Additional Funding Sources

The project described was supported by the Center of Excellence in Biomedical Research through the Institutional Development Award (IDeA) from the National Institute of General Medical Sciences of the National Institutes of Health under Grant Nos. P20GM109095 and P20GM103408 and the National Science Foundation S-STEM Gateway Scholarships in Biological Sciences under Grant No. DUE-1644233. Additional support was received from National Science Foundation CAREER Grant No. 1551146.

Abstract

Adverse drug effects from chemotherapeutic agents are a well-known deterrent and a potential limiting factor for appropriate treatment regimens of tumors. To circumvent these limitations several approaches for precision chemotherapy have been proposed. Among those, liposomes are the most advanced carriers for drugs to tumor sites. Liposomes are spherical lipid structures that mimic the cell membrane, and their ability to protect and transport biologically active molecule is exploited for the purpose of targeted drug delivery. In this respect, our work describes production and characterization of liposomes via extrusion.

We produced liposomes from mixtures of lipids that included Polyethylene glycol (PEG) to evade the immune system of the host. They were actively loaded with a drug simulator (i.e., Acridine Orange, AO) using a pH gradient. The liposomes were characterized by microscopy and dynamic light scattering for size distribution. The liposomes with the drug simulator were verified by fluorescence spectroscopy and exploitation of self-quenching of AO at high concentration. Our results show that the liposomes produced by extrusion are uniform, PEG addition prevents aggregation, and the pH gradient approach attains large concentration of the loaded molecules.

Share

COinS
 

Preparation of Loaded Liposomes by Extrusion and Methods of Characterization

Adverse drug effects from chemotherapeutic agents are a well-known deterrent and a potential limiting factor for appropriate treatment regimens of tumors. To circumvent these limitations several approaches for precision chemotherapy have been proposed. Among those, liposomes are the most advanced carriers for drugs to tumor sites. Liposomes are spherical lipid structures that mimic the cell membrane, and their ability to protect and transport biologically active molecule is exploited for the purpose of targeted drug delivery. In this respect, our work describes production and characterization of liposomes via extrusion.

We produced liposomes from mixtures of lipids that included Polyethylene glycol (PEG) to evade the immune system of the host. They were actively loaded with a drug simulator (i.e., Acridine Orange, AO) using a pH gradient. The liposomes were characterized by microscopy and dynamic light scattering for size distribution. The liposomes with the drug simulator were verified by fluorescence spectroscopy and exploitation of self-quenching of AO at high concentration. Our results show that the liposomes produced by extrusion are uniform, PEG addition prevents aggregation, and the pH gradient approach attains large concentration of the loaded molecules.

 

To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.