Applications Of Fullerene Nanoparticles In Photodynamic Therapy And Antioxidant Damage

Fullerene nanoparticles,with their unique electronic structures,fascinatingphysicochemicalpropertiesandsuperiorbiomedical characteristics,such as large surface area,unsaturated double bands,easy surface modification,good stability,high antioxidant ability and excellent biocompatibility,have attracted extensive attention in the field of biomedicine,especially in tumor treatment and repair of anti-oxidative damage.Based on the physical and chemical properties of fullerenes,three kinds of water-soluble fullerenes nanomaterials were prepared,and their chemical structures and related properties were systematically studied,which were applied in the fields of photodynamic therapy for tumors and cytoprotective effect against oxidative damage.The results are summarized as follows:1.A kind of water-soluble fullerene nanomaterial C₆₀-OH-GSH was synthesized by electrophilic addition reaction of the endogenous substance reduced glutathione（GSH）with C₆₀.The modification of GSH improves the water solubility and retains the hyper conjugated structure of C₆₀.C₆₀-OH-GSH nanoparticles of uniform size show excellent stability in different physical media.Furthermore,C₆₀-OH-GSH at low concentration under natural light can generate sufficient reactive oxygen species inducing tumor cell apoptosis,while in the dark it exhibits no negative effect on normal cells even at high concentrations,making it a safe and efficient photosensitizer applied in treatment of lesions and surface tumors in clinically accessible fibers.2.Water-soluble fullerene-polymer nanocomposite C₆₀-PDA-PEI has been initially synthesized via the combination of mussel-inspired chemistry and Michael addition.In a weakly alkaline solution,dopamine self-polymerizes to generate polydopamine（PDA）film,which is coated on the surface of the C₆₀nanoclusters to form an interface material connecting the organic phase and the inorganic phase.The structure of catechins and imines in polydopamine could react with the amino group by Michael addition,so the water-soluble polymer PEI was introduced to the surface of fullerenes modified by PDA to obtain the water-soluble fullerene nanocomposite C₆₀-PDA-PEI and its chemical composition and structure was confirmed by TEM,DLS,FT-IR,XPS and TGA.Benefiting from the relatively complete conjugate structure and water-soluble polymer,C₆₀-PDA-PEI displayed excellent water solubility and efficient ¹O₂ generation under light,possessing the good ability of cleaving closed supercoiled DNA to nicked DNA.This universal approach described in this work is capable of introducing many other functional molecules onto PDA-modified fullerenes,thus extending the possible applications of fullerene-based species in many fields of biological technology and pharmaceutical chemistry.3.One water-soluble fullerene derivative C₆₀-PDA-GSH was synthesized with two-step method,and then its structural characterization and performance measurement were carried out.The results showed that C₆₀-PDA-GSH had excellent biosafety and free radical scavenging ability.At low concentrations,it could protect against a variety of cellular oxidative stress damage induced by H₂O₂.C₆₀-PDA-GSH was distributed in mitochondria and lysosome after being taken up by the cells,and was enriched in mitochondria,which could effectively improve the mitochondrial membrane potential depolarization caused by oxidative stress injury and play a protective role in vivo.C₆₀-PDA-GSH nanoparticles have potential application in the field of biomedicine and cosmetics as an effective anti-oxidative damage reagent.