Scanning and transmission electron microscopy of biodegradable microspheres (DSM) in blood vessels.
A type of biodegradable microsphere (DSM), approximately 45 microns in diameter, made of polymerized potato starch (Pharmacia, Sweden) was intravenously injected into rats to observe the state of DSM in small blood vessels in the kidney and liver at the electron microscopic level. Prior to their digestion with amylase, individual DSM changed their round shape to an irregularly folded one to occupy almost the whole area of the lumen. At the transmission electron microscopic level, DSM were impregnated with colloidal iron and were easily identified. Interaction of the iron labelled DSM with the surface of endothelial cells was unexpectedly loose and no adherence or fusion of this surface was observed. The starch substance was not visible in the pinocytotic vesicles of the endothelium. These findings suggest the independent profile of DSM in situ.
Department of Veterinary Anatomy, Yamaguchi University, Japan.
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T
Makita
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H
Ichimal
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S
Kagabu
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K
Manba
I
I
Naito
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R
Lindblom
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M
Hatsuoka
T
T
Okawa
D000818:Animals; D001673:Biodegradation, Environmental; D001808:Blood Vessels / Q000648:ultrastructure*; D002214:Capsules; D008854:Microscopy, Electron; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D051381:Rats; D013213:Starch / Q000378:metabolism
D002214:Capsules; D013213:Starch