title: Disassembly of layer-by-layer films of plasmid DNA and reducible TAT polypeptide.
abstract: This paper reports the disassembly of layer-by-layer (LbL) films of plasmid DNA and a reducible cationic polypeptide. To utilize a reducing microenvironment of cellular plasma membrane as a potential trigger, LbL films are assembled to contain both DNA and the TAT-based polypeptide (PTAT) with reducible disulfide bonds in the backbone. The assembly and disassembly processes are monitored by goniometry, ellipsometry, and atomic force microscopy (AFM). The structure of the PTAT films is compared with that of non-reducible poly(L-lysine) (PLL) films. Both PTAT and PLL films exhibit exponential growth but with the contact angle alternating between characteristic values. Ellipsometry and AFM show a gradual and complete disassembly of the PTAT but not the PLL films in a 24h period in the reducing environment in vitro. This study suggests a potential of using reducible LbL films for controlled DNA delivery.
authors.affiliation: Department of Pharmaceutical Sciences, Wayne State University, Detroit, MI 48202, USA.
authors.forename: Jenifer
authors.initials: J
authors.lastname: Blacklock
authors.forename: Hitesh
authors.initials: H
authors.lastname: Handa
authors.forename: Devika
authors.initials: D
authors.lastname: Soundara Manickam
authors.forename: Guangzhao
authors.initials: G
authors.lastname: Mao
authors.forename: Ashis
authors.initials: A
authors.lastname: Mukhopadhyay
authors.forename: David
authors.initials: D
authors.lastname: Oupický
mesh_terms: D004247:DNA / Q000737:chemistry* / Q000648:ultrastructure; D015696:Gene Products, tat / Q000737:chemistry* / Q000648:ultrastructure; D018625:Microscopy, Atomic Force; D010455:Peptides / Q000737:chemistry*; D010957:Plasmids / Q000737:chemistry* / Q000648:ultrastructure
chemical_list: D015696:Gene Products, tat; D010455:Peptides; D004247:DNA