Graphene Oxide-Incorporated Polylactic Acid/Polyamidoamine Dendrimer Electroconductive Nanocomposite as a Promising Scaffold for Guided Tissue Regeneration

Abstract

In the recent years, electroconductive scaffolds have shown promising capabilities in guided regeneration of electroactive tissues including nerve, heart muscle, bone, cartilage, and skin. Herein, the fabrication of a novel electroconductive poly (L-lactic acid) (PLLA)/polyamidoamine (PAMAM) dendrimer nanofibrous scaffold containing graphene oxide (GO) nanosheets is described. The presence of PAMAM with amine terminal groups successfully aminolyzed PLLA. Interestingly, both PAMAM (5% w/w) and GO (0.5, 1, 2% w/w) not only contributed to reducing the fiber diameter, increasing the hydrophilicity and degradation rate, but also provided a nanocomposite scaffold with enhancement in electrical conductivity. By incorporating 1% w/w of GO, the nanocomposite scaffold exhibited optimized properties, including electrical conductivity (≈3.09 × 10⁻⁵ S m⁻¹), crystallinity (≈ 47%), Young's modulus (≈16.95 MPa), as well as strength (≈1.58 MPa). This nanocomposite also demonstrated significant antibacterial activity of ≥ 90% against both gram-positive and gram-negative bacteria. Cellular assays confirmed acceptable cytocompatibility of the nanocomposite scaffolds containing GO and PAMAM, which can support the viability and proliferation of PC-12 cells. In conclusion, the presence of GO nanosheets alongside PAMAM dendrimers can synergically promote the properties of the prepared nanofibrous mats which can be used as potential electroconductive scaffolds for guided tissue regeneration.