Evaluation of the effects of surface charge on cytotoxicity of liposomal Doxorubicin on bone cancer cell line (Osteosarcoma)

In the present study, PEGylated liposomal formulation containing doxorubicin was synthesized in order to study the effects of surface charge on its cytotoxicity.
Liposomal doxorubicin containing DPPC, cholesterol and phospholipid DSPE-mPEG with various amounts of cationic phospholipid, DOTAP, (0, 5.2 and 20%) was prepared by pH gradient method. Prepared nanoparticles were evaluated in term of percentage of drug loading, particle size, polydisparity index, 48-hour drug release, and surface charge. The cytotoxicity of free and entrapped doxorubicin on Saos-2 cell lines was also compared.
The percentages of drug loading for all three formulations were higher than 82 percent. All formulations were monodisperse. The particle size was reduced by increasing cationic properties of particles. The zeta-potential varied from -23 to 22.4, and 43% of the drug was released from the liposome during 48 hours. Cytotoxicity of doxorubicin increased with encapsulation. Addition of cationic phospholipid reduced cell survival.
Increasing cytotoxicity of doxorubicin loaded into cationic liposomes is due to the more sustained-release of the system and also the toxicity created by DOTAP in the structure. Cytotoxicity of doxorubicin improved by entrapping it into liposomal vesicles. Doxorubicin loaded into cationic liposome shows highest toxicity.