in vivo targeting of colloidal carriers by novel graft copolymers

One of the major obstacles to the targeted delivery of colloidal carriers (nanocapsules) is the body's own defence mechanism in capturing foreign particles by the reticuloendothelial system (RES). This means that following intravenous administration, practically all nanometer size particles are captured by the RES (mainly the liver). This paper draws attention to a recent initiative on the design of 'macromolecular homing devices' which seem to disguise nanoparticles from the RES, and hence are of potential interest for the targeted delivery of nanocapsular carriers. The idea is based on a graft copolymer model embodying a link site for attachment (binding) to the carrier, a floating pad for maintaining the particles afloat in the blood stream, an affinity ligand for site-specific delivery and a structural tune for balancing the overall structure of the homing device. A general synthetic scheme for the preparation of such graft copolymers is given, and preliminary biological evaluations relating to the floating pad concept are discussed.

Radiopharmaceuticals for spleen and bone marrow studies

The spleen and bone marrow have important hematologic functions. Evaluation of bone marrow alone may be incomplete, unless the function of the spleen is studied also. In addition to hematologic functions, each organ has unique characteristics that may need to be evaluated in assessing its activity. The evaluation of the distribution of reticuloendothelial cells, through the phagocytosis of radioactive particles, provides the basis for most of the morphological and functional studies of these organs. During the past three decades, a variety of radioactive agents have been prepared and examined. Among them, colloids of 99mTc, heat-damaged 99mTc labeled RBCs, and the radionuclides of iron and indium, make possible the functional and morphological examination of the spleen and bone marrow by external scintigraphy.

Primary Liver Cell Carcinoma 24 Years after Intravenous Injection of Thorotrast

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