Sizes, zeta potentials, and polydispersity index (PDI) of liposomes and MP-LP were measured by Zetasizer Nano (ZS90, Malvern, UK). Morphology of liposomes and MP-LP were observed using a Tecnai G2 Spirit transmission microscope (FEI) after staining with 2% (w/v) phosphotungstic acid. Coomassie blue staining (Beyotime, China) was performed to investigate the protein profiles of MP-LP. To evaluate the stability of liposomes and MP-LP, size, and PDIs were measured after storage, liposomes were stored at 4 °C while MP-LP were stored at −80 °C after vacuum freezing and drying.
The amount of TPL encapsulated in MP-LP was measured using high-performance liquid chromatography (HPLC) system (H20AT SHIMADZU, Japan) equipped with an Agilent TC-C18 column (250 mm ×4.6 mm, 5 μm, Agilent). A mobile phase of acetonitrile: water = 40:60 at a flow rate of 1.00 mL/min at column temperature of 30 °C was used. Absorbance at 218 nm was detected to measure the concentration of TPL.
To measure TPL release, 50 mg of TPL@MP-LP in 1 mL PBS was placed in a dialysis bag (30 kDa). The bag was immersed in a beaker containing 25 mL of PBS at 37 °C with stirring (200 rpm). Samples (500 μL) were collected at 1, 2, 4, 6, 8, 12, 24, 36, and 48 h post placing and were analyzed by HPLC.
The amount of TPL encapsulated in MP-LP was measured using high-performance liquid chromatography (HPLC) system (H20AT SHIMADZU, Japan) equipped with an Agilent TC-C18 column (250 mm ×4.6 mm, 5 μm, Agilent). A mobile phase of acetonitrile: water = 40:60 at a flow rate of 1.00 mL/min at column temperature of 30 °C was used. Absorbance at 218 nm was detected to measure the concentration of TPL.
To measure TPL release, 50 mg of TPL@MP-LP in 1 mL PBS was placed in a dialysis bag (30 kDa). The bag was immersed in a beaker containing 25 mL of PBS at 37 °C with stirring (200 rpm). Samples (500 μL) were collected at 1, 2, 4, 6, 8, 12, 24, 36, and 48 h post placing and were analyzed by HPLC.