Method of imaging low density lipoproteins by atomic force microscopy

Area of Science:

• Biophysics
• Nanotechnology
• Biochemistry

Background:

• Low-density lipoproteins (LDL) are crucial in lipid metabolism and cardiovascular disease.
• Accurate structural characterization of LDL is essential for understanding its function and pathology.
• Existing imaging techniques may require sample preparation that can alter LDL structure.

Purpose of the Study:

• To develop and report a simple method for imaging native low-density lipoproteins (LDL) using atomic force microscopy (AFM).
• To determine the dimensions and structural characteristics of individual LDL particles.
• To highlight the advantages of AFM for biological sample analysis in liquid environments.

Main Methods:

• Utilized Atomic Force Microscopy (AFM) for imaging biological samples in an aqueous environment.
• Employed AFM without requiring sample fixation or staining, preserving native LDL structure.
• Performed quantitative analysis of AFM data to measure particle dimensions.

Main Results:

• Successfully imaged individual low-density lipoprotein (LDL) particles using AFM.
• Measured the average diameter of LDL particles to be 23 +/- 3 nm.
• Determined the average height of LDL particles to be 10 +/- 2 nm, indicating an oblate spheroid structure.

Conclusions:

• AFM provides a valuable, non-invasive method for characterizing LDL structure and dimensions in their native state.
• The quasi-spherical shape on the xy-plane and oblate spheroid shape in the z-axis were confirmed.
• This technique facilitates further research into LDL morphology and its implications in health and disease.