Chong Su Cho — Page 2 | PubMed Health

PubMed2002

Preparation of alginate/galactosylated chitosan scaffold for hepatocyte attachment.

Galactose-carrying lactobionic acid was covalently coupled with chitosan for determining hepatocyte specificity. Galactosylated chitosan (GC) was reacted with Ca-alginate (ALG) gel through the electrostatic interaction of carboxylic groups of alginate with amine groups of GC. Highly porous, three-dimensional sponge composed of ALG and GC was prepared to provide specific hepatocyte recognition signals and enhance the mechanical property of the ALG sponge. Observation of the sponge through scanning electron microscopy revealed that sponge was a highly porous microstructure with interconnected pores. Porosity and pore size of the sponge were greatly dependent on the content and molecular weight of GC, and freezing temperature. The mechanical property of the ALG/GC sponge was enhanced with an increase of the GC content. Spheroid formation and viability of hepatocytes of the ALG/GC sponge were higher than those of the ALG one.

Alginates↗

PubMedDate not supplied

Receptor-mediated gene delivery into antigen presenting cells using mannosylated chitosan/DNA nanoparticles.

Dendritic cells (DCs) are professional antigen presenting cells that induce, sustain, and regulate immune responses. Gene modification of DCs is of particular interest for immunotherapy of diseases where the immunes system has failed or is abnormally regulated, such as in cancer or autoimmune disease. Gene transfer using non-viral vectors is a promising approach for the safe delivery of therapeutic DNA. Among various non-viral vectors, chitosan is considered to be a good candidate for gene delivery system, however, lack of cell specificity and low transfection of chitosan need to be overcome prior to clinical use. In this study, mannosylated chitosan (MC) was prepared to induce the receptor-mediated endocytosis and targeting into antigen presenting cells (APCs), especially DCs having mannose receptors. MC showed great ability to form complexes with DNA and showed suitable physicochemical properties for gene delivery system. It had low cytotoxicity and exhibited much enhanced gene transfer efficiency on the macrophage cell line than chitosan itself. Also, MC/DNA complex was more efficient for transferring IL-12 gene into DCs rather than water-soluble chitosan (WSC)/DNA one, which resulted in better induction of INF-gamma from DCs. Therefore, MC is a promising gene delivery system for repeated administration to maintain sustained gene expression, thereby opening the possibility for immunotherapy.

Animals↗