title: Selective DNA Recognition and Cytotoxicity of Water-Soluble Helical Metallosupramolecular Polymers.
abstract: Water-soluble helical Fe(II)-based metallosupramolecular polymers ((P)- and (M)-polyFe) were synthesized by 1:1 complexation of Fe(II) ions and bis(terpyridine)s bearing a (R)- and (S)-BINOL spacer, respectively. The binding affinity to calf thymus DNA (ct-DNA) was investigated by titration measurements. (P)-PolyFe with the same helicity as B-DNA showed 40-fold higher binding activity (Kb= 13.08 × 107M-1) to ct-DNA than (M)-polyFe. The differences in binding affinity were supported by electrochemical impedance spectroscopy analysis. The charge-transfer resistance (Rct) of (P)-polyFe increased from 2.5 to 3.9 kΩ upon DNA binding, while that of (M)-polyFe was nearly unchanged. These results indicate that ionically strong binding of (P)-polyFe to DNA chains decreased the mobility of ions in the conjugate. Unique rod-like images were obtained by atomic force microscopy measurement of the DNA conjugate with (P)-polyFe, likely because of the rigid binding between DNA chains and the polymer. Differences in polymer chirality lead to significantly different cytotoxicity levels in A549 cells. (P)-PolyFe showed higher binding affinity to B-DNA and much higher cytotoxicity than (M)-polyFe. The helicity in metallosupramolecular polymer chains was important not only for chiral recognition of DNA but also for coordination to a biological target in the cellular environment.
authors: Electronic Functional Macromolecules Group, National Institute for Materials Science (NIMS) , Tsukuba 305-0044, Japan.
authors: Utpal
authors: U
authors: Rana
authors: Electronic Functional Macromolecules Group, National Institute for Materials Science (NIMS) , Tsukuba 305-0044, Japan.|International Center for Materials Nanoarchitectonics (MANA), NIMS , Tsukuba 305-0044, Japan.
authors: Chanchal
authors: C
authors: Chakraborty
authors: Electronic Functional Macromolecules Group, National Institute for Materials Science (NIMS) , Tsukuba 305-0044, Japan.
authors: Rakesh K
authors: RK
authors: Pandey
authors: Electronic Functional Macromolecules Group, National Institute for Materials Science (NIMS) , Tsukuba 305-0044, Japan.
authors: Md Delwar
authors: MD
authors: Hossain
authors: Nanotechnology Innovation Station, NIMS , 1-2-1 Sengen, Tsukuba 305-0047, Japan.
authors: Reiko
authors: R
authors: Nagano
authors: Nanotechnology Innovation Station, NIMS , 1-2-1 Sengen, Tsukuba 305-0047, Japan.
authors: Hiromi
authors: H
authors: Morita
authors: Nanotechnology Innovation Station, NIMS , 1-2-1 Sengen, Tsukuba 305-0047, Japan.
authors: Shinya
authors: S
authors: Hattori
authors: Nanotechnology Innovation Station, NIMS , 1-2-1 Sengen, Tsukuba 305-0047, Japan.
authors: Takashi
authors: T
authors: Minowa
authors: Electronic Functional Macromolecules Group, National Institute for Materials Science (NIMS) , Tsukuba 305-0044, Japan.
authors: Masayoshi
authors: M
authors: Higuchi
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D060326:Chemistry Techniques, Synthetic; D004247:DNA / Q000378:metabolism*; D058266:Dielectric Spectroscopy / Q000379:methods; D004354:Drug Screening Assays, Antitumor / Q000379:methods; D005452:Fluoresceins / Q000378:metabolism; D006801:Humans; D058085:Iron Compounds / Q000737:chemistry; D051379:Mice; D018625:Microscopy, Atomic Force; D041681:NIH 3T3 Cells / Q000187:drug effects; D011108:Polymers / Q000737:chemistry* / Q000378:metabolism* / Q000494:pharmacology; D012995:Solubility; D014867:Water / Q000737:chemistry
chemical_list: D000970:Antineoplastic Agents; D005452:Fluoresceins; D058085:Iron Compounds; D011108:Polymers; D014867:Water; C085925:calcein AM; D004247:DNA; C427203:calf thymus DNA