Liposomes Containing Clodronate Attenuate Spleen Injury in the Rat Model with Severe Acute Pancreatitis

Abstract

Background: Clodronate containing liposomes selectively deplete macrophages and Super Paramagnetic Iron Oxide (SPIO) nanoparticles facilitate cell labeling. In this research, we explored the protective role of clodronate-SPIO nanoparticle-liposomes in the rat model with Severe Acute Pancreatitis (SAP). Methods: SPIO nanoparticles were synthesized by facile thermal decomposition method. SPIO and clodronate-SPIO nanoparticles containing liposomes were made by the process of the film method. The models of SAP were made using rat pancreatic subcapsular injection of sodium taurocholate. For the SAP model, rats were slowly injected with SPIO nanoparticle-containing liposomes via the tail vein (the P group). Alternatively, rats in the T and C groups were injected with clodronate-SPIO nanoparticles-containing liposomes and saline, respectively, in a volume of 2 mL/kg body weight. Serum Amylase (SAM), Interleukin (IL)-6, and Tumor Necrosis Factor (TNF)-α were analyzed by ELISA. Pathological alterations in the pancreas and spleen were detected by Hematoxylin and Eosin (HE) staining, and apoptosis was detected with TUNEL staining. Spleen injury was evaluated after exposure to either SPIO nanoparticle-containing liposomes or clodronate-SPIO nanoparticle-containing liposomes. Results: Pathological alterations in the pancreas and spleen of SAP model rats administered clodronate-SPIO nanoparticlecontaining liposomes were slighter than those in SAP model rats administered SPIO-containing liposomes. The levels of serum amylase, IL-6, and TNF-α in SAP model rats administered SPIO nanoparticle-containing liposomes were higher than those in the C group, but were significantly lower in SAP model rats administered SPIO nanoparticle-containing liposomes than those in rats administered clodronate-SPIO nanoparticle-containing liposomes (p < 0.01). In spleens, the rate of apoptosis was higher in rats administered clodronate-SPIO nanoparticle-containing liposomes than in those administered SPIO nanoparticle-containing liposomes at 2 and 6 h. Conclusions: Clodronate-containing liposomes protected against spleen injury in SAP rats, and SPIO nanoparticles could be used as a tracer for examination to detect spleen injury in SAP rats.