Selective targeting of magnetic albumin microspheres to the Yoshida sarcoma: Ultrastructural evaluation of microsphere disposition
Magnetic albumin microspheres (1 μ m average diameter) were selectively targeted to subcutaneous solid Yoshida sarcoma tumors (average size 450 mm 2) in Holtzman rats. This was accomplished by placing an external magnet adjacent to the tumor while the microspheres were infused. Microspheres containe...
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Published in | European journal of cancer & clinical oncology Vol. 19; no. 1; pp. 141 - 147 |
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Main Authors | , , , , , |
Format | Journal Article |
Language | English |
Published |
England
Elsevier Ltd
1983
|
Subjects | |
Online Access | Get full text |
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Summary: | Magnetic albumin microspheres (1 μ
m average diameter) were selectively targeted to subcutaneous solid Yoshida sarcoma tumors (average size 450
mm
2) in Holtzman rats. This was accomplished by placing an external magnet adjacent to the tumor while the microspheres were infused. Microspheres contained ultra-fine particles of
Fe
3O
4
and no drug (placebo). Placebo microspheres were used due to the previously demonstrated rapid tumoricidal effect of targeted low-dose doxorubicin microspheres. Animals were killed 10
min, 60
min, 30
min, 24
hr and 72
hr after microsphere administration and tumors were examined by transmission electron microscopy to determine the
in vivo disposition of the magnetically targeted microspheres. Using placebo microspheres, we have demonstrated microspheres endocytosed in endothelial cells as early as 10
min after infusion. By 30
min microspheres can be seen in the extravascular compartment, sitting adjacent to tumor cells and occasionally in tumor cells. By 24
hr the majority of microspheres have been endocytosed by tumor cells. Microspheres were still observed within tumor cells as late as 72
hr after administration. The rapid extravasation and cellular uptake of magnetically focused microspheres explains the extremely rapid tumoricidal effect previously observed when doxorubicin-containing microspheres were targeted to the tumor. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0277-5379 |
DOI: | 10.1016/0277-5379(83)90409-1 |