The polyoxyethylene/polyoxypropylene block co-polymer Poloxamer-407 selectively redirects intravenously injected microspheres to sinusoidal endothelial cells of rabbit bone marrow

Christopher J H Porter, S. Moein Moghimi, Lisbeth Illum, Stanley S. Davis

Research output: Contribution to journalArticleResearchpeer-review

160 Citations (Scopus)


Small colloidal particulates (150 nm and below, in diameter) can be redirected specifically to the rabbit bone marrow following intravenous administration by coating their surface with the block co-polymer poloxamer-407, a non-ionic surfactant. The coated colloids are sequestered by the sinusoidal endothelial cells of the bone marrow and are accumulated in dense bodies within these cells. The uptake of poloxamer-4O7-coated colloids by marrow eondothelial cells suggests that the steric repulsive barrier, imposed by the polyoxyethylene segment of the polymer, to particle-cell interaction can apparently be overcome by a specific interaction mechanism(s) with the cell surface. Such a dramatic uptake cannot be achieved with other block co-polymers of similar structure to poloxamer-407. The application of the current model for the site-specific targeting or drug carriers to bone marrow and the prevention of the adherence of metastases of tumours which selectively colonize the bone marrow endothelium is discussed.

Original languageEnglish
Pages (from-to)62-66
Number of pages5
JournalFEBS Letters
Issue number1
Publication statusPublished - 22 Jun 1992
Externally publishedYes


  • Bone marrow
  • Endothelial cell
  • Microsphere
  • Poloxamer-4O7
  • Rabbit

Cite this