How to cite this article: Tseng W-C, Su L-Y, Fang T-Y. 2013. pH responsive PEGylation through metal affinity for gene delivery mediated by histidine-grafted polyethylenimine. J Biomed Mater Res Part B 2013:101B:375–386.
pH responsive PEGylation through metal affinity for gene delivery mediated by histidine-grafted polyethylenimine†
Article first published online: 19 NOV 2012
Copyright © 2012 Wiley Periodicals, Inc.
Journal of Biomedical Materials Research Part B: Applied Biomaterials
Volume 101B, Issue 2, pages 375–386, February 2013
How to Cite
Tseng, W.-C., Su, L.-Y. and Fang, T.-Y. (2013), pH responsive PEGylation through metal affinity for gene delivery mediated by histidine-grafted polyethylenimine. J. Biomed. Mater. Res., 101B: 375–386. doi: 10.1002/jbm.b.32848
- Issue published online: 8 JAN 2013
- Article first published online: 19 NOV 2012
- Manuscript Accepted: 10 OCT 2012
- Manuscript Revised: 7 OCT 2012
- Manuscript Received: 22 MAY 2012
- National Science Council. Grant Number: 100-2221-E-011-012-MY3
- drug delivery/release;
- gene therapy/gene delivery;
Polyethylene glycol (PEG) has been used to enhance the stability of a gene delivery system. The most commonly used approach is to add the PEG molecule by way of chemical conjugation. In this study, we prepared PEG-bearing nitrilotriacetic acid (ntaPEG) followed by chelation with either nickel or zinc ions. Polyethylenimine was grafted with histidine (hisPEI) and used as a primary gene carrier to form complexes with DNA. PEGylation was performed by incubating the complexes with chelated ntaPEG. It was noted that the coating of the chelated ntaPEG could provide a shielding effect against aggregation induced by bovine serum albumin and DNA release induced by heparin displacement, respectively. The coating was also found to improve cellular viability and maintain the transfection efficiency at a moderate level. The coated ntaPEG could dissociate from the complexes in an acidic condition of pH 4, suggesting that dePEGylation might occur in some acidic intracellular organelles, such as endosomes. This simple and effective PEGylation approach could be extended to other delivery systems to enhance the stability and to facilitate the dePEGylation process. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2013.