Study on the antigenicity of metallofullerenol: antibody production, characterization, and its enzyme immunoassay application.

With their intriguing structures and properties, metallofullerenols have attracted considerable attention in biological and medical applications. Due to the increasing biomedical interest, effective detection methods are important to monitor and control metallofullerenols. However, the detection of metallofullerenols becomes very difficult after polyhydroxylated modification due to the lack of detectable features. Antibody-based immunoassay methods have been important tools for detection and will better meet the needs of analysis of metallofullerenols. Thus, the antigenicity of metallofullerenol has been studied for the first time. In this study, no immune response was detected when metallofullerenol Gd@C82(OH)x was used as immunogen. However, the polyclonal antibody against metallofullerenol was produced using metallofullerenol-KLH (keyhole limpet hemocyanin) as immunogen, indicating that metallofullerenol can act as hapten. The specificity of the obtained antibody was investigated. It has been found that the hydroxyl groups on the surface of the carbon cage, the encapsulated metal, and the size and shape of the carbon cage did not affect the recognition specificity of the antibody. Based on the obtained antibody, an indirect competitive enzyme immunoassay was developed for the determination of metallofullerenol with detection limits of 18 ng/mL in PBS. This enzyme immunoassay method was successfully used to detect metallofullerenol in serum. This work can provide an innovative way to determine metallofullerenols. Graphical abstract The polyclonal antibody against metallofullerenol was produced using metallofullerenol-KLH (keyhole limpet hemocyanin) as immunogen. Based on the obtained antibody, a competitive enzyme immunoassay was developed for the determination of metallofullerenol.

Biomedical activities of endohedral metallofullerene optimized for nanopharmaceutics.

Endohedral metallofullerenes, a novel form of carbon-related nanomaterials, currently attract wide attention for their potential applications in biomedical fields such as therapeutic medicine. Most endohedral metallofullerenes are synthesized using C60 or higher molecular weight fullerenes because of the limited interior volume of fullerene. It is known that the encapsulated metal atom has strong electronic interactions with the carbon cage in metallofullerenes. Gd@C82 is one of the most important molecules in the metallofullerene family, known as Magnetic Resonance Imaging (MRI) contrast agent candidate for diagnostic imaging. Gadolinium endohedral metallofullerenol (e.g., Gd@C82(OH)22) is a functionalized fullerene with gadolinium trapped inside carbon cage. Our group previously demonstrated that the distinctive chemical and physical properties of Gd@C82(OH)22 are dependent on the number and position of the hydroxyl groups on the fullerene cage. The present article summarizes our latest findings of biomedical effects of Gd@C82(OH)22 and gives rise to a connected flow of the existing knowledge and information from experts in the field. It briefly narrates the synthesis and physico-chemical properties of Gd@C82(OH)22. The polyhydroxylated nanoparticles exhibit the enhanced water solubility and high purity, and were tested as a MRI contrast agent. Gd@C82(OH)22 treatment inhibited tumor growth in tumor-bearing nude mice. Although the precise mechanisms of this action are not well defined, our in vitro data suggest involvements of improved immunity and antioxidation by Gd@C82(OH)22 and its size-based selective targeting to tumor site. The review critically analyzed the relevant data instead of fact-listing, and explained the potential for developing Gd@C82(OH)22 into a diagnostic or therapeutic agent.

Summary of special issue on gadolinium bioeffects and toxicity with a look to the future.

This summary attempts to provide forward-looking concepts regarding gadolinium related toxicity, as discussed in further detail in this issue.