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Ultrastructural localization of intravenously injected carbon nanohorns in tumor.

Matsumura S, Yuge R, Sato S, Tomida A, Ichihashi T, Irie H, Iijima S, Shiba K, Yudasaka M - Int J Nanomedicine (2014)

Bottom Line: The CNHs in normal skin tissue were similarly observed.The extravasation of CNHs was not so obvious in tumor but was easily found in normal skin, which was probably due to their vessel wall structure difference.Proper understanding of the location of CNHs in tissues is helpful in the development of the medical uses of CNHs.

View Article: PubMed Central - PubMed

Affiliation: Cancer Institute, Japanese Foundation for Cancer Research, Tokyo, Japan.

ABSTRACT
Nanocarbons have many potential medical applications. Drug delivery, diagnostic imaging, and photohyperthermia therapy, especially in the treatment of tumors, have attracted interest. For the further advancement of these application studies, the microscopic localization of nanocarbons in tumor tissues and cells is a prerequisite. In this study, carbon nanohorns (CNHs) with sizes of about 100 nm were intravenously injected into mice having subcutaneously transplanted tumors, and the CNHs in tumor tissue were observed with optical and electron microscopy. In the tumor tissue, the CNHs were found in macrophages and endothelial cells within the blood vessels. Few CNHs were found in tumor cells or in the region away from blood vessels, suggesting that, under these study conditions, the enhanced permeability of tumor blood vessels was not effective for the movement of CNHs through the vessel walls. The CNHs in normal skin tissue were similarly observed. The extravasation of CNHs was not so obvious in tumor but was easily found in normal skin, which was probably due to their vessel wall structure difference. Proper understanding of the location of CNHs in tissues is helpful in the development of the medical uses of CNHs.

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Related in: MedlinePlus

Macrophage within a blood vessel in subcutaneously transplanted tumor tissue.Notes: Obtained 21 hours following CNH injection. STEM ZC images (A, B) and TEM images of phagosomes (C, D) located within a pseudopod. Stars indicate CNHs.Abbreviations: RBC, red blood cells; CNH, carbon nanohorn; STEM ZC, scanning transmission electron microscopy Z-contrast; TEM, transmission electron microscopy.
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f6-ijn-9-3499: Macrophage within a blood vessel in subcutaneously transplanted tumor tissue.Notes: Obtained 21 hours following CNH injection. STEM ZC images (A, B) and TEM images of phagosomes (C, D) located within a pseudopod. Stars indicate CNHs.Abbreviations: RBC, red blood cells; CNH, carbon nanohorn; STEM ZC, scanning transmission electron microscopy Z-contrast; TEM, transmission electron microscopy.

Mentions: To find the places where the CNHs existed in the tumor tissues more clearly, the tissues were precisely observed with electron microscopy. In the HRTEM observation, CNHs were identified with straight black lines of nanohorn tubule walls running within the CNH aggregates (Figure 1A) or by the black spots of Gd2O3 nanoparticles embedded inside the CNHs (Figure 1B). The CNHs were confirmed to exist within macrophages in tumor blood vessels (Figure 6A–D) and in vascular endothelial cells (Figure 7A–F). In the macrophages, CNHs were localized in membrane-delimited follicles (Figure 6A–D) that were most likely phagosomes (Figure 6C and D). CNHs were also found within micropinocytotic vesicles in endothelial cells (Figure 7C–F). Few CNHs were found outside of the blood vessels in the tumor tissue.


Ultrastructural localization of intravenously injected carbon nanohorns in tumor.

Matsumura S, Yuge R, Sato S, Tomida A, Ichihashi T, Irie H, Iijima S, Shiba K, Yudasaka M - Int J Nanomedicine (2014)

Macrophage within a blood vessel in subcutaneously transplanted tumor tissue.Notes: Obtained 21 hours following CNH injection. STEM ZC images (A, B) and TEM images of phagosomes (C, D) located within a pseudopod. Stars indicate CNHs.Abbreviations: RBC, red blood cells; CNH, carbon nanohorn; STEM ZC, scanning transmission electron microscopy Z-contrast; TEM, transmission electron microscopy.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4114911&req=5

f6-ijn-9-3499: Macrophage within a blood vessel in subcutaneously transplanted tumor tissue.Notes: Obtained 21 hours following CNH injection. STEM ZC images (A, B) and TEM images of phagosomes (C, D) located within a pseudopod. Stars indicate CNHs.Abbreviations: RBC, red blood cells; CNH, carbon nanohorn; STEM ZC, scanning transmission electron microscopy Z-contrast; TEM, transmission electron microscopy.
Mentions: To find the places where the CNHs existed in the tumor tissues more clearly, the tissues were precisely observed with electron microscopy. In the HRTEM observation, CNHs were identified with straight black lines of nanohorn tubule walls running within the CNH aggregates (Figure 1A) or by the black spots of Gd2O3 nanoparticles embedded inside the CNHs (Figure 1B). The CNHs were confirmed to exist within macrophages in tumor blood vessels (Figure 6A–D) and in vascular endothelial cells (Figure 7A–F). In the macrophages, CNHs were localized in membrane-delimited follicles (Figure 6A–D) that were most likely phagosomes (Figure 6C and D). CNHs were also found within micropinocytotic vesicles in endothelial cells (Figure 7C–F). Few CNHs were found outside of the blood vessels in the tumor tissue.

Bottom Line: The CNHs in normal skin tissue were similarly observed.The extravasation of CNHs was not so obvious in tumor but was easily found in normal skin, which was probably due to their vessel wall structure difference.Proper understanding of the location of CNHs in tissues is helpful in the development of the medical uses of CNHs.

View Article: PubMed Central - PubMed

Affiliation: Cancer Institute, Japanese Foundation for Cancer Research, Tokyo, Japan.

ABSTRACT
Nanocarbons have many potential medical applications. Drug delivery, diagnostic imaging, and photohyperthermia therapy, especially in the treatment of tumors, have attracted interest. For the further advancement of these application studies, the microscopic localization of nanocarbons in tumor tissues and cells is a prerequisite. In this study, carbon nanohorns (CNHs) with sizes of about 100 nm were intravenously injected into mice having subcutaneously transplanted tumors, and the CNHs in tumor tissue were observed with optical and electron microscopy. In the tumor tissue, the CNHs were found in macrophages and endothelial cells within the blood vessels. Few CNHs were found in tumor cells or in the region away from blood vessels, suggesting that, under these study conditions, the enhanced permeability of tumor blood vessels was not effective for the movement of CNHs through the vessel walls. The CNHs in normal skin tissue were similarly observed. The extravasation of CNHs was not so obvious in tumor but was easily found in normal skin, which was probably due to their vessel wall structure difference. Proper understanding of the location of CNHs in tissues is helpful in the development of the medical uses of CNHs.

Show MeSH
Related in: MedlinePlus