Recent Developments and Limitations of Poloxamine-Coated Long-Circulating Particles in Experimental Drug Delivery
There has been growing interest in the engineering of colloidal carrier systems that upon intravenous administration avoid rapid recognition by scavenger cells of the reticuloendothelial system and adequately remain in the blood. There are several reasons as to why the search for such ‘phagocyte-resistant’ or long-circulating particles is so extensive. First, long-circulating drug carriers may act as a’ sustained release system’ in the blood and slowly discharge their entrapped materials for better treatment and diagnosis. Secondly, long-circulating drug carriers may passively accumulate in pathological sites with affected vasculature (e.g., selected tumours, rheumatoid arthritis, infections) and improve or enhance treatment or diagnosis in those areas (Bakker-Woudenberg et al., 1993; Wu et al., 1993; Huang et al., 1994; Yuan et al., 1994). Thirdly, grafting or covalent attachment of homing molecules such as antibodies, peptides that mimic ligands for αvβ3 and αvβ5 integrins, oligosaccharides that mimic ligands for P-selectin (e.g., synthetic sialyl-Lewis X and small heparin chains containing four or more monosaccharide residues), folate, etc. to long-circulating carries can dramatically improve the targeting precision to sites beyond the reticuloendothelial system (e.g., vascular and tumour endothelial cells, circulating blood cells, circulating toxic materials) (Mulligan et al., 1993; Nelson et al., 1993; Lee and Low, 1994; Bloemen et al., 1995; Gabizon, 1995; Moghimi, 1995a, c; Torchilin, 1995; Lee and Huang, 1996; Huang et al., 1997; Pasqualini et al., 1997).
KeywordsKupffer Cell Latex Bead Polystyrene Bead Polyoxyethylene Ether Sustained Release System
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- Geyer, R.P., 1967, Studies on the metabolism of intravenous fat emulsions, Fette Med 6:59.Google Scholar
- Mayer D.C., Strada S.J., Hoff, C, Hunter, R.L., and Artmann, M., 1994, Effects of poloxamer 188 in a rabbit model of hemorrhagic shock, Annal Clin Lab Sci 24: 302.Google Scholar
- Moghimi, S.M., 1997, Prolonging the circulation time and modifying the body distribution of intravenously injected polystyrene nanospheres by prior intravenous administration of poloxamine-908. A reticuloendothelial blockade event or manipulation of nanosphere surface in vivo?, Biochim Biophys Acta 1336:1.PubMedCrossRefGoogle Scholar
- Moghimi, S.M., and Gray, T.A., 1997, A single dose of intravenously injected poloxamine-coated long-circulating particles triggers macrophage clearance of subsequent doses in rats, Clin Science 93:371.Google Scholar
- Moghimi, S.M., Hedeman, H., Ilium, L., and Davis, S.S. 1993b, Effect of splenic congestion associated with haemolytic anaemia on filtration of’ spleen-homing’ microspheres, Clin Science 84: 605.Google Scholar
- Moghimi, S.M., and Patel, H.M., 1998, Serum-mediated recognition of liposomes by phagocytes of the reticuloendothelial system — The concept of tissue specificity, Adv Drug Deliv Rev (in press).Google Scholar
- Naper, D.H., 1983, Polymeric Stabilization of Colloidal Dispersions, Academic Press, New York.Google Scholar
- Schmolka, I.R., 1977, A review of block polymer surfactants, J Am Chem Soc 54: 110.Google Scholar