title: Gold nanoparticles modified with self-assembled hybrid monolayer of triblock aptamers as a photoreversible anticoagulant.
abstract: We demonstrated that thrombin-binding aptamer-conjugated gold nanoparticles (TBA-Au NPs), prepared from a self-assembled hybrid monolayer (SAHM) of triblock aptamers on Au NPs (13 nm), can effectively inhibit thrombin activity toward fibrinogen. The first block poly(adenine) at the end of the triblock TBA was used for the self-assembly on Au NP surface. The second block, in the middle of TBA, was composed of oligonucleotides that could hybridize with each other. The third block, containing TBA15 (15-base, binding to the exosite I of thrombin) and TBA29 (29-base, binding to the exosite II of thrombin) provided bivalent interaction with thrombin. The SAHM triblock aptamers have optimal distances between TBA15 and TBA29, aptamer density, and orientation on the Au NP surfaces. These properties strengthen the interactions with thrombin (Kd=1.5 × 10(-11)M), resulting in an extremely high anticoagulant potency. The thrombin clotting time mediated by SAHM TBA15/TBA29-Au NPs was >10 times longer than that of four commercially available drugs (heparin, argatroban, hirudin, or warfarin). In addition, the rat-tail bleeding assay time further demonstrated that the SAHM TBA15/TBA29-Au NPs were superior to heparin. The SAHM TBA15/TBA29-Au NPs exhibited excellent stability in the human plasma (half-life >14 days) and good biocompatibility (low cytotoxicity and hemolysis). Most interestingly, the inhibition by SAHM TBA15/TBA29-Au NPs was controllable by the irradiation of green laser, via heat transfer-induced TBA release from Au NPs. Therefore, these easily prepared (self-assembled), low cost (non-thiolated aptamer), photo-controllable, multivalent TBA15/TBA29-Au NPs (high density of TBA15/TBA29 on Au NPs) show good potential for the treatment of various diseases related to blood-clotting disorders. Our study opens up the possibility of regulation of molecule binding, protein recognition, and enzyme activity using SAHM aptamer-functionalized nanomaterials.
authors.affiliation: Department of Bioscience and Biotechnology, National Taiwan Ocean University, Keelung 20224, Taiwan.
authors.forename: San-Shan
authors.initials: SS
authors.lastname: Huang
authors.affiliation: Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan.
authors.forename: Shih-Chun
authors.initials: SC
authors.lastname: Wei
authors.affiliation: Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan.
authors.forename: Huan-Tsung
authors.initials: HT
authors.lastname: Chang
authors.affiliation: Department of Bioscience and Biotechnology, National Taiwan Ocean University, Keelung 20224, Taiwan.
authors.forename: Han-Jia
authors.initials: HJ
authors.lastname: Lin
authors.affiliation: Department of Bioscience and Biotechnology, National Taiwan Ocean University, Keelung 20224, Taiwan; Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung 20224, Taiwan; School of Pharmacy, College of Pharmacy, Kaohsiung Medical University, Kaohsiung 80708, Taiwan. Electronic address: huanging@ntou.edu.tw.
authors.forename: Chih-Ching
authors.initials: CC
authors.lastname: Huang
mesh_terms: D000818:Animals; D000925:Anticoagulants / Q000737:chemistry / Q000494:pharmacology*; D052157:Aptamers, Nucleotide / Q000737:chemistry / Q000494:pharmacology*; D003692:Delayed-Action Preparations / Q000737:chemistry*; D005340:Fibrinogen / Q000378:metabolism*; D006046:Gold / Q000737:chemistry*; D006801:Humans; D008027:Light; D008297:Male; D053768:Metal Nanoparticles / Q000737:chemistry*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013917:Thrombin / Q000378:metabolism*
chemical_list: D000925:Anticoagulants; D052157:Aptamers, Nucleotide; D003692:Delayed-Action Preparations; C081676:thrombin aptamer; D006046:Gold; D005340:Fibrinogen; D013917:Thrombin
keywords: Anticoagulants; Aptamers; Gold nanoparticles; Self-assemble; Thrombin