In vitro evaluation of nanoparticles spleen capture.
After intravenous injection, the main part of nanoparticles trapped by the spleen are concentrated in the marginal zone. The first step of this capture is the adhesion of the particles to the marginal zone macrophages. As classical techniques of cell suspension preparation did not allow to isolate without damage these actively capturing cells, tightly bound to a well-developed reticular meshwork, we designed a tissue slice incubation method, in order to study in vitro the interaction of nanoparticles with these particular macrophages, in conditions close to in vivo. In a serum supplemented medium, this in vitro model was able to give similar uptake profile than after intravenous injection of nanoparticles thus proving its validity. Surprisingly, no significant decrease of nanoparticles capture was observed when the medium was depleted from complement, immunoglobulins or proteins affine for heparin, while substitution of serum by purified albumin allowed a near optimal uptake. Addition of competitive ligands for lectin-like receptors did not show any clear inhibition of spleen capture. On the other hand, the scavenger receptor blocking agents, such as maleylated albumin or polyinosinic acid, induced a strong reduction of the spleen nanoparticles uptake. Thus, this paper proposes an in vitro binding assay as a reliable method to investigate the spleen capture of a large variety of nanoparticulate drug carriers. It is also a useful methodology to highlight the interactions between spleen cells and nanoparticles. The data obtained suggest that capture of nanoparticles depends on a multifactorial and complex phenomenon involving for a part albumin and the scavenger receptor.
Demoy
M
M
Laboratoire de Physico-Chimie, Pharmacotechnie et Biopharmacie, URA CNRS 1218, Faculté de Pharmacie, Université Paris XI, Châtenay-Malabry, France.
Andreux
J P
JP
Weingarten
C
C
Gouritin
B
B
Guilloux
V
V
Couvreur
P
P
D000818:Animals; D001798:Blood Proteins / Q000378:metabolism*; D002448:Cell Adhesion; D003470:Culture Media; D008264:Macrophages / Q000502:physiology; D008565:Membrane Proteins; D051379:Mice; D009924:Organ Culture Techniques; D010316:Particle Size; D011137:Polystyrenes; D011971:Receptors, Immunologic / Q000378:metabolism; D018110:Receptors, Lipoprotein; D051116:Receptors, Scavenger; D051122:Scavenger Receptors, Class B; D012710:Serum Albumin, Bovine / Q000378:metabolism; D013154:Spleen / Q000166:cytology* / Q000378:metabolism*
D001798:Blood Proteins; D003470:Culture Media; D008565:Membrane Proteins; D011137:Polystyrenes; D011971:Receptors, Immunologic; D018110:Receptors, Lipoprotein; D051116:Receptors, Scavenger; C454739:Scarb1 protein, mouse; D051122:Scavenger Receptors, Class B; D012710:Serum Albumin, Bovine