Cholesteryl Ester-Rich Lipid Inclusions from Human Aortic Fatty Streak and Fibrous Plaque Lesions of Atherosclerosis II. Physical Properties of Swelling, Resiliency and Lyotropy as Liquid Crystal

The physical properties of the lipids accumulating as spherical inclusions in human atherosclerotic lesions were explored both in vivo and in vitro conditions. They were mostly anisotropic within the cytoplasma of cells and in an average diameter of 1.96 μ. When suspended in hydrophilic media, say of physiological saline solution, in 4 hours they swelled 2.4 times in volume and changed into isotropic form. They were resilient and deformable in three dimensional configuration, and lyotropic in polar media. When dried they underwent a phase shifting from liquid crystal to true solid crystal. These physical properties of lipid inclusions gained in a new significance for their role in metabolic deterioration of intima cells, rupture and necrosis of foam cells, and destruction of the intimal and medial architectures, which set on mesenchymal reactions leading eventually to thickening and hardening of the arteries.