title: DNA condensation and cell transfection properties of guanidinium calixarenes: dependence on macrocycle lipophilicity, size, and conformation.
abstract: Calix[n]arenes functionalized with guanidinium groups at the upper rim and alkyl chains at the lower rim bind to DNA, condense it, and in some cases, promote cell transfection depending on their structure and lipophilicity. Atomic force microscopy (AFM) studies indicate that upon DNA binding the hydrophobic association of the lipophilic chains of cone guanidinium calix[4]arenes drives the formation of intramolecular DNA condensates, characterized by DNA loops emerging from a dense core. Furthermore, hexyl and octyl chains confer to these calixarenes cell transfection capabilities. Conversely, larger and conformationally mobile calix[6]- and calix[8]arene methoxy derivatives form intermolecular aggregates characterized by "gorgonlike" structures composed of multiple plectomenes. These adducts, in which interstrand connections are dominated by electrostatic interactions, fail to promote cell transfection. Finally, calix[4]arenes in a 1,3-alternate conformation show an intermediate behavior because they condense DNA, but the process is driven by charge-charge interactions.
authors.affiliation: Dipartimento di Chimica Organica e Industriale, Università degli Studi, Viale G. P. Usberti 17/A, 43100 Parma, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Sansone
authors.forename: Miroslav
authors.initials: M
authors.lastname: Dudic
authors.forename: Gaetano
authors.initials: G
authors.lastname: Donofrio
authors.forename: Claudio
authors.initials: C
authors.lastname: Rivetti
authors.forename: Laura
authors.initials: L
authors.lastname: Baldini
authors.forename: Alessandro
authors.initials: A
authors.lastname: Casnati
authors.forename: Sara
authors.initials: S
authors.lastname: Cellai
authors.forename: Rocco
authors.initials: R
authors.lastname: Ungaro
mesh_terms: D047250:Calixarenes / Q000737:chemistry*; D004247:DNA / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D018625:Microscopy, Atomic Force; D008968:Molecular Conformation; D021241:Spectrometry, Mass, Electrospray Ionization; D014162:Transfection
chemical_list: D047250:Calixarenes; D004247:DNA