Korean J Dent Mater.  2024 Mar;51(1):29-42. 10.14815/kjdm.2024.51.1.29.

Physicochemical properties and biocompatibility of polypyrrole-coated polycaprolactone nanofibers for guided tissue regeneration

• Kwon T
• Shim H
• Hong MH

• KMID: 2555449
• DOI: http://doi.org/10.14815/kjdm.2024.51.1.29

Abstract

Polycaprolactone (PCL) nanofibers are widely used in the field of tissue regeneration as a biodegradable material. However, there is a limitation in that low hydrophilicity and tissue cannot be directly regenerated. Recent studies have shown that polypyrrole (PPy) has potential in the field of tissue engineering due to its electrical conductivity and biocompatibility. Meanwhile, the electrospinning has the advantage of using most polymers and of facilitating a porous structure suitable for tissue regeneration, so the nanofibers were fabricated through electrospinning. The purpose of this study is to evaluate the physicochemical properties and biocompatibility of PCL nanofibers coated with PPy for guided tissue regeneration. To this end, PCL nanofibers coated with four types of concentration groups were prepared. The group was named according to the concentration ratio of PPy, and the control pure PCL containing no PPy and 20PPy, 30PPy, and 40PPy containing 20 wt%, 30 wt%, and 40 wt%, respectively, consisted of the experimental group. The mixed solution of PCL and pyrrole monomer was electrospun. Then precipitate in an iron (III) chloride (FeCl₃ ) solution as an oxidizing agent which contains pyrrole monomer and polymerized. A tensile test was performed to confirm mechanical properties, and surface hydrophilicity was confirmed through measurement of contact angle. Electrical conductivity was also confirmed through measurement of resistance values. Lastly, cytotoxicity evaluation was performed using fibroblast (L929) and preosteoblast (MC3T3-E1) cell lines to confirm biocompatibility. The results were evaluated as one-way ANOVA (p-value = 0.05), and post-analysis was performed using Tukey’s post-hoc test. PPycoated PCL nanofibers showed no statistically significant decrease in mechanical strength compared to PPy-uncoated PCL nanofibers, while electrical conductivity increased significantly at all concentrations. When 30wt% or more of PPy was coated, hydrophilicity was significantly increased compared to the PPy-uncoated PCL nanofibers. Regardless of the concentration of PPy, cytotoxicity was not shown in all groups. Accordingly, it is expected that the PPy-coated PCL fibers may be applied as a material for guided tissue regeneration. This is because of improved hydrophilicity and electrical conductivity without deteriorated physical properties and cytotoxicity.

Keyword

Dental materials; Guided tissue regeneration; Electrospinning; Polypyrrole; Conductive scaffold