No abstract

The coating of pDNA/chitosan complexes with high-molecular-weight HA augmented the stability and cellular transfection ability of the complexes after lyophilization-rehydration.

Mixing a low-molecular-weight heparin (e.g., fragmin) with protamine results in the formation of waterinsoluble fragmin/protamine microparticles (F/P MPs) approximately 0.5-3 lm in diameter. In this study, we investigated the ability of F/P MPs to improve the viability of Lewis lung (3LL) cancer cells, B16 (B16) melanoma cells, and a human hepatoma (Huh7) cell line in a suspension culture, and the ability of F/P MPs to enhance tumor take rate and growth in vivo. F/P MPs rapidly bound to the surface of the cells. The interaction of the cells with F/P MPs induced formations of the tumor cell/F/P MP aggregates and maintained the viability of those cells in suspension for at least 3 days. The addition of F/P MPs with FGF-2 significantly enhanced the growth rate of the cells in a fetal bovine serum (FBS)-free medium. The tumor cell/F/P MP aggregates, which were subcutaneously injected into the backs of mice, significantly stimulated the formation and growth of subcutaneous tumors consisting of 3LL, B16, and Huh7 cells. Furthermore, the tumors produced by injection of 7.5 9 10 5 Huh7 into nude mice did grow only with F/P MPs. Thus F/P MPs can utilize as cell carrier for tumor cell transplantation.

Successful gene therapy depends on the development of effective gene carriers. Naturally occurring chitosan has been employed widely as a non-viral gene carrier because of its low toxicity, low immunogenicity, biocompatibility, and biodegradability. In this review, we summarize the utilization of chitosan, modified chitosan, and chitosan-containing ternary complexes as gene carriers. In particular, we discuss the influence of the physicochemical features of pDNA/chitosan complexes on their functions, such as stability and gene transfer into cells.