Methods: Primary human periodontal ligament cells (PDLCs) were treated with various concentrations of acemannan in vitro. New DNA synthesis, mRNA expression of osteocalcin and bone sialoprotein, expression of VEGF and type I collagen, expression of osteopontin and osteonectin, alkaline phosphatase activity, and mineralized nodule formation were determined using [3H]-thymidine incorporation, reverse transcription-polymerase chain reaction, enzyme-linked immunoabsorbent assay, western blot analysis, biochemical assay, and Alizarin Red staining, respectively. In in vivo study, premolar Class II furcation defects were created in four mongrel dogs. Acemannan sponges were applied into the defects. Untreated defects were used as a negative control. The amount of new bone, cementum, and periodontal ligament formation were evaluated at 30 and 60 days post-operation. To demonstrate cellular response to acemannan, acemannan was labeled by fluorescein isothiocyanate and cultured with PDLCs. Photographs of PDLCs were recorded at 0, 1, 4, 6 and 8 hours under a fluorescent microscope.
Results: Acemannan significantly enhanced PDLC proliferation, VEGF and type I collagen expression. Acemannan accelerated osteogenic differentiation of PDLCs by significant upregulating mRNA expression of BSP and OC, expression of OPN and ON, ALPase activity and mineral deposition. Acemannan induced periodontal regeneration in class II furcation defects. Acemannan significantly increased the percentage of new bone formation at 30 and 60 days post-implantation compare with control group. Acemannan significantly increased the percentage of new cementum and PDL formation at 60 days.
Conclusion: Acemannan increased PDLC proliferation, growth factor and extracellular matrix synthesis, differentiation, and mineralization in vitro, and enhanced periodontal regeneration in Class II furcation defects.