[70]Fullerenes Assists the Formation of Phospholipid Bicelles at Low Lipid Concentrations

The incorporation of neutral [70]fullerenes (C70) led to the bicelles formation at relatively low lipid concentration range from neutral lipid mixtures (DMPC/DHPC). Furthermore, the C70 addition resulted in the formation of large bicelles with a radius of ca. 100 nm in contrast to C70-free bicelles that were formed from anionic lipid mixtures (DMPC/DHPC/DMPG). The stabilization of these bicelles was attributed to C70 incorporation into the membranes.This file includes Supporting Information.This work was supported by JSPS KAKENHI a Grant-in-Aid for Scientific Research (B) (Grant No. 25288037), a Grant-in-Aid for Challenging Exploratory Research (Grant Nos. 24655128 and 25650053), and a Grant-in-Aid for Young Scientists (A) (Grant No. 24681028)

Improved photodynamic activities of liposome‐incorporated [60]fullerene derivatives bearing a polar group

[60]Fullerene (C60) derivatives were incorporated into liposomes using a fullerene exchange method involving the transfer of the fullerene from the cavity of two γ‐cyclodextrin molecules to a liposome. A lipid‐membrane‐incorporated C60 derivative bearing a polar group showed much higher photodynamic activity than the analogous system incorporating pristine C60.This work was supported by JSPS KAKENHI Grant‐in‐Aid for Scientific Research (B) (Grant No. JP16H04133) and Grant‐in‐Aid for Challenging Exploratory Research (Grant No. JP16K13982)

Formation of β‐(1,3‐1,6)‐D‐glucan‐complexed [70]fullerene and its photodynamic activity towards macrophages

[70]Fullerene was dissolved in water by the complexation with β‐1,3‐glucan using a mechanochemical high‐speed vibration milling apparatus. The photodynamic activity of β‐1,3 glucan‐complexed C70 was highly dependent on the expression level of dectin‐1 on the cell surfaces of macrophages. The photodynamic activity increased as a result of a synergistic effect between β‐1,3‐glucan‐complexed 1’‐acetoxychavicol acetate and the C70 complex.This work was supported by JSPS KAKENHI Grant‐in‐Aid for Scientific Research (B) (Grant No. JP16H04133), Grant‐in‐Aid for Scientific Research (C) (Grant No. 26350528) and Grant‐in‐Aid for Challenging Exploratory Research (Grant No. JP16K13982)

Porphyrin‐uptake in liposomes and living cells using an exchange method with cyclodextrin

The water‐solubilisation of porphyrin derivatives is very important for biological applications. Although liposomal drug carriers for porphyrin derivatives have shown significant promise in the field of medicinal chemistry (e.g., as sensitisers for photodynamic therapy), it is currently not possible to prepare lipid‐membrane‐incorporated tetraphenylporphyrin (TPP) with a high concentration of TPP using conventional methods. In this study, we have succeeded in preparing lipid-membrane‐incorporated TPP and zinc(II) tetraphenylporphyrin (ZnTPP) from the corresponding TPP or ZnTPP•cyclodextrin complex using the exchange method in lipid‐membranes composed of liposomes. Furthermore, the exchange method allowed for the incorporation of TPP or ZnTPP into the plasma membranes of HeLa cells. However, it was not possible to prepare lipid‐membrane‐incorporated porphyrin derivatives with polar and hydrophilic groups in the meso positions using this exchange reaction.Electronic supplementary information (ESI) available: Experimental procedures, 1H NMR spectra, DLS measurements, cryo-TEM images, phase contrast and fluorescence images. See DOI: 10.1039/c5ra24985This work was supported by JSPS KAKENHI a Grant‐in‐Aid for Scientific Research (B) (Grant No. 25288037) and a Grant‐in‐Aid for Young Scientists (A) (Grant No. 24681028)

Gold Nanoparticle Inclusion into Protein Nanotube as a Layered Wall Component

We describe the synthesis, structure, and catalytic activity of human serum albumin (HSA) nanotubes (NTs) including gold nanoparticles (AuNPs) as a layered wall component. The NTs were fabricated as an alternating layer-by-layer assembly of AuNP and HSA admixture (a negatively charged part) and poly-l-arginine (PLA, a positively charged part) into a track-etched polycarbonate membrane (400 nm pore diameter) with subsequent dissolution of the template. SEM images showed the formation of uniform hollow cylinders of (PLA/AuNP-HSA)₃ with a 426 ± 12 nm outer diameter and 65 ± 7 nm wall thickness. Transmission electron microscopy and energy dispersive X-ray measurements revealed high loading of AuNPs in the tubular wall. HSAs bind strongly onto the individual AuNP (<i>K</i> = 1.25 × 10⁹ M^–1), generating a core–shell AuNP-HSA corona, which is the requirement of the robust NT formation. Calcination of the (PLA/AuNP-HSA)₃ NTs at 500 °C under air yielded red solid NTs composed of thermally fused AuNPs. From the mass decrease by heat treatment, we calculated the weight of the organic components (PLA and HSA) and thereby constructed a six-layer model of the tube. The (PLA/AuNP-HSA)₃ NTs serve as a heterogeneous catalyst for reduction of 4-nitrophenol with sodium borohydrate. Furthermore, implantation of the stiff (PLA/AuNP-HSA)₃ NTs vertically onto glass plate produced uniformly cylindrical tube arrays

Regioselective Recognition of a [60]Fullerene-Bisadduct by Cyclodextrin

The three different regioisomers of bis-<i>N</i>-methylfulleropyrrolidines have been separated by controlling the relative amounts of γ-cyclodextrin and dimethyl sulfoxide (DMSO) contained in solutions of these compounds. When a small amount of γ-CDx was used in a mechanochemical high-speed vibration milling apparatus, the <i>trans-1</i> and <i>trans-2</i>•γ-CDx complexes were separated from the <i>trans-3</i>•γ-CDx complex. In contrast, <i>trans-3</i> was extracted in a relatively high ratio with an excess of γ-CDx. The addition of DMSO to aqueous solutions of the fullerene derivative•γ-CDx complexes allowed for the three regioisomers to be obtained in high purity (>95%). The basis for the observed regioselective separation was a competition between the relative stabilities and solubilities of the complexes in the water and water-DMSO solvents. The stabilities of the complexes in water were assessed by the number of hydrogen bonding interactions between the two γ-CDx units using molecular dynamics simulations. To the best of our knowledge, this is the first reported example of the isolation of the different regioisomers of fullerene derivatives using host–guest complexes

[70]Fullerenes Assist the Formation of Phospholipid Bicelles at Low Lipid Concentrations

The incorporation of neutral [70]­fullerenes (C₇₀) led to bicelle formation in a relatively low lipid concentration range from neutral lipid mixtures (DMPC/DHPC). Furthermore, C₇₀ addition resulted in the formation of large bicelles with a radius of ca. 100 nm, in contrast to C₇₀-free bicelles that were formed from anionic lipid mixtures (DMPC/DHPC/DMPG). The stabilization of these bicelles was attributed to C₇₀ incorporation into the membranes