TY - JOUR
T1 - Positively charged gold-silver nanostar enabled molecular characterization of cancer associated extracellular vesicles
AU - Liu, Yuan
AU - Zhang, Wei
AU - Phan, Thanh Huyen
AU - Chrzanowski, Wojciech
AU - Rodger, Alison
AU - Wang, Yuling
PY - 2020/12/28
Y1 - 2020/12/28
N2 - Direct surface-enhanced Raman scattering (SERS) has contributed to characterizing extracellular vesicles (EVs) by providing molecular signatures. However, little work has been done to understand the heterogeneity of EVs created by different methods or from different biological sources. Herein, we pioneered the use of positively charged gold-silver nanostars to explore the SERS profiles of different EVs. The physical features of EVs from cancer cells including size, concentration, morphology and surface potential have been characterized via nanoparticle tracking analysis, transmission electron microscopy and zeta potential. The results show that negatively charged EVs are attracted to positively charged gold-silver nanostar surfaces via electrostatic forces resulting in SERS spectra showing characteristic vibrational modes of the different components of EVs (i.e. proteins, lipids and nucleic acids). SERS data were complemented by other spectroscopic techniques including atomic force microscope-infrared spectroscopy, UV-Visible absorbance spectroscopy and fluorescence spectroscopy providing a more complete molecular picture of EVs. SERS signatures of EVs from different origins, batches, and isolation approaches were compared and analyzed. A statistical method (principle component analysis-linear discriminant analysis) was utilized to differentiate EV subtypes. Consequently, a desirable discrimination outcome for blind samples was obtained. This study provides novel insights to deepen our understanding of EV heterogeneity.
AB - Direct surface-enhanced Raman scattering (SERS) has contributed to characterizing extracellular vesicles (EVs) by providing molecular signatures. However, little work has been done to understand the heterogeneity of EVs created by different methods or from different biological sources. Herein, we pioneered the use of positively charged gold-silver nanostars to explore the SERS profiles of different EVs. The physical features of EVs from cancer cells including size, concentration, morphology and surface potential have been characterized via nanoparticle tracking analysis, transmission electron microscopy and zeta potential. The results show that negatively charged EVs are attracted to positively charged gold-silver nanostar surfaces via electrostatic forces resulting in SERS spectra showing characteristic vibrational modes of the different components of EVs (i.e. proteins, lipids and nucleic acids). SERS data were complemented by other spectroscopic techniques including atomic force microscope-infrared spectroscopy, UV-Visible absorbance spectroscopy and fluorescence spectroscopy providing a more complete molecular picture of EVs. SERS signatures of EVs from different origins, batches, and isolation approaches were compared and analyzed. A statistical method (principle component analysis-linear discriminant analysis) was utilized to differentiate EV subtypes. Consequently, a desirable discrimination outcome for blind samples was obtained. This study provides novel insights to deepen our understanding of EV heterogeneity.
UR - http://www.scopus.com/inward/record.url?scp=85098660078&partnerID=8YFLogxK
U2 - 10.1039/D0AY01770A
DO - 10.1039/D0AY01770A
M3 - Article
SN - 1759-9660
VL - 12
SP - 5908
EP - 5915
JO - Analytical Methods
JF - Analytical Methods
IS - 48
ER -