Abstract
This study deals with the development of a novel biocompatible cationized pullulan three‐dimensional matrix for gene delivery. A water‐soluble cationic polysaccharide, diethylaminoethyl‐pullulan (DEAE‐pullulan), was first synthesized and characterized. Fluorescence quenching and gel retardation assays evidenced the complexation in solution of DNA with DEAE‐pullulan, but not with neutral pullulan. On cultured smooth muscle cells (SMCs) incubated with DEAE‐pullulan and a plasmid vector expressing a secreted form of alkaline phosphatase (pSEAP), SEAP activity was 150‐fold higher than with pSEAP alone or pSEAP with neutral pullulan. DEAE‐pullulan was then chemically crosslinked using phosphorus oxychloride. The resulting matrices were obtained in less than a minute and molded as discs of 12 mm diameter and 2 mm thickness. Such DEAE‐pullulan 3D matrices were loaded with up to 50 μg of plasmid DNA, with a homogeneous plasmid loading observed with YOYO‐1 fluorescence staining. Moreover, the DEAE‐pullulan matrix was shown to protect pSEAP from DNase I degradation. Incubation of cultured SMCs with pSEAP‐loaded DEAE‐pullulan matrices resulted in significant gene transfer without cell toxicity. This study suggests that these cationized pullulan 3D matrices could be useful biomaterials for local gene transfer. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2007