substantial limitations of light penetration in deep tissue. Even in small animals,
quantification of accumulated EVs in deep organs cannot be done using optical
imaging method. As radionuclide imaging is a noninvasive imaging method already
clinically widely used, radiolabeled EVs will play an important role in understanding the therapeutic EVs which is expected to be applied to clinical situation.
The firstly reported radiolabeling method was streptavidin-based radiolabeling
system.
125
I was successfully labeled to EVs and biodistribution study was performed. However, it required EVs extracted from the modified cells to express a
designed vector transfected. SPECT images of EVs were firstly reported by radiolabeling with
99m
Tc-HMPAO. The method was simple as it only mixed EVs with
clinically used
99m Tc-HMPAO under physiologic condition. Another simple
method for SPECT imaging using
99m
Tc-tricarbonyl was also reported. As EVs
have various areas of potential therapeutic uses including regenerative medicine,
cancer, inflammation and neurological disorders, flexible radiolabeling in various
biomedical application is needed. Radiolabeling based on click chemistry could
provide a simple, rapid, and multifunctional platform for the radiolabeling.
Appropriate chelators and combined radionuclides can be chosen according to the
purpose: SPECT, PET imaging or therapeutic/theranostic use.
In the future, EVs as multifunctional nanoparticles will be used in various fields.
As the application of EVs has gradually expanded, the need of quantitative imaging
will increase. EVs are highly diverse as they are originated from various cells and
conditions [50, 51]. The physiology of EVs will be different when they are
administered in vivo. Personalized tracking of EVs will be needed due to the
diversity of EVs. The flexible imaging platforms to trace EVs in vivo is required.
Efficient production of EVs combined with simple radiolabeling platforms under
physiologic conditions will facilitate theranostic application of EVs.
References
1. H. Choi, Y.-S. Lee, D.W. Hwang, D.S. Lee, Translational radionanomedicine: a clinical
perspective. Eur. J. Nanomed. 8(2), 71–84 (2016)
2. D.S. Lee, H.J. Im, Y.S. Lee, Radionanomedicine: widened perspectives of molecular
theragnosis. Nanomedicine 11(4), 795–810 (2015)
3. P. Vader, X.O. Breakefield, M.J. Wood, Extracellular vesicles: emerging targets for cancer
therapy. Trends Mol. Med. 20(7), 385–393 (2014)
4. S.M. van Dommelen, P. Vader, S. Lakhal, S.A. Kooijmans, W.W. van Solinge, M.J. Wood
et al., Microvesicles and exosomes: opportunities for cell-derived membrane vesicles in drug
delivery. J. Control Release 161(2), 635–644 (2012)
5. S. Ohno, M. Takanashi, K. Sudo, S. Ueda, A. Ishikawa, N. Matsuyama et al., Systemically
injected exosomes targeted to EGFR deliver antitumor microRNA to breast cancer cells. Mol.
Ther. 21(1), 185–191 (2013)
6. L. Biancone, S. Bruno, M.C. Deregibus, C. Tetta, G. Camussi, Therapeutic potential of
mesenchymal stem cell-derived microvesicles. Nephrol. Dial. Transplant. 27(8), 3037–3042
(2012)
7 Endogenous Radionanomedicine: Radiolabeling
149
quantification of accumulated EVs in deep organs cannot be done using optical
imaging method. As radionuclide imaging is a noninvasive imaging method already
clinically widely used, radiolabeled EVs will play an important role in understanding the therapeutic EVs which is expected to be applied to clinical situation.
The firstly reported radiolabeling method was streptavidin-based radiolabeling
system.
125
I was successfully labeled to EVs and biodistribution study was performed. However, it required EVs extracted from the modified cells to express a
designed vector transfected. SPECT images of EVs were firstly reported by radiolabeling with
99m
Tc-HMPAO. The method was simple as it only mixed EVs with
clinically used
99m Tc-HMPAO under physiologic condition. Another simple
method for SPECT imaging using
99m
Tc-tricarbonyl was also reported. As EVs
have various areas of potential therapeutic uses including regenerative medicine,
cancer, inflammation and neurological disorders, flexible radiolabeling in various
biomedical application is needed. Radiolabeling based on click chemistry could
provide a simple, rapid, and multifunctional platform for the radiolabeling.
Appropriate chelators and combined radionuclides can be chosen according to the
purpose: SPECT, PET imaging or therapeutic/theranostic use.
In the future, EVs as multifunctional nanoparticles will be used in various fields.
As the application of EVs has gradually expanded, the need of quantitative imaging
will increase. EVs are highly diverse as they are originated from various cells and
conditions [50, 51]. The physiology of EVs will be different when they are
administered in vivo. Personalized tracking of EVs will be needed due to the
diversity of EVs. The flexible imaging platforms to trace EVs in vivo is required.
Efficient production of EVs combined with simple radiolabeling platforms under
physiologic conditions will facilitate theranostic application of EVs.
References
1. H. Choi, Y.-S. Lee, D.W. Hwang, D.S. Lee, Translational radionanomedicine: a clinical
perspective. Eur. J. Nanomed. 8(2), 71–84 (2016)
2. D.S. Lee, H.J. Im, Y.S. Lee, Radionanomedicine: widened perspectives of molecular
theragnosis. Nanomedicine 11(4), 795–810 (2015)
3. P. Vader, X.O. Breakefield, M.J. Wood, Extracellular vesicles: emerging targets for cancer
therapy. Trends Mol. Med. 20(7), 385–393 (2014)
4. S.M. van Dommelen, P. Vader, S. Lakhal, S.A. Kooijmans, W.W. van Solinge, M.J. Wood
et al., Microvesicles and exosomes: opportunities for cell-derived membrane vesicles in drug
delivery. J. Control Release 161(2), 635–644 (2012)
5. S. Ohno, M. Takanashi, K. Sudo, S. Ueda, A. Ishikawa, N. Matsuyama et al., Systemically
injected exosomes targeted to EGFR deliver antitumor microRNA to breast cancer cells. Mol.
Ther. 21(1), 185–191 (2013)
6. L. Biancone, S. Bruno, M.C. Deregibus, C. Tetta, G. Camussi, Therapeutic potential of
mesenchymal stem cell-derived microvesicles. Nephrol. Dial. Transplant. 27(8), 3037–3042
(2012)
7 Endogenous Radionanomedicine: Radiolabeling
149