title: The electrokinetic characterization of gold nanoparticles, functionalized with cationic functional groups, and its' interaction with DNA.
abstract: Gold nanoparticles have attracted strong biomedical interest for drug delivery due to their low toxic nature, surface plasmon resonance and capability of increasing the stability of the payload. However, gene transfection represents another important biological application. Considering that cellular barriers keep enclosed their secret to deliver genes using nanoparticles, an important step can be achieved by studying the functionalization of nanoparticles with DNA. In the present contribution the synthesis of nanoparticles consisting of a gold core coated with one or more layers of amino acid (l-lysine), and cationic polyelectrolytes (poly-ethyleneimine and poly-l-lysine) is reported. All nanoparticles were subjected to dynamic light scattering, electrophoretic mobility measurements, UV-vis optical spectrophotometry analysis and transmission electron microscopy imaging. In addition, the adsorption of DNA plasmid (pSGS) with linear and supercoiled configurations was studied for those gold nanoparticles under the most suitable surface modifications. Preliminary results showed that the gold nanoparticles functionalized with poly-ethyleneimine and poly-l-lysine, respectively, and bound to linear DNA configurations, present in absolute value a higher electrophoretic mobility irrespective of the pH of the media, compared to the supercoiled and nicked configuration. The findings from this study suggest that poly-ethyleneimine and poly-l-lysine functionalized gold nanoparticles are biocompatible and may be promising in the chemical design and future optimization of nanostructures for biomedical applications such as gene and drug delivery.
authors.affiliation: Discipline of Biochemistry, University of KwaZulu-Natal, Private Bag X 54001, Durban 4000, South Africa; Department of Chemistry, University of Zululand, Private Bag X1001, KwaDlangezwa 3886, South Africa; Department of Applied Physics, Hospital Universitario San Cecilio, University of Granada, Granada, Spain. Electronic address: geraldinelazarus@yahoo.co.uk.
authors.forename: Geraldine Genevive
authors.initials: GG
authors.lastname: Lazarus
authors.affiliation: Department of Chemistry, University of Zululand, Private Bag X1001, KwaDlangezwa 3886, South Africa.
authors.forename: Neerish
authors.initials: N
authors.lastname: Revaprasadu
authors.affiliation: Department of Applied Physics, Hospital Universitario San Cecilio, University of Granada, Granada, Spain.
authors.forename: Julián
authors.initials: J
authors.lastname: López-Viota
authors.affiliation: Discipline of Biochemistry, University of KwaZulu-Natal, Private Bag X 54001, Durban 4000, South Africa.
authors.forename: Moganavelli
authors.initials: M
authors.lastname: Singh
mesh_terms: D002412:Cations / Q000737:chemistry*; D002951:Citrates / Q000737:chemistry; D004247:DNA / Q000378:metabolism*; D004560:Electricity; D004586:Electrophoresis; D006046:Gold / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008027:Light; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D009994:Osmolar Concentration; D010084:Oxidation-Reduction; D011094:Polyethyleneimine / Q000737:chemistry; D011107:Polylysine / Q000737:chemistry; D012542:Scattering, Radiation; D013056:Spectrophotometry, Ultraviolet; D055672:Static Electricity
chemical_list: D002412:Cations; D002951:Citrates; D011107:Polylysine; D006046:Gold; D011094:Polyethyleneimine; D004247:DNA
keywords: Cytotoxicity; DNA; Electrophoretic mobility; Gold nanoparticles