Journal
LIPIDS
Volume 46, Issue 5, Pages 469-477Publisher
SPRINGER HEIDELBERG
DOI: 10.1007/s11745-010-3493-1
Keywords
NALDI; MALDI; Mass spectrometry; Lipids; Quantitation; Drug delivery
Funding
- NIH, National Cancer Institute, Center for Cancer Research
- National Cancer Institute, National Institutes of Health [HHSN261200800001E]
Ask authors/readers for more resources
Since its introduction as an ionization technique in mass spectrometry, matrix-assisted laser desorption ionization (MALDI) has been applied to a wide range of applications. Quantitative small molecule analysis by MALDI, however, is limited due to the presence of intense signals from the matrix coupled with non-homogeneous surfaces. The surface used in nano-structured laser desorption ionization (NALDI) eliminates the need for a matrix and the resulting interferences, and allows for quantitative analysis of small molecules. This study was designed to analyze and quantitate phospholipid components of liposomes. Here we have developed an assay to quantitate the DPPC and DC8,9PC in liposomes by NALDI following various treatments. To test our method we chose to analyze a liposome system composed of DPPC (1,2-dipalmitoyl-sn-glycero-3-phosphocholine) and DC8,9PC (1,2-bis(tricosa-10,12-diynoyl)-sn-glycero-3-phosphocholine), as DC8,9PC is known to undergo cross-linking upon treatment with UV (254 nm) and this reaction converts the monomer into a polymer. First, calibration curves for pure lipids (DPPC and DC8,9PC) were created using DMPC (1,2-dimyristoyl-sn-glycero-3-phosphocholine) as an internal standard. The calibration curve for both DPPC and DC8,9PC showed an R-2 of 0.992, obtained using the intensity ratio of analyte and internal standard. Next, DPPC:DC8,9PC liposomes were treated with UV radiation (254 nm). Following this treatment, lipids were extracted from the liposomes and analyzed. The analysis of the lipids before and after UV exposure confirmed a decrease in the signal of DC8,9PC of about 90%. In contrast, there was no reduction in DPPC signal.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available