Surface-modified electrospun poly(epsilon-caprolactone) scaffold with improved optical transparency and bioactivity for damaged ocular surface reconstruction.

Purpose: The purpose of this study was to modify and functionalize the surface of synthetic poly-ε-caprolactone (PCL) nanofibrous scaffolds to improve their biocompatibility in order to provide better "cell-substrate" interaction.

Methods: Poly-ε-caprolactone solution was electrospun and its surface functionality was modified by helium-oxygen (He/O2) plasma discharge. Scaffolds were characterized for their morphology, wetting ability, mechanical strength, and optical properties by using scanning electron microscopy (SEM), water contact angle measurement, tensile strength, and ultraviolet-visible (UV-Vis) spectrophotometer, respectively. The biocompatibility of nanofibers was explored by culturing human corneal epithelial (HCE-T) cell line. Subsequently, human limbal epithelial cells (LECs) were cultured to evaluate the bioactivity. Cell proliferation was checked by MTT (3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. Immunofluorescent staining and reverse transcription-polymerase chain reaction were done to check the gene expression; SEM was used to study the morphology.

Results: Plasma-treated and untreated scaffolds showed almost similar morphology and tensile strength. Water contact angle measurement and optical transparency data showed that the plasma-treated PCL (pPCL) exhibited significantly improved wettability and transparency as compared to the untreated PCL scaffolds. Biocompatibility results indicated that both scaffolds are biocompatible in terms of cell survival and proliferation. However, pPCL showed better cell adhesion and proliferation. Results supported that LEC cultured on pPCL scaffolds had enhanced cell adhesion and proliferation, in comparison to untreated PCL. Gene expression study showed cultures were able to retain their normal phenotype on both scaffolds.

Conclusions: The hydrophilicity of the surface achieved by plasma treatment effectively enhanced the transparency and promoted the biocompatibility of scaffolds. These nanofibers may act as biological cues for endorsing ocular surface engineering.