Ae. Hawley et al., LYMPH-NODE LOCALIZATION OF BIODEGRADABLE NANOSPHERES SURFACE-MODIFIEDWITH POLOXAMER AND POLOXAMINE BLOCK-COPOLYMERS, FEBS letters, 400(3), 1997, pp. 319-323
Studies were performed to develop a sub-100 nm biodegradable colloidal
system for the efficient delivery of drugs and diagnostic agents to t
he lymphatic system. Nanospheres of poly(lactide-co-glycolide) were pr
epared by interfacial polymer deposition. The nanospheres were coated
with block co-polymers in order to modify their surface characteristic
s. Radiolabelling of the nanospheres for in vivo tracing was achieved
by the incorporation of the lipophilic complex In-111-oxine during nan
osphere preparation. In vitro stability of the radiolabelled nanospher
es was determined in rat serum at 37 degrees C. The lymphatic distribu
tion of the nanospheres was determined after subcutaneous administrati
on to the rat. Lymphatic uptake of all coated systems was enhanced com
pared to the uncoated nanospheres, and a maximal uptake of 17% of the
administered dose in the regional lymph nodes was achieved. These obse
rvations suggest that the nanospheres are suitable for diagnostic and
therapeutic applications in clinical and experimental medicine.