title: Dextran-protamine polycation: an efficient nonviral and haemocompatible gene delivery system.
abstract: Despite the remarkable progress in the field of gene therapy with viral vectors, nonviral vectors have attracted great interests due to their unique properties. Imparting desired characteristics to nonviral gene delivery systems requires the development of cationic polymers. The purpose of this work was to design a cationic derivative (Dex-P) of dextran using protamine in order to assert target specific cellular binding. Our objective was to elucidate the potential use of Dex-P as a haemocompatible, nontoxic and efficient nonviral candidate for gene therapy. Nanoplexes were prepared with calf thymus DNA and Dex-P. Derivatization was confirmed by FTIR, gel permeation chromatography and TNBS assay. Dynamic light scattering and TEM studies determined the size and morphology of the nanoplex. The buffering behaviour was assessed by acid base titration. Complexation stability was evaluated using agarose gel electrophoresis and EtBr displacement assay. The protection of ctDNA from nuclear digestion and the effect of plasma components towards stability of the nanoplexes were also analyzed. Various haemocompatible studies were performed to check haemolysis, aggregation, clotting time, and complement activation. Transfection and cytotoxicity experiments were performed in vitro. The nanosize, spherical shape and stability of nanoplexes were affirmed. Various experiments conducted confirmed Dex-P to be nontoxic and haemocompatible. Transfection experiments revealed the capability of Dex-P to facilitate high gene expression and cellular uptake in HepG2 cells. With the improved physicochemical, biological and transfection properties, Dex-P seems to be a promising gene delivery system.
authors.affiliation: Division of Biosurface Technology, Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences & Technology, Trivandrum, Kerala, India.
authors.forename: Jane Joy
authors.initials: JJ
authors.lastname: Thomas
authors.forename: M R
authors.initials: MR
authors.lastname: Rekha
authors.forename: Chandra P
authors.initials: CP
authors.lastname: Sharma
mesh_terms: D000818:Animals; D002417:Cattle; D045744:Cell Line, Tumor; D004247:DNA / Q000737:chemistry / Q000235:genetics; D003911:Dextrans / Q000737:chemistry*; D018014:Gene Transfer Techniques; D015316:Genetic Therapy / Q000379:methods; D006461:Hemolysis / Q000187:drug effects; D056945:Hep G2 Cells; D006801:Humans; D046529:Microscopy, Electron, Transmission; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D011073:Polyamines; D000071228:Polyelectrolytes; D011108:Polymers / Q000737:chemistry / Q000494:pharmacology; D011479:Protamines / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D014162:Transfection / Q000379:methods
chemical_list: D004247:DNA; D003911:Dextrans; D011073:Polyamines; D000071228:Polyelectrolytes; D011108:Polymers; D011479:Protamines; C427203:calf thymus DNA