Periodontal therapy has dealt primarily with attempts at arresting progression of disease, however, more recent techniques have focused on regenerating the periodontal ligament having the capacity to regenerate the periodontium. The effect of chitosan(poly-N-acetyl glucosaminoglycan), a carbohydrate biopolymer extracted from chitin, on periodontal ligament regeneration is of particular interest.

The purpose of this study was to evaluate the effect of chitosan on the human periodontal ligament fibroblasts(hPDLFs) in vitro , with special focus on their proliferative properties by MTT assay, the synthesis of type I collagen by reverse transcription-polymerase chain reaction(RT-PCR) and the activity of alkaline phosphatase(ALP). Fibroblast populations were obtained from individuals with a healthy periodontium and cultured with αMEM as the control group. The experimental groups were cultured with chitosan in concentration of 0.01, 0.1, 1, 2mg/ml.

The results are as follows;

1. Chitosan-induced proliferative responses of hPDLFs reached a plateau at the concentration of 0.1mg/ml (p<0.05).

2. When hPDLFs were stimulated with 0.1mg/ml chitosan, mRNA expression of type I collagen was up-regulated.

3. When hPDLFs were stimulated with 0.1mg/ml chitosan, ALP activity was significantly upregulated(p<0.05).

In summary, chitosan(0.1mg/ml) enhanced the type I collagen synthesis in the early stage, and afterwards, facilitated differentiation into osteogenic cells. The results of this in vitro experiment suggest that chitosan potentiates the differentiation of osteoprogenitor cells and may facilitate the formation of bone.