title: Chitosan chip and application to evaluate DNA loading on the surface of the metal.
abstract: The plasmid DNA (pDNA) loading by cationic polymers or/and cationic lipids is essential for gene therapy, especially for metal implants such as stents and artificial joints. Polycations can condense with pDNA by self-assembly, forming polyplexes spontaneously as a result of electrostatic interactions to carry and transfer pDNA in vivo. Cationic polymers, such as chitosan, can also protect pDNA from degradation by DNase. In this study, a chitosan chip was prepared and loaded with pDNA layer-by-layer with polycation/cationic lipids. By real-time surface plasmon resonance (SPR) sensorgram, pDNA loading ability, layer stability and protective effect on pDNA from DNase degradation have been detected. Chitosan can increase the pDNA loading amount of N-(1-(2,3-dioleoyloxy)propyl)-N, N, N-trimethylammonium methyl sulphate (DOTAP) and Lipofectmine 2000 (Lipo) on the chip surface. Different flow rates can affect the pDNA loading on the chitosan chip, and it is not significant at a lower flow rate. The pDNA protection by chitosan with different molecular weights from DNase degradation was also tested. Polycationic chitosan with higher molecular weight (> or =200 kDa) can fulfil the requirements for effective gene protection from DNase degradation. The results of this study present a platform for further optimization studies of polycation-based gene delivery systems.
authors.affiliation: Key Laboratory of Biomedical Materials of Tianjin, Institute of Biomedical Engineering, Peking Union Med College, Chinese Academy of Medical Sciences, Tianjin 300192, People's Republic of China.
authors.forename: Bao
authors.initials: B
authors.lastname: Junbo
authors.forename: Song
authors.initials: S
authors.lastname: Cunxian
mesh_terms: D040761:Biomimetic Materials / Q000737:chemistry; D002412:Cations; D048271:Chitosan / Q000737:chemistry*; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D003460:Crystallization / Q000379:methods; D004337:Drug Carriers / Q000737:chemistry; D015316:Genetic Therapy / Q000295:instrumentation; D008055:Lipids / Q000737:chemistry*; D008422:Materials Testing; D008670:Metals / Q000737:chemistry*; D010316:Particle Size; D010957:Plasmids / Q000737:chemistry*; D020349:Surface Plasmon Resonance / Q000379:methods*; D013499:Surface Properties; D014162:Transfection / Q000379:methods*
chemical_list: D002412:Cations; D020099:Coated Materials, Biocompatible; D004337:Drug Carriers; D008055:Lipids; D008670:Metals; D048271:Chitosan