Study On Establishment And Evaluation In Vitro Of CPT-11-loaded Nanoparticles/red Blood Cells Complex

Background:Irinotecan is a common chemotherapy drug and is commonly used in standard chemotherapy after failure of first-line treatment of metastatic colorectal cancer. It has been widely used in the treatment of colorectal cancer, gastric cancer, pancreatic cancer, lung cancer and genital system tumor. Adverse reactions of irinotecan often include a lack of appetite, nausea, vomiting, diarrhea, white blood cells and neutropenia, anemia, thrombocytopenia, hair loss and Acetylcholine syndrome, etc., which limits its clinical application. Nanoparticles (NPs) are actively explored for encapsulation and targeted delivery of drugs. However, suffer from the limitation of rapid clearance by the mononuclear phagocytic system (MPS) located primarily in the liver and spleen, thereby limitingthe dose available for the disease site. on the other hand, red blood cells with a favorable circulation profile may be used as "natural carriers" improving the NP pharmacokinetics. Coupling of NPs to RBCs has the potential to dramatically alter NP behavior in circulation, which improve the current treatment strategies for cancer.Objectives:To prepare a irinotecan carried system by PLGA nano-sphere, a material with biodegradability, sustained release and targeted capability, which is attached to the surface of red blood cells to prolong circulation of NPs.Methord:The irinotecan-PLGA nanoparticles were prepared by double emulsif ication solvent evaporation technique. The particle size distribution of nanoparticles is determined by laser particle size analyzer. The drug loading, encapsulation efficiency of irinotecan and release in vitro were detected by ultraviolet spectrophotometer. A known number of nanoparticles were incubated with red blood cells at room temperature for 30min. Particle attachment to RBC was mediated by electrostatic and hydrophobi.c interactions. A FACS Aria II Flow Cytometer was used to quantify attachment of nanoparticles to red blood cells. Cell proliferation inhibition was measured by MTT to compare the cytotoxicity of nanoparticle/RBCs complex to SW480. Experiment of phagocyte compare the phagocytosis of nanoparticles and nanoparticles/RBCs complex.Results:The average-diameter of irinotecan-PLGA-NPs was 299.7nm, drug loading and encapsulation efficiency were 0.95% and 60.22%, respectively. The cumulative release of irinotecan was 59.62% at the 120h. The number of adherent particles increased with increasing particle-RBC ratios, irinotecan nanoparticles appeared better cell proliferation inhibition than free irinotecan and nanoparticles/RBCs complex showed less cell proliferation inhibition than free irinotecan or irinotecan nanoparticles. The cytotoxicity of all three groups was increased with time.Conclusion:1.The nanoparticles prepared in this research are stable and have sustained release behavior.2.The cytotoxicity of irinotecan NPs/RBCs complex and irinotecan nanoparticles was increased with time longer.Coupling nanoparticles to red blood cells can reduce rapid clearance by the mononuclear phagocytic system (MPS) located primarily in the liver and spleen, which increases NPs circulation time.