Fig. 1: Development of SM-derived Chol Lipo (Lipo-SM-Chol).

a Synthesis of SM-Chol conjugate with a carbonate ester bond (SM-C-Ester-Chol), an ester bond (SM-Ester-Chol), a glycine bond (SM-Glycine-Chol), a disulfide bond (SM-CSS-Chol) with a longer linker or thioketal bond (SM-SCS-Chol) with a longer linker. b A table depicting the physicochemical characterizations of Lipo composed of sterol-modified phospholipids (SMLs) from Avanti Polar Lipids with equivalent (eq.) 66.7 mol % Chol, SM/Chol or five SM-Chol with equivalent (eq.) 35 mol % Chol. d.nm, diameter values in nanometers. c DLS size distribution by intensity for Lipo-SM/Chol and Lipo-SM-Chol, DLS: dynamic light scattering. d The monitoring of the DLS size by intensity over time in 5% dextrose at 4 °C. e The percentage of remaining SM-CSS-Chol measured by LC-MS/MS after incubated Lipo-SM-CSS-Chol with or without the presence of GSH at 37 °C. f, g Leakage profiles for calcein-loaded Lipo (eq. 40 mol % Chol) in high osmotic gradient (f) or 30% fetal bovine serum (g) at 37 °C. h Relative Chol exchange rates at 37 °C with eq. 40 mol % Chol in the Lipo., i-l Thermotropic phase transition behavior determined by differential scanning calorimetry (DSC). DSC thermograms of Lipo-SM/Chol (i) and Lipo-SM-CSS-Chol (j) at various eq. mol % Chol. The effects of Chol or SM-CSS-Chol on transition temperature (k) and enthalpy (l). m–o Atomic force microscopy (AFM) to assess the height of Lipo-SM/Chol (m) and Lipo-SM-CSS-Chol (n) and the lipid bilayer rigidity was shown as by the ratio of height/diameter (H/D) value (o)⁴³ (n = 3 independent experiments, similar results were observed). Data in b, d, e–h, o are expressed as mean ± s.d. (n = 3 independent experiments). Statistical significance was determined by one-way ANOVA followed by Tukey’s multiple comparisons test, two-tailed, unpaired Student’s t-test for e. Source data are provided as a Source Data file.