Layered Double Hydroxide Nanomaterials Encapsulating Angelica gigas Nakai Extract for Potential Anticancer Nanomedicine

Abstract

We prepared hybrids consisting of Angelica gigas Nakai (AGN) root or flower extract and layered double hydroxide (LDH) for potential anticancer nanomedicine, as decursin species (DS) in AGN are known to have anticancer activity. Dimethylsulfoxide solvent was determined hybridization reaction media, as it has affinity to both AGN and LDH moiety. In order to develop inter-particle spaces in LDH, a reversible dehydration-rehydration, so-called reconstruction route, was applied in AGN-LDH hybridization. Quantitative analyses on AGN-LDH hybrids indicated that the content of DS was two times more concentrated in the hybrids than in extract itself. Using X-ray diffraction, FT-IR spectroscopy, scanning electron microscopy, and zeta-potential measurement, we found that AGN extract moiety was incorporated into inter-particle spaces of LDH nanoparticles during the reconstruction reaction. Time-dependent DS release from hybrids at pH 7.4 (physiological condition) and pH 4.5 (lysosomal condition) exhibited a pH-dependent release of extract-incorporated LDH hybrids. An anticancer activity test using HeLa, A549, and HEK293T cells showed that the AGN-LDH hybrid, regardless of extract type, showed enhanced anticancer activity compared with extract alone at an equivalent amount of DS, suggesting a nanomedicine effect of AGN-LDH hybrids.

Zingiber officinale Extract (ZOE) Incorporated with Layered Double Hydroxide Hybrid through Reconstruction to Preserve Antioxidant Activity of ZOE against Ultrasound and Microwave Irradiation

“…As zeta-potential of ZOE–LDH still resided in the positive region, it suggested that ZOE was encapsulated in the interparticle space of LDH, rather than attached on the surface of LDH. This result was similar to our previous result that Angelica gigas Nakai extract incorporated in LDH hybrid showed positive zeta-potential [43]. Based on XRD patterns, IR spectra, SEM images, and zeta-potential, we could conclude that MgFe–LDH lost its lamellar structure upon calcination, and the original layered structure was partially recovered to develop the interparticle space of LDH with intact ZOE moiety.…”

Incorporation of Glycine max Merrill Extract into Layered Double Hydroxide through Ion-Exchange and Reconstruction

“…It was worthy to note that the GML-R hybrid, completely different from GML-I, showed house-of-cards like structure (Figure 2d), suggesting that particle thickness of LDH becomes thinner and that the layers were randomly stacked with GM moiety. This morphology tends to have inter-particle space, which might encapsulate large biomolecules in natural extract as reported previously [28]. We could observe a few LDO-like particles in the SEM image of GML-R which corresponded to the XRD result.…”

“…The severe crystallinity change is thought to be due to large molecular dimension of GM moiety. In our previous report, incorporation of Angelica gigas Nakai natural extract into LDH through reconstruction significantly reduced crystallinity of LDH due to perturbed stacking of LDH layers by the steric hindrance of large organic species in natural extract [28].…”

“…For reconstruction, the pristine LDH was calcined to layered double oxide (LDO). The calcination process was carried out at 400 °C for 9 h by using an electric muffle furnace [28].…”

“…Jiang et al reported that ethanol extract of Angelica gigas Nakai enhanced chemoprevention and chemotherapeutic properties against prostate cancer [27]. If natural plant extract was incorporated with a drug carrier such as LDH, the obtained hybrids would protect the activity of extract against the external harsh environment, facilitate drug delivery into the target cell, and release therapeutic components in a controlled manner [9,28]. At this stage, we noticed that the incorporation method would affect the biological behaviors of extract-LDH hybrids.…”