Graphene oxide-incorporated PLGA/RGD peptide nanofiber matrices for enhanced neuronal differentiation of mouse hippocampal (HT-22) cells

Abstract

Event Abstract Back to Event Graphene oxide-incorporated PLGA/RGD peptide nanofiber matrices for enhanced neuronal differentiation of mouse hippocampal (HT-22) cells Yong Cheol Shin1, Jong Ho Lee1, Sung Eun Kim1, Jin Su Kim1, Suck Won Hong1, Jin-Woo Oh2 and Dong-Wook Han1 1 Pusan National University, Department of Cogno-Mechatronics Engineering, Korea 2 Pusan National University, Department of Nanoenergy Engineering, Korea During the last decade, there have been many efforts to develop biomimetic scaffolds for promoting nerve tissue regeneration. Herein, graphene oxide (GO)-incorporated nanofiber matrices composed of poly(lactic-co-glycolic acid, PLGA) and RGD peptide nanofibers (GO- PLGA/RGD nanofiber matrices) were fabricated by electrospinning. PLGA is one of the extensively used biodegradable polymer due to its outstanding biocompatibility, good solubility in organic solvents and suitable physicochemical properties for biomimetic scaffolds[1]. RGD peptide, a tripeptide (Arg-Gly-Asp) found within fibronectin, is a recognition motif for integrin that plays an important role in the cell adhesion. The RGD peptides were successfully hybridized with PLGA by using RGD peptide-displaying M13 phages. The M13 phage is a bacterial virus with a nanofiber-like structure and non-toxic to human and mammalian cell. In addition, desired proteins can be displayed on the surface of M13 phage by genetic engineering[2]. Therefore, RGD peptide-displaying M13 phages were used to fabricate the PLGA/RGD nanofiber matrices. Additionally, GO was incorporated into the PLGA/RGD nanofiber for promoting neuronal differentiation. GO is oxidized graphene and has excellent biocompatibility. In particular, it has been reported that the GO can stimulate the differentiation of neural stem cells, as well as various types of cells[3]. We characterized the GO-PLGA/RGD nanofiber matrices by scanning electron microscopy (SEM), Fourier-transform infrared (FT-IR) spectroscopy and contact angle measurement. The SEM images showed that the GO-PLGA/RGD nanofiber matrices have an analogous structure to the natural extracellular matrix. The FT-IR spectra of the matrices revealed that the GO and RGD were uniformly distributed in the GO-PLGA/RGD nanofiber matrices. Additionally, the surface hydrophilicity of the matrices was increased by adding RGD peptide and GO. In addition, the HT-22 cell behaviors including initial adhesion, proliferation and differentiation on the matrices were evaluated. The initial adhesion and proliferation of HT-22 cells were significantly enhanced on the GO-PLGA/RGD nanofiber matrices. Moreover, on the GO-PLGA/RGD nanofiber matrices, the neuronal differentiation of HT-22 cells was stimulated and promoted, which corroborated by immunofluorescence staining for the neurofilaments. These results can be attributed to the incorporation of GO and RGD peptides. The RGD peptide on the matrices enhanced the initial adhesion and proliferation and GO stimulated the neuronal differentiation of HT-22 cells. Therefore, it is proved that the GO-PLGA/RGD nanofiber matrices are suitable tissue engineering scaffolds for promoting not only initial adhesion and proliferation but also the neuronal differentiation of HT-22 cells. Our results demonstrate that the GO-PLGA/RGD nanofiber matrices are remarkably biocompatible and can effectively promote neuronal differentiation of HT-22 cells. In conclusion, it is suggested that the GO-PLGA/RGD nanofiber matrices can be employed as biomimetic scaffolds for nerve tissue engineering and regeneration. This study was supported by grants of the Korea Health Technology R&D Project through the Korea Health Industry Development Institute, funded by the Ministry of Health & Welfare, Republic of Korea (No. HI14C0522)