A Experimental Study Of Periodontal Tissue Engineering Based On Human Periodontal Ligament Cells And β-TCP In BALB/c-nu Mice

Objective: To establish an in vivo model of nude mice implanted subcutaneously with periodontal ligament cells (PDLCs) and β —TCP , and to investigate the differentiation of PDLCs and the expression of osteocalcin (OCN) in PDLC, and to investigate the possibility of construction the periodontal tissue.Material and methods: PDLCs were obtained from explant cultures of human healthy periodontal ligaments taken from premolars that had been extracted for orthodontic reasons. PDLCs at passage four were used in all experiments. PDLCs were seeded onto β —TCP for seven days in vitro. Then they were implanted subcutaneously in BALB/c-nu mice. The control group were implanted by β -TCP only on the back bilaterally. At 4 , 8 and 12 weeks after implantation, the implants were harvested and the harvests were examined by histological and immunofluorescence analysis.Result:1. PDLCs attached to β —TCP and assembled dense cluster around the edge of β —TCP after they were seeded onto the β —TCP in vitro.2. HE staining demonstrated obviously degradation of β —TCP . PDLCs was obvious proliferation and expressed a lot of extracellular matrix.3. Immunofluorescence analysis demonstrated PDLCs significantly expressed osteocalcin more in experimental group compared to the control group.4. In experimental group, there are significant differences of osteocalcin production at 4, 8, and 12 weeks.Conclusion:1. P —TCP is propitious to promote PDLCs' proliferation.2. The degradation of ￡ —TCP was more obvious after the composites were implanted into the nude mice at 12 weeks than 8 weeks and 4 weeks, and the interspace ofP-TCP was replaced by new formation.3. 3 — TCP stimulated the osteogenic differentiation of PDLCs as determined by the expression of osteocalcin.4. It is feasible to use ￡ —TCP as scaffold in periodontal tissue engineering.