cross section of the probes. To date, many efforts have been devoted to enhancing
the QYs, but not very satisfactory. Third, elimination time of NIR-II probes last for
weeks to months, and for large-sized nanoparticles, the excretion takes a longer time,
varying from months to years. It has been suggested that small-sized NIR-II
probes excreted by the renal route performed faster excretion. Therefore, further
work is required in developing suitable strategies to effectively expand the existing
NIR-II fluorescence imaging applications in vasculature visualization, disease
identification, and diagnostics.
Acknowledgments This work was partially supported by the fund from the Department of
Radiology, Stanford University.
Compliance with Ethical Standards
Funding: This work was partially supported by the fund from the Department of Radiology,
Stanford University; the Office of Science (BER), US Department of Energy (DE-SC0008397) and
the Shenzhen Basic Research Project (JCYJ20170817094201000).
Conflict of Interest: The authors declare that they have no conflict of interest.
Ethical Approval: This chapter does not contain any studies with human. All institutional and
national guidelines for the care and use of laboratory animals were followed.
References
1. Kunjachan S, Ehling J, Storm G, Kiessling F, Lammers T (2015) Noninvasive imaging of
nanomedicines and nanotheranostics: principles, progress, and prospects. Chem Rev 115
(19):10907–10937
2. Smith BR, Gambhir SS (2017) Nanomaterials for in vivo imaging. Chem Rev 117(3):901–986
3. Wang X, Pang Y, Ku G, Xie X, Stoica G, Wang LV (2003) Noninvasive laser-induced
photoacoustic tomography for structural and functional in vivo imaging of the brain.
Nat Biotechnol 21(7):803–806
4. He S, Song J, Qu J, Cheng Z (2018) Crucial breakthrough of second near-infrared biological
window fluorophores: design and synthesis toward multimodal imaging and theranostics.
Chem Soc Rev 47(12):4258–4278
5. Chernov KG, Redchuk TA, Omelina ES, Verkhusha VV (2017) Near-infrared fluorescent
proteins, biosensors, and optogenetic tools engineered from phytochromes. Chem Rev 117
(9):6423–6446
6. Hong G, Antaris AL, Dai H (2017) Near-infrared fluorophores for biomedical imaging.
Nat Biomed Eng 1:0010
7. Sordillo LA, Pu Y, Pratavieira S, Budansky Y, Alfano RR (2014) Deep optical imaging of
tissue using the second and third near-infrared spectral windows. J Biomed Opt 19(5):056004
8. Antaris AL, Chen H, Cheng K, Sun Y, Hong G, Qu C, Diao S, Deng Z, Hu X, Zhang B et al
(2015) A small-molecule dye for NIR-II imaging. Nat Mater 15(2):235–242
9. Carr JA, Franke D, Caram JR, Perkinson CF, Saif M, Askoxylakis V, Datta M, Fukumura D,
Jain RK, Bawendi MG et al (2018) Shortwave infrared fluorescence imaging with the clinically
approved near-infrared dye indocyanine green. Proc Natl Acad Sci 115(17):4465–4470
118
S. He and Z. Cheng
the QYs, but not very satisfactory. Third, elimination time of NIR-II probes last for
weeks to months, and for large-sized nanoparticles, the excretion takes a longer time,
varying from months to years. It has been suggested that small-sized NIR-II
probes excreted by the renal route performed faster excretion. Therefore, further
work is required in developing suitable strategies to effectively expand the existing
NIR-II fluorescence imaging applications in vasculature visualization, disease
identification, and diagnostics.
Acknowledgments This work was partially supported by the fund from the Department of
Radiology, Stanford University.
Compliance with Ethical Standards
Funding: This work was partially supported by the fund from the Department of Radiology,
Stanford University; the Office of Science (BER), US Department of Energy (DE-SC0008397) and
the Shenzhen Basic Research Project (JCYJ20170817094201000).
Conflict of Interest: The authors declare that they have no conflict of interest.
Ethical Approval: This chapter does not contain any studies with human. All institutional and
national guidelines for the care and use of laboratory animals were followed.
References
1. Kunjachan S, Ehling J, Storm G, Kiessling F, Lammers T (2015) Noninvasive imaging of
nanomedicines and nanotheranostics: principles, progress, and prospects. Chem Rev 115
(19):10907–10937
2. Smith BR, Gambhir SS (2017) Nanomaterials for in vivo imaging. Chem Rev 117(3):901–986
3. Wang X, Pang Y, Ku G, Xie X, Stoica G, Wang LV (2003) Noninvasive laser-induced
photoacoustic tomography for structural and functional in vivo imaging of the brain.
Nat Biotechnol 21(7):803–806
4. He S, Song J, Qu J, Cheng Z (2018) Crucial breakthrough of second near-infrared biological
window fluorophores: design and synthesis toward multimodal imaging and theranostics.
Chem Soc Rev 47(12):4258–4278
5. Chernov KG, Redchuk TA, Omelina ES, Verkhusha VV (2017) Near-infrared fluorescent
proteins, biosensors, and optogenetic tools engineered from phytochromes. Chem Rev 117
(9):6423–6446
6. Hong G, Antaris AL, Dai H (2017) Near-infrared fluorophores for biomedical imaging.
Nat Biomed Eng 1:0010
7. Sordillo LA, Pu Y, Pratavieira S, Budansky Y, Alfano RR (2014) Deep optical imaging of
tissue using the second and third near-infrared spectral windows. J Biomed Opt 19(5):056004
8. Antaris AL, Chen H, Cheng K, Sun Y, Hong G, Qu C, Diao S, Deng Z, Hu X, Zhang B et al
(2015) A small-molecule dye for NIR-II imaging. Nat Mater 15(2):235–242
9. Carr JA, Franke D, Caram JR, Perkinson CF, Saif M, Askoxylakis V, Datta M, Fukumura D,
Jain RK, Bawendi MG et al (2018) Shortwave infrared fluorescence imaging with the clinically
approved near-infrared dye indocyanine green. Proc Natl Acad Sci 115(17):4465–4470
118
S. He and Z. Cheng