Drug-Loaded Nanocarriers Composed of Cholesteryl Oleate Crystal Cores and Multiple-Nanosheet Shells of γ-Cyclodextrin Inclusion Complex Crystals

Abstract

In this study, we prepared drug-loaded nanocarriers made of cholesteryl oleate (ChO) and γ-cyclodextrin (γ-CD). A nanosuspension (nanosuspension-I, NS-I) containing nanoparticles with a mean size of approximately 170 nm was obtained through the solvent-diffusion method using ethanol. A second nanosuspension (nanosuspension-II, NS-II), which was prepared by freeze-drying and redispersion of NS-I, exhibited an increased particle size of approximately 210 nm. Cryogenic transmission electron microscopy (cryo-TEM) and atomic force microscopy (AFM) force−distance curves indicated that the nanoparticles in NS-I were oblong and soft. However, those in NS-II were angular and stiff, and, interestingly, multiple nanosheets covered the solid−liquid interface. Synchrotron wide-angle X-ray diffraction (WAXD) analysis of NS-II indicated that the nanoparticles in it had a core−shell structure, where the ChO crystal in the inner core was covered by multiple nanosheets of ChO/γ-CD inclusion complex crystals. The X-ray peak analysis suggested that the γ-CD columns of the nanosheets were vertically stacked onto the ChO crystal interface. It was found that the nanosheets on the nanoparticle interface were formed during the freezing process. A model drug carbamazepine (CBZ) was loaded into the ChO/γ-CD nanoparticles by pre-dissolving CBZ in ethanol during the solvent-diffusion process. Cryo-TEM, 1 H NMR, ζ-potentials, and synchrotron WAXD indicated that CBZ was unexpectedly loaded into the shell as a CBZ/γ-CD inclusion complex crystalline nanosheet. The specific nanosheet structure, where ChO and CBZ coexisted in the same crystal of γ-CD, could achieve CBZ loading in the nanoparticles. ChO/γ-CD nanoparticles with the unique core−shell structure are expected to perform as practical carriers for drug delivery.

Self‐Assembly of Rod‐Coil Bottlebrush Copolymers into Degradable Nanodiscs with a UV‐Triggered Self‐Immolation Process

“…To further evaluate the drug loading capacity of our polymer nanodiscs, doxorubicin (DOX) was encapsulated with a drug loading content of 9.5 wt % and a loading efficiency of 19.6 % (Figure S21). The results were comparable to the poly(ethyl glyoxylate)‐ b ‐poly(ethylene oxide) nanoparticles reported by the Gillies group earlier [51] and exhibited higher loading capacity than common 2D polymer materials with crystalline cores [52] …”

“…The results were comparable to the poly(ethyl glyoxylate)-b-poly(ethylene oxide) nanoparticles reported by the Gillies group earlier [51] and exhibited higher loading capacity than common 2D polymer materials with crystalline cores. [52] In conclusion, we have successfully synthesised a tadpole-like amphiphilic BBC with a rod-coil architecture. While a coil-rod-coil bottlebrush-containing macromolecule has been studied before, [27,29] polymer discs were only obtained in organic solvent mixtures and featured no stimuli-responsive properties.…”

SCD1 inhibition enhances the effector functions of CD8+ T cells via ACAT1‐dependent reduction of esterified cholesterol

“…ChO (0.05 mmol)/γ‐CD (1.5 mmol) nanoparticles were prepared by the solvent diffusion method in which ethanol containing ChO was added to a γ‐CD aqueous solution. 21 , 22 …”

Pickering emulsions stabilized by β-CD microcrystals: Construction and interfacial assembly mechanism

“…Therefore, it can be speculated that these regular lamellar crystals (large particles) were amphiphilic lamellar inclusions formed by further self-assembly of the supramolecular (small particles) formed by β-CD and GO. Similarly, Ishimoto et al ( 35 ) also confirmed the formation of crystalline flake shells between host and guest in the study of the formation of γ-CD and cholesterol oleate in drug-carrying nanocarriers.…”