Aligned fiber matrices as potential scaffolds for periodontal tissue engineering

Objectives: The aim of the study was to fabricate aligned electrospun poly-L-lactic acid (PLLA) mats and to decellularise bovine which is a ligament as naturally aligned collagen fiber matrix. Also, to investigate the response of periodontal ligament fibroblasts (PDLF) to these biomaterials . Method: An 8% PLLA polymer solution was prepared and the electrospun to produced aligned scaffolds. Random PLLA fibre scaffolds were fabricated as a control. Periodontal ligament fibroblasts (PDLF) were seeded onto the PLLA scaffolds and cultured for varying periods of time. Specimens of bovine anterior cruciate ligaments (ACL) were decellularised using 0.25% Triton X-100 and 0.25% sodium deoxycholate. The decellularisation process was assessed using DNA quantification assay and nuclear staining. The resultant constructs were analysed by scanning electron microscopy (SEM), confocal microscopy and immunohistochemistry. Result: Scaning electron microscopy confirmed alignment of electrospun PLLA fibers and PDLF were observed to attach to the scaffold fibres. Phalloidin staining of the PDLF actin filaments and confocal microscopy showed that the cells were elongated in shape and oriented along the long-axis of the fibres. Also, a higher level of cellular activity was observed by PDLFs cultured on aligned fibres. In addition, a greater staining density for collagen I was seen in the aligned fibres constructs. These results indicate that fibre alignment may exert an effect on the phenotype of periodontal ligament fibroblasts. Nuclear staining with Hoechst and DAPI staining confirmed efficient removal of cells from the decellularised ligament. Also, SEM micrographs of decellularised ligament showed that the ligament morphology was maintained throughout the decellularisation process. PDLF attached and oriented along the long-axis of the collagen fibres when cultured for 7 days on the decellularised ligament. Conclusion: Aligned fibre matrices such as electrospun PLLA aligned scaffolds and decellularised natural ligaments may be suitable candidates for periodontal tissue engineering.