Chitosan chip and application to evaluate DNA loading on the surface of the metal

• Published in: Biomedical materials (Bristol) Vol. 4; no. 1; p. 011002
• Main Authors: Junbo, Bao, Cunxian, Song
• Format: Journal Article
• Language: English
• Published: England 01-02-2009
• Subjects: Biomimetic Materials - chemistry; Cations; Chitosan - chemistry; Coated Materials, Biocompatible - chemistry; Crystallization - methods; Drug Carriers - chemistry; Genetic Therapy - instrumentation; Lipids - chemistry; Materials Testing; Metals - chemistry; Particle Size; Plasmids - chemistry; Surface Plasmon Resonance - methods; Surface Properties; Transfection - methods
• ISSN: 1748-605X
• DOI: 10.1088/1748-6041/4/1/011002

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.