Comparative In Vitro Evaluation of Early Cell Responses of Porous and Nonporous Polycaprolactone Electrospun Nanofibrous Membrane for Guided Tissue Regeneration.

OBJECTIVE

The production of porous polycaprolactone (PCL) electrospun fibers has already been reported in the literature. However, most of the studies reported the production of porous fibers on a micrometer scale. Hence, the main aim of this study is to (1) fabricate PCL membranes with secondary nanoporous fibers to improve the attachment, spreading, and proliferation of cells, and subsequent extracellular matrix deposition and (2) evaluate its biocompatibility on different cell types in comparison to a nonporous one.

MATERIALS AND

METHODS

Secondary nanopores were introduced by adjusting humidity and employing a binary solvent system of chloroform and dimethyl sulfoxide. The membranes were characterized using field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD) analysis, and water contact angle. The biological activity on cells was assessed using the XTT assay, cell adhesion and spreading were analyzed by FE-SEM and confocal studies, and gene expression was measured by real-time polymerase chain reaction. Human fetal osteoblasts (hFOBs), human gingival fibroblasts (HGFs), and human umbilical vein endothelial cells (HUVECs) were utilized for cell-biomaterial interaction studies.

STATISTICAL ANALYSIS: Two-way ANOVA (analysis of variance) followed by Tukey's multiple comparison was used to assess the statistical significance.

RESULTS

The FE-SEM analysis revealed an average fiber diameter of 774 ± 193 nm for the porous membrane and 642 ± 176 nm for the nonporous membrane, with secondary nanopores averaging 151 ± 31 nm in length. The XRD analyses confirmed characteristic fingerprint vibrational bands of PCL for both membrane types. Water contact angle measurement showed no significant differences, with porous membranes at 131 ± 2° and nonporous membranes at 122 ± 10°. Both the porous and nonporous membranes displayed comparable cell viability. The porous membranes showed a tendency toward good cell spreading with statistically significant upregulation of type I collagen (COL-I) in hFOBs, and vascular endothelial growth factor (VEGF) expression in HUVECs compared with the nonporous membranes.

CONCLUSION

The cells on porous membranes demonstrated a trend toward improved spreading and functional activity compared with those on nonporous surfaces. However, considering the exploratory nature of this work, and the lack of mechanical and functional tests, it is too early to draw a definitive conclusion on the superiority of porous PCL membranes over nonporous ones.