Impact of a physiological medium on the aggregation state of C60 and C70 fullerenes

Structural Researches of Carbonic Fluid Nanosystems

“…Its results testify that, first, being extracted from the C 60 /NMP solution, fullerene can transform into a nonpolar phase only in the molecular state [101], and, second, almost all fullerenes trans-form into the cluster state in the solution C 60 /NMP in the course of the time. The transition in time from the molecular solution into the colloid one in the C 60 /NMP system was studied in detail, by using the mass spectroscopy [102][103][104] and IR-spectroscopy [105] methods. The growth of fullerene clusters in those systems was described on the basis of kinetic equations from the nucleation theory [106][107][108][109][110].…”

“…Clusters in NMP are close-packed formations with insignificant (less than 10 vol.%) probable inclusions of hydrogen-containing molecules [112]. In further works [95,96,102,104,113,114], the mechanism of this reorganization was determined. Namely, the addition of water stimulates the detachment of separate C 60 molecules from the clusters, which results in an effective reduction of the number of clusters.…”

Liquid Systems with Fullerenes in Organic Solvents and Aqueous Media

“…The most wide-spread were the following ones: the size of aggregates, the remnants of the initial organic solvent, and the choice of the biological object to study. The lack of a detailed analysis of the structure of aqueous liquid systems with fullerenes -in particular, the size and morphology of aggregates -and a necessity to analyze the influence of the physiological environment on the structure of fullerene aggregates [77] considerably restricted the solution of this problem. Another problem consisted in that the aqueous systems produced using the solvent exchange methods were characterized by a substantial size polydispersity, with the average aggregate size being of about 70-90 nm.…”

Fullerenes as an Effective Amyloid Fibrils Disaggregating Nanomaterial

“…The impact of the synthesis procedure on the toxicity of fullerene aqueous solutions should also be considered. , Conflicting evidence concerning the fullerene water solutions toxicity presented in the literature have led to the understanding that the main parameters, which can be responsible for higher solution toxicity are the particle size, morphology, and primary solvent. ,, In particular, analysis of size-dependent toxicity of fullerenes reveal the smaller C 60 aggregates exhibit a stronger toxic effect compared to micrometer-sized aggregates. , However, this trend was not confirmed for particles of different sizes within the nanometer range. , Complicating matters further is the lack of information regarding the preparation technique dependent on the aggregation stability of fullerenes solutions in physiological media. ,, Nevertheless, it is generally agreed that a primary solvent plays a significant role in fullerenes toxicity. ,,, According to works of Yalkowsky and coauthors, NMP shows promise for various biomedical applications and used as solubilizer in the pharmaceutical industry. , There are a number of reasons for choosing of NMP as a solvent: (i) the ability to stabilize fullerenes other than hydroxylation (both hydrophobic and hydrophilic properties of complexes fullerenes/NMP); (ii) the possibility of further use of NMP-based fullerene aqueous solutions with the ability to control the size of the aggregates; (iii) sufficient stability of aqueous solutions in physiological environments, and last but not least, (iv) the acceptable toxicity. ,, Therefore, a solution of fullerenes in NMP is an ideal candidate for SANS measurements due to high enough concentrations in the initial fullerene solutions and thus wide possibilities to vary the concentration in the mixture.…”

“…32,36 Complicating matters further is the lack of information regarding the preparation technique dependent on the aggregation stability of fullerenes solutions in physiological media. 3,32,37 Nevertheless, it is generally agreed that a primary solvent plays a significant role in fullerenes toxicity. 3,29,33,38 According to works of Yalkowsky and coauthors, NMP shows promise for various biomedical applications and used as solubilizer in the pharmaceutical industry.…”