Evaluation of Random and Aligned Polycaprolactone Nanofibrous Electrospun Scaffold for Human Periodontal Ligament Engineering in Biohybrid Titanium Implants

Abstract

Background: Stem cells are introduced to regenerate some living tissue to restore function and longevity. The study aims to isolate in vitro human periodontal ligament stem cells (hPDLSCs) and investigate their proliferation rate on plasma-treated aligned and random polycaprolactone (PCL) nanofibrous scaffolds made via an electrospinning technique to attempt periodontal-like tissue in dental implants. Materials and Methods: hPDLSCs were isolated from extracted human premolars and cultured on plasma-treated or untreated PCL-aligned and random scaffolds to enhance adhesion of periodontal ligament (PDL) cells as well as interaction and proliferation. Cell morphology, adhesion, and proliferation rate were evaluated using field emission scanning electron microscopy (FESEM) and the methyl tetrazolium (MTT) assay. The wettability of PCL scaffolds was tested using a goniometer. Results: The hydrophilicity of plasma-treated scaffolds was significantly increased (p ≤ 0.05) in both aligned and random nanofibers compared to the nontreated nanofibrous scaffold. Cells arranged in different directions on the random nanofiber scaffold, while for aligned scaffold nanofibers, the cells were arranged in a pattern that followed the direction of the aligned electrospun nanofibres. The rate of hPDLSC proliferation on an aligned PCL nanofiber scaffold was significantly higher than on a random PCL nanofibrous scaffold with a continuous, well-arranged monolayer of cells, as shown in FESEM. Conclusion: The aligned PCL nanofiber scaffold is superior to random PCL when used as an artificial scaffold for hPDLSC regeneration in PDL tissue engineering applications.

Keywords: dental implant; electrospinning technique; periodontal ligament; poly(caprolactone) nanofibrous; stem cells.

Figure 1

Inverted microscope images for hPDLSCs (scale bars: 1000 µm): (A) 6 days, (B) 15 days, and (C) 22 days. hPDLSCs, human periodontal ligament stem cells.

Figure 2

Periostin interaction with hPDLSCs under fluorescence microscopy at 20x (scale bars: 500 µm). (A) Negative expression. (B) Positive green expression. hPDLSCs, human periodontal ligament stem cells.

Figure 3

Inverted microscope images for hPDLSCs (P0) at 10x and 20x (scale bars 1000 µm): (A) day 15 and (B) day 22. hPDLSCs, human periodontal ligament stem cells.

Figure 4

Inverted microscope images of (A) a random scaffold, (B) an aligned scaffold (scale bars 1000 µm), and (C) contact angle (°) for random and aligned scaffolds before and after plasma treatment. ⁣^∗∗∗P = 0.0001. ns, not significant.

Figure 5

Inverted microscope images (scale bars 1000 µm): (A) of seeded random PCL scaffold with higher cell proliferation in the time intervals, (B) of seeded aligned PCL scaffold with progressed proliferation of the cells in time intervals, and (C) proliferation rate on random and aligned scaffolds during a 3-day cell culture period. PCL, polycaprolactone. ⁣^∗P = 0.0143. ⁣^∗∗P = 0.0017. ⁣^∗∗∗P = 0.0002.

Figure 6

FESEM image of seeded scaffolds at 22 days. (A) Seeded random PCL scaffolds with low growth rates (scale bars: 10 µm). (B) Seeded aligned PCL scaffolds with high growth rates form a monolayer over the whole surface (scale bars: 20 µm). FESEM, field emission scanning electron microscopy; PCL, polycaprolactone.