Large scale preparation of midkine antisense oligonucleotides nanoliposomes by a cross-flow injection technique combined with ultrafiltration and high-pressure extrusion procedures.

The midkine antisense oligonucleotide (MK-ASODN, 5'-CCC CGG GCC GCC CTT CTT CA-3') nanoliposomes have been identified to suppress hepatocellular carcinoma (HCC) growth effectively, and have a great potential to be an effective target drug for HCC. In this study, a facile and reproducible method for large-scale preparation of MK-ASODN nanoliposomes followed by lyophilization has been developed successfully. Meanwhile, the MK-ASODN nanoliposomes characteristics, storage stability and their antitumor efficiency were studied. The mean particle size of MK-ASODN nanoliposomes were 229.43±15.11 nm, and the zeta potential were 29.7±1.1 mV. High entrapment efficiency values were achieved around 90%. Transmission electron microscopy images revealed spherical shaped nanoliposomes. Nanoliposomes allowed sustained MK-ASODN release for as long as 14 days. During 180 days of storage, freeze-dried nanoliposomes showed no significant change in the mean size, zeta potential, entrapment efficiency and drug release ratio. Regarding their antitumor efficiency, the in vitro proliferation of human liver cancer cells were significantly inhibited by the MK-ASODN nanoliposomes. Furthermore, the MK-ASOND nanoliposomes also significantly inhibited the growth of HCC in the mouse model. In summary, the results confirmed that this large-scale preparation of MK-ASOND nanoliposomes was facile and reproducible, and potentially, could speed up the application process of our MK-ASOND nanoliposomes for HCC therapy.