title: Regulation of singlet oxygen generation using single-walled carbon nanotubes.
abstract: We have designed a novel photodynamic therapy (PDT) agent using protein binding aptamer, photosensitizer, and single-walled carbon nanotube (SWNT). The PDT is based on covalently linking a photosensitizer with an aptamer then wrapping onto the surface of SWNTs, such that the photosensitizer can only be activated by light upon target binding. We have chosen the human alpha-thrombin aptamer and covalently linked it with Chlorin e6 (Ce6), which is a second generation photosensitizer. Our results showed that SWNTs are great quenchers to singlet oxygen generation (SOG). In the presence of its target, the binding of target thrombin will disturb the DNA interaction with the SWNTs and cause the DNA aptamer to fall off the SWNT surface, resulting in the restoration of SOG. This study validated the potential of our design as a novel PDT agent with regulation by target molecules, enhanced specificity, and efficacy of therapeutic function, which directs the development of photodynamic therapy to be safer and more selective.
authors.affiliation: Center for Research at the Bio/Nano Interface, Department of Chemistry and Physiology and Functional Genomics, University of Florida, Gainesville, Florida 32611-7200, USA.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Zhu
authors.forename: Zhiwen
authors.initials: Z
authors.lastname: Tang
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Phillips
authors.forename: Ronghua
authors.initials: R
authors.lastname: Yang
authors.forename: Hui
authors.initials: H
authors.lastname: Wang
authors.forename: Weihong
authors.initials: W
authors.lastname: Tan
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry / Q000528:radiation effects; D004277:DNA, Single-Stranded / Q000737:chemistry / Q000528:radiation effects; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000528:radiation effects; D010777:Photochemistry; D010778:Photochemotherapy / Q000379:methods*; D012680:Sensitivity and Specificity; D026082:Singlet Oxygen / Q000737:chemistry* / Q000528:radiation effects; D013917:Thrombin / Q000235:genetics; D013997:Time Factors; D014466:Ultraviolet Rays
chemical_list: D052157:Aptamers, Nucleotide; D004277:DNA, Single-Stranded; D037742:Nanotubes, Carbon; D026082:Singlet Oxygen; D013917:Thrombin