|Budget Amount *help
¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 2003: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 2002: ¥1,200,000 (Direct Cost: ¥1,200,000)
1.Effects of chitin and chitosan on glycosaminoglycan (GAG) and proteoglycan (PG) synthesis : We evaluated effects of chitin and chitosan on GAG and PG synthesis with special staining (Safranin O stain for PG and Alcian blue stain for GAG) and image analyzing using granulation tissue induced by chitin and chitosan. Chitin was found to increase GAG synthesis, while to decrease PG synthesis.
2.Effects of molecular weight and deacetylation on wound healing by chitin/chitosan : We studied effects of molecular weight and deacetylation (DAC) on wound healing by chitin/chitosan using linear incisional wound model in rats. We measured break strength of the wound and collagenase activity in the tissue as an indicator of wound healing. Results were as follows :
1)Effect of molecular weght : Wound break strengths in all samples were increased significantly compared to that of control (saline). In both chitin (GlcNAc, NACOS, chitin) and chitosan (GlcN, COS, chitosan) groups, oligomers (NACOS, COS) w
ere most effective. When the chitin and chitosan groups were compared, the chitosan group was higher than the chitin group in each molecular size. Collagenase activities in all samples were increased significantly compared to that of control (saline). In the chitosan group, monomer (GlcN) was most effective, while there was no difference in the chitin group.
2)Effect of deacetylation : The levels of both paramers in all samples were significantly higher than that of control. The higher degree of deacetylation showed, the stronger break strength and more collagenase activity. In histologically, more activated fibroblasts were observed in the sample with higher degree of deacetylation.
3.Effects of chitin and chitosan on release of type I collagenase (MMP-1) of fibroblasts : We evaluated effects of chitin and chitosan on release of type I collagenase (MMP-l) of fibroblasts using adult human fibroblast (HSF39) and neonatal human fibroblasts (HFFWC, NHDF, HFF11). In all cells, MMP-1 activity in the medium was highest at 72 hrs after incubation. Levels of MMP-1 in the medium were enhanced significantly in the presence of interleukin-1 (IL-1) in HSF39 and HFF11, while those level in HFFWC and NHDF was not affect by IL-1. All samples without G1cN increased significantly release of MMP-l from HSF39, while there was no significant change in MMP-1 level in the presence of all samples in HFFWC. The present study suggests that induction of MMP-l is dependent on origin of fibroblasts. From the fact that oligomers and monomers of chitin and chitosan influenced MMP-1 activity in HSF39, it was suggested that MMP-1 activity continue until finish of complete biodegradation of chitin and chitosan. Less