Aggregation Behavior and Antioxidant Properties of Amphiphilic Fullerene C₆₀ Derivatives Cofunctionalized with Cationic and Nonionic Hydrophilic Groups

Abstract

Amphiphilic derivatives of fullerene C60 are attractive from viewpoints of supramolecular chemistry and biomedicine. The establishment of relationships among the molecular structure, aggregation behavior and properties such as scavenging radicals of the amphiphilic C60 derivatives is the key to push these carbon nanomaterials to real applications. In this work, six monosubstituted C60 derivatives were synthesized by a one-step quaternization of their neutral precursors, which bear Percec monodendrons terminated with oligo­(poly­(ethylene oxide)) (o-PEO) chain(s). The main difference among the C60 derivatives lies in the number and substituted position of the o-PEO chain(s) within the Percec monodendron. Derivative with a 4-substitution of the o-PEO chain still showed limited solubility in water. Other derivatives possessing two or three o-PEO chains exhibited much improved solubilities and rich aggregation behavior in water. It was found that the formation of aggregates is regulated both by the number and the substituted pattern of the o-PEO chains. Typical morphologies include nanosheets, nanowires, vesicles, nanotubes, and nanorods. Although the structures of the C60 derivatives are different from those of traditional surfactants, their aggregation behavior can be also well explained by applying the theory of critical packing parameter. Interestingly, the capabilities of the C60 derivatives to scavenge the hydroxyl radicals (OH· –) followed the same order of their solubility in water, where the compound bearing three o-PEO chains with a 2,3,4-substitution got the champion quenching efficiency of ∼97.79% at a concentration of 0.15 mg·mL–1 (∼0.11 mmol·L–1).

Magnetic and Biocompatible Fullerenol/Fe(III) Microcapsules with Antioxidant Activities

“…It then slows down at relatively large concentrations of the microcapsule, which reaches ∼86% at 100 μg mL –1 and ∼93% at 1000 μg mL –1 (Figure a, b, Figure S9). The capability of the microcapsules to scavenge OH· – is comparable to that exhibited by the cationic C 60 derivative bearing a Percec monodendron terminated with three oligo­(poly­(ethylene oxide)) ( o -PEO) chains at the 3,4,5-position, which shows polymorphic aggregation behavior in water with the formation of vesicles, nanorods, and nanotubes . It is slightly weaker than that exhibited by the C 60 derivative with three o -PEO chains at the 2,3,4-position in the Percec monodendron, which forms nanowires in water .…”

Developing [60]Fullerene Nanomaterials for Better Photodynamic Treatment of Non-Melanoma Skin Cancers

“…The MonoaminoC 60 forms larger aggregates around 354 nm with observed zeta potential at +31 mV; in contrast HexakisaminoC 60 seems to predominantly aggregate around 99 nm, indicating a surface of charge of +29 mV. Both aminofullerenes present a relatively good degree of stability, and the smaller aggregates and possibly a different morphology of Hexakisadduct aggregates may be partially explained by a different critical packing parameter p …”

“…41 The MonoaminoC 60 forms larger aggregates around 354 nm with observed zeta potential at +31 mV; in contrast Hexakisami-noC 60 seems to predominantly aggregate around 99 nm, indicating a surface of charge of +29 mV. Both aminofullerenes present a relatively good degree of stability, and the smaller aggregates and possibly a different morphology of Hexakisadduct aggregates may be partially explained by a different critical packing parameter p. 42 The infrared spectra of engineered water-soluble fullerenes (MonoaminoC 60 and HexakisaminoC 60 ) have been analyzed considering two spectral regions: (1) 2250−3800 cm −1 and (2) 400−1900 cm −1 (Figure 2C). The bands arrangement found in relation to the HexakisaminoC 60 and MonoaminoC 60 are quite similar, wherein small differences as for the number of bands, their intensity, or positions result from the number of functional groups anchored to the fullerene scaffold.…”

Attaching a Dipeptide to Fullerene as an Antioxidant Hybrid against DNA Oxidation

“…Some previous reports might be beneficial for understanding our results. The affinity of hydrophobic fullerene toward protein is higher than that of fullerenol, a water-soluble derivative of fullerene, because the hydrophobic fullerene moiety is able to control the aggregation status of the fullerenyl derivative, and thus, to influence antioxidative property …”

“…The affinity of hydrophobic fullerene toward protein is higher than that of fullerenol, a water-soluble derivative of fullerene, 30 because the hydrophobic fullerene moiety is able to control the aggregation status of the fullerenyl derivative, and thus, to influence antioxidative property. 31 To gain further insight into the function of the fullerene moiety on the antioxidative effect, we select 7 and 8 as well as 13 and 14 as the model compounds to test their binding constants (K) with the DNA strand. As shown in eq 8, if a guest compound can intercalate with DNA stand to form a DNA complex, the constant (K) of the guest molecule binding with the DNA strand is expressed by eq 9.…”