitive biomarker detection platform based on a temperature-responsive liposome-linked immunosorbent assay

“…Our research is the first study to use temperature-responsive fluorescent liposomes as signal generators and amplifiers to detect target biomarkers. Previous studies which utilize liposomes as platform do not exhibit such unique optical property that signal intensity of liposomes, not targets, will drastically change under different circumstances, which is temperature in our case [30][31][32] . We used a special parameter, inflection time point, to identify the presence or absence of target molecules instead of fluorescence intensity difference as bound and unbound liposomes emit fluorescence at different time points under heating.…”

Highly Sensitive Polydiacetylene Ensembles for Biosensing and Bioimaging

“…Aside from the unique colorimetric property, the fluorescence of PDA has also attracted scientists' interest for a long time (Kobayashi et al, 1997;Lécuiller et al, 1999;Yamamoto et al, 2016;Roh et al, 2017;Cui et al, 2018b;Wang et al, 2018bWang et al, , 2020Kim and Lee, 2019;. Similarly, fluorescence of PDA will change when PDA transformed from blue phase to red phase.…”

“…Copyright 2007, Royal Society of Chemistry. Nsubuga et al, 2018;Stauber et al, 2018;Takeuchi et al, 2018;Heo et al, 2019;Jung and Park, 2019;Kim and Lee, 2019;Oh et al, 2019;Romero-Ben et al, 2019;Wang et al, 2019a;Zhang et al, 2019a;Adhikary et al, 2020;Fang et al, 2020;Hao and Zhu, 2020;Li et al, 2020;Tian et al, 2020). Our research group has also carried out some related work in this field.…”

Recent Progress on the Isolation and Detection Methods of Exosomes

“…In addition, some researchers also used CD63 protein on the surface of exosomes for specific recognition with corresponding antibodies to achieve quantitative analysis of exosomes. [53] The surface of exosomes is enriched with a large number of specific proteins. On the one hand, a single protein can be used to achieve the recognition and capture of exosomes; on the other hand, multiple specific proteins can also be used for multiple recognition and determination.…”