Peptide-Based Ligand for Active Delivery of Liposomal Doxorubicin

Doxorubicin (DOX) has been extensively used in the clinic to treat malignant tumors such as leukemias and Hodgkin’s lymphoma. However, the severe cardiotoxicity associated with the use of DOX requests the development of alternative and efficient pharmaceutical formulations. The PEGylated liposome of DOX can significantly reduce the cardiotoxicity but still lacks the active targeting towards cancer cells. Modification of liposomal DOX with active ligands would then be a rational approach to enhance the transportation of the toxin into tumor cells. Currently used targeting ligands include antibodies, proteins, small molecules, and peptides. By virtue of the advantages such as easy preparation, lower cost, and elevated resistance to enzymatic degradation, peptides are attracting a significant amount of interest as active targeting ligands for pharmaceutics. In this paper, we will briefly discuss the application of peptide ligands for the improvement of the therapeutic efficacy of liposomal DOX.

Growth behavior of gold nanoparticles synthesized in unsaturated fatty acids by vacuum evaporation methods

Physical vapor evaporation of metals on low vapor pressure liquids is a simple and clean method to synthesize nanoparticles and thin films, though only little work has been conducted so far. Here, gold nanoparticles were synthesized by vacuum evaporation (VE) methods in ricinoleic acid and oleic acid, two typical unsaturated fatty acids (UFAs). The two solvents formed black aggregates after deposition and then shrunk and finally disappeared with the progress of time. By transmission electron microscopy (TEM) images, nanoparticles in ricinoleic acids formed aggregates and then dispersed by time, while in oleic acid big aggregates were not observed in all timescales. From TEM images and small angle X-ray scattering (SAXS) measurements, the mean size of the nanoparticles was about 4 nm in both ricinoleic and oleic acids. UV-Vis spectra were also taken as a function of time and the results were consistent with the growth behavior presumed by TEM images. Air exposure had an influence on the behavior of the sample triggering the nanoparticle formation in both solvents. From control experiments, we discovered that oxygen gas triggered the phenomenon and nanoparticles function as a catalyst for the oxidation of the UFAs. It stimulates the phenomenon and in ricinoleic acid, specifically, electrons are transferred from riconleic acid to the gold nanoparticles, enhancing the surface potential of the nanoparticles and the repulsive force between their electronic double layers.