title: Migration of periodontal ligament fibroblasts on nanometric topographical patterns: influence of filopodia and focal adhesions on contact guidance.
abstract: Considered to be the "holy grail" of dentistry, regeneration of the periodontal ligament in humans remains a major clinical problem. Removal of bacterial biofilms is commonly achieved using EDTA gels or lasers. One side effect of these treatment regimens is the etching of nanotopographies on the surface of the tooth. However, the response of periodontal ligament fibroblasts to such features has received very little attention. Using laser interference lithography, we fabricated precisely defined topographies with continuous or discontinuous nanogrooves to assess the adhesion, spreading and migration of PDL fibroblasts. PDL fibroblasts adhered to and spread on all tested surfaces, with initial spreading and focal adhesion formation slower on discontinuous nanogrooves. Cells had a significantly smaller planar area on both continuous and discontinuous nanogrooves in comparison with cells on non-patterned controls. At 24 h post seeding, cells on both types of nanogrooves were highly elongated parallel to the groove long axis. Time-lapse video microscopy revealed that PDL fibroblast movement was guided on both types of grooves, but migration velocity was not significantly different from cells cultured on non-patterned controls. Analysis of filopodia formation using time-lapse video microscopy and labeling of vinculin and F-actin revealed that on nanogrooves, filopodia were highly aligned at both ends of the cell, but with increasing time filopodia and membrane protrusions developed at the side of the cell perpendicular to the cell long axis. We conclude that periodontal ligament fibroblasts are sensitive to nanotopographical depths of 85-100 µm, which could be utilized in regeneration of the periodontal ligament.
authors.affiliation: Graduate Program of Biomedical Engineering, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, Canada. dhamil2@uwo.ca
authors.forename: Douglas W
authors.initials: DW
authors.lastname: Hamilton
authors.forename: Christine J
authors.initials: CJ
authors.lastname: Oates
authors.forename: Abdollah
authors.initials: A
authors.lastname: Hasanzadeh
authors.forename: Silvia
authors.initials: S
authors.lastname: Mittler
mesh_terms: D000199:Actins / Q000737:chemistry; D018441:Biofilms; D002448:Cell Adhesion; D002465:Cell Movement; D004492:Edetic Acid / Q000737:chemistry; D005347:Fibroblasts / Q000166:cytology; D022001:Focal Adhesions / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D018625:Microscopy, Atomic Force / Q000379:methods; D008855:Microscopy, Electron, Scanning / Q000379:methods; D018715:Microscopy, Video / Q000379:methods; D010513:Periodontal Ligament / Q000166:cytology* / Q000378:metabolism; D011554:Pseudopodia / Q000378:metabolism*; D013997:Time Factors
chemical_list: D000199:Actins; D004492:Edetic Acid