Microvortex-induced turbulent mixing for reconstitution of high-density lipoprotein-mimicking nanoparticles with aggregation-prone phosphatidylcholine.

Lipid nanoparticles often contain a phosphatidylcholine with a long chain fatty acid, 1,2-distearoyl--3-phosphocholine (DSPC). However, their preparation often encounters difficulties such as the inability to yield <20 nm nanoparticles due to the aggregation-prone behavior of DSPC. High-density lipoproteins (HDLs) are ∼10 nm protein-bound lipid nanoparticles in our body, and microfluidic preparations of HDL-mimicking nanoparticles (μHDL) have been reported.

Comprehensive Analysis of Drug Loading into Engineered Lipoprotein Nanoparticles toward Their Eye Drop Application.

The drug loading capacity of an engineered lipoprotein (eLP1) and the colloidal stability of drug-loaded eLP1s were assessed with 12 drugs with different charges/hydrophobicities. The capacity was largely correlated with their log P values, and the binding to the protein moiety was suggested for two drugs. The size of drug-loaded eLP1 formulations after freeze-drying followed by resolubilization hardly changed.

Effects of lipoprotein nanoparticles' composition and size on their internalization in plant and mammalian cells.

The internalization of engineered high-density lipoprotein nanoparticles (engineered lipoproteins [eLPs]) with different lipid and protein compositions, zeta potentials, and/or sizes were analyzed in representative plant and mammalian cells. The impact of the addition of a cell-penetrating peptide to eLPs on the internalization was very small in Bright Yellow (BY)-2 protoplasts compared with HeLa cells. When eLPs were prepared with one of the abundant lipids in BY-2 cells, digalactosyldiacylglycerol (DGDG) (eLP4), its internalization was dramatically increased only in HeLa cells.

Urea-Assisted Reconstitution of Discoidal High-Density Lipoprotein.

High-density lipoprotein (HDL) is a naturally occurring composite of lipids and lipid-binding proteins. The cholate dialysis method, first reported by Jonas in 1969, is the most widely used approach for reconstituting discoidal HDL (dHDL) in test tubes with phospholipids and the most dominant protein, apolipoprotein A-1 (apoA-I). Here, we show that a dHDL-relevant complex can also be prepared by gently mixing 1,2-dimyristoyl--glycero-3-phosphocholine (DMPC) and apoA-I or its mutants in ethanol/HO solutions containing urea at a concentration of a few molar and then incubating the mixture at the gel-liquid crystalline phase transition temperature in test tubes.