Abstract
Recent studies have indicated that graphene and its derivative graphene oxide (GO) engage in a wide range of antibacterial activities with limited toxicity to human cells. Here, we systematically evaluate the dependence of GO toxicity on the size of the nanoparticles used in treatments: we compare the cytotoxic effects of graphene quantum dots (GQDs, <15 nm), small GOs (SGOs, 50–200 nm), and large GOs (LGOs, 0.5–3 μm). We synthesize the results of bacterial colony count assays and SEM-based observations of morphological changes to assess the antibacterial properties that these GOs bring into effect againstE. coli. We also use Live/Dead assays and morphological analysis to investigate changes to mammalian (Murine macrophage-like Raw 264.7) cells induced by the presence of the various GO particle types. Our results demonstrate that LGOs, SGOs, and GQDs possess antibacterial activities and cause mammalian cell cytotoxicity at descending levels of potency. Placing our observations in the context of previous simulation results, we suggest that both the lateral size and surface area of GO particles contribute to cytotoxic effects. We hope that the size dependence elucidated here provides a useful schematic for tuning GO-cell interactions in biomedical applications.
Highlights
Carbon-based nanomaterials (CBNs) exhibit a congruent combination of chemical and physical properties that make them promising candidate materials for biomedical application [1]
We here attempt to shed light on a simple question related to GO-cell interactions: how does the size of a GO-based nanomaterial impact its cytotoxicity in specific systems? To systematically study the dependence of GO-induced antimicrobial and mammalian cytotoxicity on particle size, we report the effects of graphene quantum dots (GQDs), small graphene oxide nanosheets (SGOs), and large graphene oxide nanosheets (LGOs) on E. coli and murine macrophage-like cells
Contrast among the lateral dimensions of the materials used in our experiments was high (Figures 1(a)– 1(c)): Graphene quantum dots (GQDs) were comparatively small (
Summary
Carbon-based nanomaterials (CBNs) exhibit a congruent combination of chemical and physical properties that make them promising candidate materials for biomedical application [1]. Carbon nanotubes (CNTs) have been explored in a wide array of diagnostic and therapeutic contexts, showing promise in areas like drug delivery, biomedical imaging, and biosensing [2]. Graphene oxide, or graphene-based materials have been extensively explored as either active agents or drug delivery systems [6] in anticancer [7], antimicrobial [8], and anti-Alzheimer’s disease [9] therapies. These intriguing applications of graphenebased nanomedicine have been checked by secondary toxicity caused by poor biocompatibility, high agglomeration propensities, and a lack of selectivity toward targeting diseased cells [10]
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