Heating tumors with tumor cell-derived nanoparticles to enhance chemoimmunotherapy for colorectal cancer

Aim: To investigate the mechanism of doxorubicin (DOX)-induced immunogenic cell death (ICD) and to improve immunotherapy efficacy. Materials & methods: In this study, hybrid vesicles containing DOX (HV-DOX) were prepared by thin-film hydration with extrusion, and the formulated nanoparticles were characterized physically. Furthermore, in vitro experiments and animal models were used to investigate the efficacy and new mechanisms of chemotherapy combined with immunotherapy. Results: DOX improved tumor immunogenicity by alkalinizing lysosomes, inhibiting tumor cell autophagy and inducing ICD. HVs could activate dendritic cell maturation, synergistically enhancing chemotherapeutic immunity. Conclusion: The mechanism of DOX-induced ICD was explored, and antitumor immunity was synergistically activated by HV-DOX to improve chemotherapeutic drug loading and provide relevant antigenic information.

Preparation of Neogambogic Acid Nanoliposomes and its Pharmacokinetics in Rats

OBJECTIVE

To prepare neogambogic acid nanoliposomes (GNA-NLC) and study its pharmacokinetics (PK) in rats.

STUDY DESIGN

An experimental study.

PLACE AND DURATION OF STUDY

Mudanjiang Medical University, Mudanjiang, China, from January 2016 to October 2017.

METHODOLOGY

GNA-NLC was prepared by emulsion evaporation-low temperature solidification. The entrapment efficiency, average particle size, and zeta potential were investigated. Male Wistar rats were injected with 1 mg/mL gambogic acid and GNA-NLC into the caudal vein respectively, and the plasma concentration was determined by UPLC- MS/MS. The pharmacokinetic parameters of the two agents were compared.

RESULTS

GNA-NLC prepared in this study were mostly spherical spheroids with an average particle size of 146.35 ±1.72 nm, polydispersity coefficient of 0.26 ±0.02, zeta potential of -28.24 ±0.13 MV, entrapment efficiency of 84.63%, and drug loading capacity of 4.23%. DSC showed that neogambogic acid nanoparticles had formed and neogambogic acid was amorphous in the matrix. The pharmacokinetics results in rats showed that GNA-NLC plasma concentration was significantly higher than that of common preparation of gambogic acid, with a half-life period of 10.14 ±0.03 hours, 4.57 times that of gambogic acid. AUC0 ~ 24h of gambogic acid in GNA-NLC lipidosome was 58.36 ±0.23 μg/h/mL, 4.83 times that of gambogic acid.

CONCLUSION

GNA-NLC can be prepared successfully by emulsion evaporation-low temperature solidification. The method is simple and easy to control. The GNA-NLC has a long cycle, and high blood concentration, sustained release compared with the raw material gambogic acid.