Dual Functions of Highly Potent Graphene Derivative–Poly-l-Lysine Composites To Inhibit Bacteria and Support Human Cells

Abstract

Dual-function poly(L-lysine) (PLL) composites that function as antibacterial agents and promote the growth of human cell culture have been sought by researchers for a long period. In this paper, we report the preparation of new graphene derivative-PLL composites via electrostatic interactions and covalent bonding between graphene derivatives and PLL. The resulting composites were characterized by infrared spectroscopy, scanning electron microscopy, and X-ray photoelectron spectroscopy. The novel dual function of PLL composites, specifically antibacterial activity and biocompatibility with human cells [human adipose-derived stem cells and non-small-cell lung carcinoma cells (A549)], was carefully investigated. Graphene-DS-PLL composites composed of 4-carboxylic acid benzene diazonium salt (DS) generated more anionic carboxylic acid groups to bind to cationic PLLs, forming the most potent antibacterial agent among PLL and PLL composites with high biocompatibility with human cell culture. This dual functionality can be used to inhibit bacterial growth while enhancing human cell growth.

Is Graphene a Promising Nano-Material for Promoting Surface Modification of Implants or Scaffold Materials in Bone Tissue Engineering?

“…12 For ASCs, Some et al reported that a graphene derivative-PLL composite had more than double the ability to proliferate ASCs compared with PLL alone, indicating that these materials are not cytotoxic for the cells. 87 In addition, the GO film and rGOchitosan substrata (5%) proved to be a suitable environment for the time-dependent viability of ASCs and BMMSCs. 6,10 In addition, the proliferation of osteoblasts or preosteoblasts on graphene-related materials, including rGO, GO/graphene-hydroxyapatite, chitosan-graphene oxide (CS-GO), and Nylon 6,6-GO, was enhanced.…”

“…6 In addition, Some et al discovered that ASCs attached at higher levels to graphene derivative-poly (L-lysine) (PLL) composite-coated coverslips compared with coverslips coated with only GO or PLL. 87 In another study by Kim and his colleagues, rGOchitosan substrata were fabricated after spin coating of rGO-chitosan composites on bare glass. They found that rGO-chitosan substrata, regardless of the incorporated graphene concentration, provided a suitable environment for hMSC adhesion: hMSCs on the rGO-chitosan substrata showed a large number of FAs and enhanced expression of the integrin b 1 .…”

“…54 Some et al and Misra and Chaudhari assumed that the higher surface area might be the cause of higher adhesion and proliferation. 53,87 Nayak et al thought that the ripples and wrinkles might play a role in protein adsorption, cell adhesion, proliferation, and differentiation. 4 Recent studies suggest that nanostructured and microrough topographies might also mediate osteogenic differentiation.…”

Graphene Oxide Reinforced Polycarbonate Nanocomposite Films with Antibacterial Properties

“…The inhibition zone was clearly identified at the edges of the samples, where the bacteria have not grown enough to be visible. A possible mechanism could be the following: the GO came into contact with the bacteria; it initiates the oxidation of glutathione (prominent cellular antioxidant) and the GO also acts as conducting bridge for extracting electrons from the glutathione and delivering them to the environment [4,11,38]. Notably, the pristine PC sample did not show any inhibition zones, due to the absence of GO.…”

“…Recently, the GOs have been validated as a potential candidate for killing Gram-negative (E. coli) and Grampositive (S. aureus) bacteria [4,7,[11][12][13][14][15]. Owing to their excellent antibacterial nature, the reinforcement of the GOs in a polymer matrix not only enhances the antibacterial nature of the pristine polymer but also improves the mechanical, thermal, and chemical stabilities significantly [16,17].…”