Cationic liposomes loaded with doxorubicin targeting to the tumor neovasculature in vitro / 药学学报

This study was conducted to investigate the in vitro characteristics of cationic liposomes composed of 3beta-[N-[2-(N', N'-dimethylamino) ethyl] carbamoyl] cholesterol (DC-Chol) and dipalmitoylphosphatidylcholine loaded with doxorubicin (DXR), and to provide useful information for the in vivo tumor vascular targeting of cationic liposomes. Cationic liposomes composed of different amounts of DC-Chol (0 mol%, 10 mol%, 25 mol%, 50 mol%) were loaded with the conventional anti-cancer drug doxorubicin. Their size, zeta potential, encapsulation efficiency, and DXR release in vitro were investigated. Moreover, their uptake by rat aortic endothelial cells (RAECs) was observed at 15 min, 30 min, 1 h, and 4 h of incubation. FITC-Dextran was i.v. injected to the H22 tumor-bearing KM mice to stain the neovasculature. The characteristics of resulting DXR-loaded cationic liposomes were in stable characteristics with particle sizes around 100 - 200 nm and capsulation efficiency greater than 90%. Increased cationic lipid led to enhanced zeta potential, and meanwhile it also resulted in quick release of the loaded drug, indicating increased slits or pores on the membrane upon the addition of DC-Chol. RAECs could more avidly take up DXR-loaded cationic liposomes when the content of DC-Chol increased in the liposomes, and DXR were quickly released in the cytoplasm and transported to the nuclei. The neovasculature stained by FITC-Dextran was clearly observed. DXR-cationic liposomes composed of DC-Chol could be used for tumor vascular targeting in vivo for further study.

Advancement in the methods for gene dosage analysis / 中华医学遗传学杂志

Gene dosage determination is increasingly important for the study of both genome variation and rearrangement associated with complex diseases. Large genomic duplications and deletions are increasingly found as the causes. Methods such as PCR or sequencing are usually qualitative rather than quantitative. Thus, these methods can not detect large genomic duplications or deletions. Therefore, searching for a gene dosage method which is reliable, sensitive and high-throughput becomes imperative. Many high-performance technologies have been developed for gene dosage analyses in the recent years. There are generally three categories of methods including cytogenetic, Southern or dot blotting, or PCR amplification. Recent development in these techniques have been introduced and discussed in this review, which will help people to choose a suitable method for different research.