ACRYLIC MICROSPHERES INVIVO .1. DISTRIBUTION AND ELIMINATION OF POLYACRYLAMIDE MICROPARTICLES AFTER INTRAVENOUS AND INTRA-PERITONEAL INJECTION IN MOUSE AND RAT

  • 1 January 1979
    • journal article
    • research article
    • Vol. 211  (3) , 656-662
Abstract
Microspheres of 14C-labeled highly cross-linked polyacrylamide (mean diameter 0.25-0.30 .mu.m) were prepared by emulsion polymerization. The label was introduced in the polymer via the cross-linking monomer, N,N''-[14C]methylenebisacrylamide. The microparticles were used to follow qualitatively and quantitatively the distribution and the fate of polyacrylamide in mouse and rat after i.v. and i.p. injection. The polyacrylamide particles are rapidly cleared from the circulation (t1/2 [half-life] in rat .apprx. 40 min) by macrophages of the RES. They are mainly (.apprx. 80%) found in the liver and spleen both after i.v. and i.p. injection (4.1 mg given totally to mice weighing 20-25 g). They can also be detected early (1 h after i.v. injection) in the bone marrow, and particle aggregates are also initially found in the lungs, although no respiratory problems were noted. After .apprx. 16 wk, the radioactivity rapidly decreases in the liver and spleen, with t1/2 10-14 wk and 15-24 wk, respectively, depending on the route of administration. Radioactivity in the gut and gut walls detected 2 mo. after injection suggests that the polyacrylamide is slowly metabolized. No toxic effects, apart from transient hepatosplenomegaly, were detected in mice 45 wk after they were given 9.8 mg of polyacrylamide.