ABSTRACT
ObjectiveThe aim of the present study was to investigate the incorporation of plasmid DNA (pDNA) onto a coronary stent by chemo-immuno-conjugation for achieving site-specific gene delivery.MethodsA gene eluting stent was fabricated by reacting with polyallylamine bisphosphonate (PAA-BP) to introduce amine reactive groups on the surface.Then an anti-DNA antibody was chemically coupled and pDNA was immunologically tethered on the stent surface.Radioactive-labeled antibody was used to evaluate binding capacity and stability.ResultsThe presence of amine groups on the modified stent surface was confirmed by XPS and AFM analysis.The isotope label assay indicated that the amount of antibody chemically linked on the stents was 15-fold higher than that of the control stent and its retention time was also significantly longer.ConclusionThe results suggested that a large amount of reactive amine groups were introduced on the PAA-BP modified 316L coronary stent surface.This study provide a potential metal surface modification method that could facilitate coupling and tethering of biological molecules such as anti-DNA antibody and plasmid DNA (pDNA) to achieve sustained and highly localized gene delivery for substrate-mediated gene transfection.