Assessment of protective effect of polycation on plasmid DNA attached on the metal surface by SPR

作者：Bao Junbo; Song Cunxian^*

来源：E-Polymers, 2008, 8(1): 125.

DOI：10.1515/epoly.2008.8.1.1441

Surface modification of the metal is a critical procedure for gene therapy on the metal implants, such as stent and artificial joint. Polycations can condense with DNA by self-assembly, form polyplexes spontaneously as a result of electrostatic interactions and protect DNA from degradation by DNase. The ability of chitosan, polyethyleneimine (PEI), and poly(amidoamine) (PAMAM) dendrimers to condense plasmid DNA(pDNA) was determined by electrophoresis, X-ray photoelectron spectroscopy (XPS) and surface plasmon resonance (SPR). Polycation's attachment of pDNA to the metal surface was confirmed by XPS which showed no phosphorus peaks on the interface showing the protective effect on pDNA from DNase degradation. Polycations with higher molecular weight or hyperbranched or dendrimer structures can fulfill many of the requirements for effective gene protection from DNase degradation. Chitosan with higher molecular weight (>= 200 kDa) has superior efficiency to protect pDNA against DNase degradation on the surface of the gold chip. Hyperbranched PEIs and PAMAM dendrimers, even with lower molecular weight (for example, 20kDa for PEI, 50kDa for G5) can protect pDNA against DNase degradation. The results of this study present a platform for further optimization studies of polycation-based gene delivery systems.

• 出版日期2008-9-20