Graphene oxide in zinc alginate films: Antibacterial activity, cytotoxicity, zinc release, water sorption/diffusion, wettability and opacity

Abstract

Alginate is considered an exceptional biomaterial due to its hydrophilicity, biocompatibility, biodegradability, nontoxicity and low-cost in comparison with other biopolymers. We have recently demonstrated that the incorporation of 1% graphene oxide (GO) into alginate films crosslinked with Ca 2+ cations provides antibacterial activity against Staphylococcus aureus and methicillin-resistant Staphylococcus epidermidis , and no cytotoxicity for human keratinocyte HaCaT cells. However, many other reports in literature have shown controversial results about the toxicity of GO demanding further investigation. Furthermore, the synergic effect of GO with other divalent cations with intrinsic antibacterial and cytotoxic activity such as Zn 2+ has not been explored yet. Thus, here, two commercially available sodium alginates were characterised and utilized in the synthesis of zinc alginate films with GO following the same chemical route reported for the calcium alginate/GO composites. The results of this study showed that zinc release, water sorption/diffusion and wettability depended significantly on the type of alginate utilized. Furthermore, Zn 2+ and GO produced alginate films with increased water diffusion, wettability and opacity. However, neither the combination of GO with Zn 2+ nor the use of different types of sodium alginates modified the antibacterial activity and cytotoxicity of the zinc alginates against these Gram-positive pathogens and human cells respectively.

Preparation, Characterization and Properties of Porous PLA/PEG/Curcumin Composite Nanofibers for Antibacterial Application

“…It could be seen that the antibacterial effect of the PEG/PLA CNFMs with a weight ratio of 1:7 was poor, and the inhibition rates of the PLA/PEG/Cur CNFMs were all beyond 97%. The antibacterial effect of the PLA/PEG/Cur CNFMs was as good as that of other antibacterial materials in Reference [26]. However, the inhibition rates decreased as the PLA weight ratio increased.…”

Physical Properties, Chemical Analysis, and Evaluation of Antimicrobial Response of New Polylactide/Alginate/Copper Composite Materials

“…(e.g., [35][36][37][38][39][40][41][42][43][44]), and also for the removal of heavy metal salts, e.g., copper, lead, and mercury (e.g., [45][46][47][48][49][50]). The role of alginate in antibacterial finishing of textiles has been reviewed recently by Li et al [51].…”

Acrylic-Based Hydrogels as Advanced Biomaterials

“…GO is also a 2D nanomaterial with excellent physical properties [53] like graphene, usually produced from natural graphite that can be easily exfoliated into monolayer sheets. Nevertheless, GO is more utilised than GN in the synthesis of composite materials because it possesses hydrophilic oxygenated functional groups, such as hydroxyl (-OH), epoxy (-C-O-C-), carbonyl (-C=O) and carboxyl (-COOH), which render easier its dispersion in water [54][55][56][57]. Thus, the incorporation of GO nanosheets into poly(acrylic acid)/gelatin composite hydrogels significantly increased their Young's modulus and maximum stress.…”