title: Pharmacokinetic change of nanoparticulate formulation "Lactosome" on multiple administrations.
abstract: Lactosome, which is a polymer micelle composed of poly(lactic acid)-b-poly(sarcosine), was applied successfully for solid tumor imaging. Lactosome is considered to escape from the reticuloendothelial system recognition, and shows prolonged in vivo blood clearance time. In vivo disposition of Lactosome, however, changed upon multiple dosages. Lactosome at the 2nd dosage was cleared from the blood stream by trapping at liver. This accelerated blood clearance (ABC) phenomenon is explained by production of anti-Lactosome IgM and IgG(3) through the immune response related with B-lymphocyte cells. The memory effect of B-lymphocyte cells lasted nearly for six months in mouse. The epitope moiety of Lactosome is concluded to be poly(sarcosine) based on the competitive inhibition assay. Since the ABC phenomenon was also reported with PEGylated liposome, nanoparticles in general may be potential in triggering the immune system.
authors: Technology Research Laboratory, Shimadzu Corporation, Kyoto 619-0237, Japan.
authors: Eri
authors: E
authors: Hara
authors: Akira
authors: A
authors: Makino
authors: Kensuke
authors: K
authors: Kurihara
authors: Fumihiko
authors: F
authors: Yamamoto
authors: Eiichi
authors: E
authors: Ozeki
authors: Shunsaku
authors: S
authors: Kimura
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology; D003952:Diagnostic Imaging; D018985:Epitopes, B-Lymphocyte; D007074:Immunoglobulin G / Q000276:immunology; D007075:Immunoglobulin M / Q000276:immunology; D007156:Immunologic Memory; D008297:Male; D051379:Mice; D008823:Micelles; D053758:Nanoparticles / Q000008:administration & dosage*; D011091:Polyesters / Q000008:administration & dosage* / Q000493:pharmacokinetics
chemical_list: D018985:Epitopes, B-Lymphocyte; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D008823:Micelles; D011091:Polyesters; C578344:poly(lactic acid)-b-poly(sarcosine)