Anchoring of self-assembled plasmid DNA/ anti-DNA antibody/cationic lipid micelles on bisphosphonate-modified stent for cardiovascular gene delivery
Anchoring of self-assembled plasmid DNA/ anti-DNA antibody/cationic lipid micelles on bisphosphonate-modified stent for cardiovascular gene delivery
Blog Article
Guilei Ma,1,# Yong Wang,1,# Ilia Fishbein,2 Mei Yu,1 Linhua Zhang,1 Ivan S Alferiev,2 Jing Yang,1 Cunxian Song,1 Robert J Levy2 1Institute of Biomedical Engineering, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin, People's Republic of China; 2Children's Hospital of Philadelphia, Abramson Bong Bowls Research Building, Philadelphia, PA, USA #These authors contributed equally to this work Purpose: To investigate the anchoring of plasmid DNA/anti-DNA antibody/cationic lipid tri-complex (DAC micelles) onto bisphosphonate-modified 316 L coronary stents for cardiovascular site-specific gene delivery.Methods: Stents were first modified with polyallylamine bisphosphonate (PAA-BP), thereby enabling the retention of a PAA-BP molecular monolayer that permits the anchoring (via vector-binding molecules) of DAC micelles.DAC micelles were then chemically linked onto the PAA-BP-modified stents by using N-succinimidyl-3-(2-pyridyldithiol)-propionate (SPDP) as a crosslinker.Rhodamine-labeled DNA was used to assess the anchoring of DAC micelles, and radioactive-labeled antibody was used to evaluate binding capacity and stability.
DAC micelles (encoding green fluorescent protein) were tethered onto the PAA-BP-modified stents, which were assessed in cell culture.The presence of a PAA-BP molecular monolayer on the steel surface was confirmed by X-ray photoelectron spectroscopy and atomic force microscope analysis.Results: The anchoring of DAC micelles was generally uniform and devoid of large-scale patches of defects.Isotopic quantification confirmed that the amount of antibody chemically linked on the Model Truck stents was 17-fold higher than that of the physical adsorbed control stents and its retention time was also significantly longer.
In cell culture, numerous green fluorescent protein-positive cells were found on the PAA-BP modified stents, which demonstrated high localization and efficiency of gene delivery.Conclusion: The DAC micelle-immobilized PAA-BP-modified stents were successful as a gene delivery system.Gene delivery using DAC micelle-tethered stent-based PAA-BP functionalization should be suitable for a wide array of single or multiple therapeutic gene strategies, and could be used on cardiovascular metallic implants for achieving efficient gene therapy.Keywords: stent, polyallylamine bisphosphonate, plasmid DNA, micelles, gene delivery.