Design and Synthesis of Copper Nanobiomaterials with Antimicrobial Properties

Abstract

In this work, nanostructured copper materials have been designed, synthetized, and evaluated in order to produce a more efficient and sustainable copper bionanohybrid with catalytical and antimicrobial properties. Thus, conditions are sought where the most critical steps are reduced or minimized, such as the use of reducing agents or the cryogenization step. In addition, the new materials have been characterized through different techniques, and their oxidative and reductive capacities, as well as their antimicrobial activity, have been evaluated. The addition of different quantities of a reducing agent in the synthesis method generated copper bionanohybrids with different metallic species, nanoparticles sizes, and structures. The antimicrobial properties of the bionanohybrids were studied against different strains of Gram-positive and Gram-negative bacteria through two different methods: by counting the CFU and via the disk diffusion test, respectively. The bionanohybrids have demonstrated that different efficiencies depending on the bacterial strain were confronted with. The Cu-PHOS-100% R hybrids with the highest percentage of reduction showed the best antimicrobial efficiency against Escherichia coli and Klebsiella pneumoniae bacteria (>96 or >77% in 4 h, respectively) compared to 31% bacteria reduction using Cu-PHOS-0% R. Also, the antimicrobial activity against Bacillus subtilis materials was obtained with Cu-PHOS-100% R (31 mm inhibition zone and 125 μg/mL minimum inhibitory concentration value). Interestingly, the better antimicrobial activity of the nanobiohybrids against Gram-positive bacteria Mycobacterium smegmatis was obtained with some with a lower reduction step in the synthesis, Cu-PHOS-10% R or Cu-PHOS-20% R (>94% bacterial reduction in 4 h).

Recent Advances on the Design and Applications of Antimicrobial Nanomaterials

“…In addition, the use of a protein allows for the control of the size and shape of the metal nanoparticles produced, as well as the ability to produce them in a monodisperse way (Figure 2). However, a recent study conducted by our group also demonstrated the effect of include a reduction step in the synthesis process of nanobiohybrids, where depending on However, a recent study conducted by our group also demonstrated the effect of include a reduction step in the synthesis process of nanobiohybrids, where depending on the amount of reducing agent added, changes in metal structure are achieved as well as different antimicrobial efficiencies [48]. In the synthesis method, copper sulphate as the metal salt, lipase from Candida antarctica (CAL-B) as the scaffold enzyme, and sodium borohydride as the reducing agent were used.…”

“…In addition, an increase in the reducing agent generated larger and agglomerated nanobiohybrids (Figure 3). the amount of reducing agent added, changes in metal structure are achieved as well as different antimicrobial efficiencies [48]. In the synthesis method, copper sulphate as the metal salt, lipase from Candida antarctica (CAL-B) as the scaffold enzyme, and sodium borohydride as the reducing agent were used.…”

“…Another way in which copper nanoparticles can be used as antimicrobial agents is through their functionalisation with proteins, as mentioned above. In our study described in Section 2.1 [48], copper nanoparticles were synthetised with a lipase protein and different amounts of reducing agent to obtain the best antimicrobial performance against Escherichia coli, Klebsiella pneumoniae, and Mycobacterium smegmatis. The results revealed the differences in the antimicrobial efficacy of the different nanostructured materials.…”

In situ copper-ion catalyzed synthesis of copper containing poly(isocyanurate-urea) xerogels with antibacterial activity and biocompatibility for biomedical applications

“…This redox activity can potentially damage bacteria and generate highly reactive hydroxyl radicals and other reactive oxygen species. 64,65 These radicals can cause detrimental reactions, including destabilization of the cell wall and oxidation of proteins and lipids, thereby contributing to the antibacterial effect. 66 Furthermore, copper ions can disrupt bacterial cell function by replacing and/or binding with native cofactors in metalloproteins.…”

Preparation of Dual‐activity Enzyme‐metal‐nanoparticles Conjugate Catalysts for Cascade Processes

“…[21] This technology has been successfully applied until now in different areas, bioremediation of organic pollutants, [24] fine chemistry [20,23,25] or even as novel antiviral and antimicrobial material formation. [26][27] Some of these results are the most relevant in the literature in the particular catalytic process, demonstrating the advantages to use nanotechnology vs bulk materials, besides the simple synthetic approach of them. The conservation of both activities, producing bifunctional (enzyme and metal) catalysts have been recently successfully used in complex chemical routes by cascade processes in very sustainable conditions, [28][29][30][31][32][33][34][35][36] and some of them will be discussed in this article (Figure 1).…”