Long-circulating liposomes have been widely used to enhance efficacy of gene therapy. Antisense therapy might increase the efficacy of radiation or chemotherapy; therefore, we undertook to optimize the composition of the liposomal delivery vehicles. The radiolabeling efficiency, radiochemistry purity, and specific radioactivity of radioiodinated antisense oligonucleotides (ASON) were 71.66 ± 7.73, 98.33 ± 0.39%, 4.09 ± 0.11 MBq/nmol. Radioiodinated ASON remained stable in 0.01 M HEPES buffer and human serum even after incubation for 4 hours. Mean diameter of the anionic long-circulating liposomes (ALCL) was 504 ± 31.76 nm with a polydispersity index (PDI) of 0.107 ± 0.008 before extrusion, 115 ± 8.5 nm with a PDI of 0.103 ± 0.002 after extrusion. The zeta potential of ALCL was −29.23 ± 0.45 mV. ALCL prepared for this study provided 70.28 ± 1.84% encapsulation efficiency. Compared with other liposome formulations, the ALCL mediated enhanced cellular uptake (32.51 ± 1.44%) by MCF-7 breast cancer cells (p<0.05).
Practical applications: Drug delivery systems can in principle provide enhanced efficacy and/or reduced toxicity for anticancer agents. LCL have become a commonly used carrier for gene therapy recently. ALCL are promising for the mediated radiation and antisense therapy for breast cancer which is the leading cause for women.