Microtopographic Effect of Honeycomb Film on the Periodontal Ligament Cells

Objectives: This study was aimed to investigate the possibility of biocompatible honeycomb-patterned polymer film (HF) as a scaffold for periodontal regeneration. Methods: HFs were prepared from poly(ε-caprolactone) (PCL) and amphiphilic, and 5, 10, or 15 ìm diameter of pores were cast by water droplet array method (Figure). Periodontal ligament (PDL) cells from 6 extracted human molars were cultured on HFs, or PCL plane substrate (PS) and positive control of glass (G) as controls for 4 hours (h) and up to 28 days. Cultured cells were histologically analyzed by SEM and confocal laser microscopy. Results: After 24h on HFs, PDL cells were attached to pillars in the honeycomb structure with the pseudopodiums. On the 10 and 15 µm pored HFs, spindle shape cells started to migrate into the structural lumen of films. At 28 days, cultured PDL cells on HFs (10 µm) formed the multilayered cell sheet like-structure with the penetration of cells into the pores. Penetrating cells showed the heteromorphic shape with extending dendritic processes into pores. On the control substrates, adhered PDL cells maintained the flat shape until 24h, and changed into the spindle shape after 72h. The adhesion of PDL to PS was vulnerable, and exfoliated cells were observed after 72h. Cell counting assay also showed that the cell numbers of control and experimental groups was almost similar until 24h. PDL cells on 5ìm pored HF were still countable at 72h, and grown up at 60% proportionally to positive control, G. Thus, HF tended to successfully increase the cell numbers as compared to PS, suggesting the topographic effect of honeycomb film with a pillar structure to enhance the proliferation and extension of the cells. Conclusions: HF is applicable to the periodontal therapy as a cell-interactive scaffold for the periodontal tissue regeneration.