Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2021 Aug 25;6(35):22616-22624.
doi: 10.1021/acsomega.1c02632. eCollection 2021 Sep 7.

Optical-Property-Enhancing Novel Near-Infrared Active Niosome Nanoformulation for Deep-Tissue Bioimaging

Suman Bishnoi  1 , Sheeba Rehman  1 , Surjendu Bikash Dutta  1 , Soumya Kanti De  2 , Anjan Chakraborty  2 , Debasis Nayak  1 , Sharad Gupta  1   3
Affiliations

Optical-Property-Enhancing Novel Near-Infrared Active Niosome Nanoformulation for Deep-Tissue Bioimaging

Suman Bishnoi et al. ACS Omega. .

Abstract

Indocyanine green (ICG) is a clinically approved near-infrared (NIR) contrast agent used in medical diagnosis. However, ICG has not been used to its fullest for biomedical imaging applications due to its low fluorescence quantum yield, aqueous instability, concentration-dependent aggregation, and photo and thermal degradations, leading to quenching of its fluorescence emission. In the present study, a nanosized niosomal formulation, ICGNiosomes (ICGNios), is fabricated to encapsulate and protect ICG from degradation. Interestingly, compared to free ICG, the ICGNios exhibited higher fluorescence quantum yield and fluorescence emission with a bathochromic shift. Also, ICGNios nanoparticles are biocompatible, biodegradable, and readily uptaken by the cells. Furthermore, ICGNios show more enhanced fluorescence intensity through ∼1 cm thick chicken breast tissue compared to free ICG, which showed minimal emission through the same thickness of tissue. Our results suggest that ICGNios could offer a promising platform for deep-tissue NIR in vivo imaging to visualize inaccessible tissue microstructures for disease diagnosis and therapeutics.

PubMed Disclaimer

Conflict of interest statement

The authors declare no competing financial interest.

Figures

Figure 1
Figure 1
Schematic representation of the preparation of niosomes and ICGNios by the thin-film hydration method. Tween 80, Span 80, and cholesterol are dissolved in chloroform followed by the formation of a thin film by evaporating chloroform using rotary evaporation at 37 °C. Niosomes and ICGNios are fabricated by hydration of the thin film of nonionic surfactants using DI water and ICG dissolved in DI water.
Figure 2
Figure 2
Morphological characterization of niosomes and ICGNiosomes (ICGNios). (a) Scanning electron microscopy (SEM) image of niosomes, (b) SEM image of ICGNios, and (c) transmission electron microscopy (TEM) image of ICGNios. Scale bar is 200 nm. (d, e) Dynamic light scattering (DLS) measurement of niosomes and ICGNios depicting the hydrodynamic diameter (Dh) and the polydispersity index (PDI) of niosomes and ICGNios.
Figure 3
Figure 3
Biochemical characterizations of free indocyanine green (ICG), niosomes, and ICGNiosomes (ICGNios). (a) Absorption spectra of free ICG, niosomes, and ICGNios. (b) Fitted absorption spectrum of ICGNios with R2 = 99.86%. (c) Fitted absorption spectrum of free ICG with R2 = 99.43%. (d) Fluorescence emission spectra of free ICG, niosomes, and ICGNios (smoothed curves).
Figure 4
Figure 4
Photostability and storage stability of ICGNios vs free ICG. (a) Photostabilities (%) of ICGNios and free ICG under exposure of ambient light at room temperature. (b) Storage stabilities (%) of ICGNios and free ICG incubated at 4 °C in the dark condition.
Figure 5
Figure 5
Biocompatibility and NIR imaging of niosomes, ICGNios, and free ICG in HeLa cells. (a) MTT assay of niosomes and ICGNios, where PC is the positive control. (b) Fluorescence imaging of HeLa cells; the DAPI staining nuclei are shown in blue color, and ICG fluorescence emission is displayed in red color. Scale bar is 20 μm. (c) Mean fluorescence emission intensity plot of the control, free ICG, and ICGNios.
Figure 6
Figure 6
Ex vivo deep-tissue enhanced NIR imaging of chicken breast tissue of ICGNios vs free ICG. (a) Picture of capillary tubes filled with water, free ICG, and ICGNios placed over a chicken tissue sample with the thickness of ∼1 cm. (b) Bright-field and NIR bioimaging of CT filled with water, free ICG, and ICGNios (column 1 and 2) and chicken breast tissue with CT filled with water, free ICG, and ICGNios (columns 3 and 4). Scale bar is 100 μm. (c) Mean fluorescence intensity plot of chicken breast tissue placed beneath the CT filled with water, free ICG, and ICGNios.
See this image and copyright information in PMC

References

    1. Zhao Y.; Van Rooy I.; Hak S.; Fay F.; Tang J.; Davies C. D. L.; Skobe M.; Fisher E. A.; Radu A.; Fayad Z. A.; De Mello Donegá C.; Meijerink A.; Mulder W. J. M. Near-Infrared Fluorescence Energy Transfer Imaging of Nanoparticle Accumulation and Dissociation Kinetics in Tumor-Bearing Mice. ACS Nano 2013, 7, 10362–10370. 10.1021/nn404782p. - DOI - PMC - PubMed
    1. Smith A. M.; Mancini M. C.; Nie S. Bioimaging: Second Window for in Vivo Imaging. Nat. Nanotechnol. 2009, 4, 710–711. 10.1038/nnano.2009.326. - DOI - PMC - PubMed
    1. Hill T. K.; Abdulahad A.; Kelkar S. S.; Marini F. C.; Long T. E.; Provenzale J. M.; Mohs A. M. Indocyanine Green-Loaded Nanoparticles for Image-Guided Tumor Surgery. Bioconjugate Chem. 2015, 26, 294–303. 10.1021/bc5005679. - DOI - PMC - PubMed
    1. Zheng X.; Zhou F.; Wu B.; Chen W. R.; Xing D. Enhanced Tumor Treatment Using Biofunctional Indocyanine Green-Containing Nanostructure by Intratumoral or Intravenous Injection. Mol. Pharmaceutics 2012, 9, 514–522. 10.1021/mp200526m. - DOI - PMC - PubMed
    1. Yoneya S.; Saito T.; Komatsu Y.; Koyama I.; Takahashi K.; Duvoll-Young J. Binding Properties of Indocyanine Green in Human Blood. Invest. Ophthalmol. Visual Sci. 1998, 39, 1286–1290. - PubMed