Synergistic effects of copper-vitamin C incorporated alumina nanocomposite hydrogels for burn wound healing

https://kent-islandora.s3.us-east-2.amazonaws.com/node/14389/83897-thumbnail.jpgThe number of antibiotic-resistant bacterial strains has been dramatically increased over the past few decades[1]. With bacteria constantly evolving, humans are unable to discover new antibiotics fast enough to keep an upper hand in this race[2]. It is therefore vital to explore novel non-antibiotic-based antimicrobial drugs with high efficacy and different mechanisms of action to inhibit bacterial growth. This study was focused on designing a biocompatible and efficient nanocomposite drug delivery system containing Vitamin C-Copper nanoparticles (CuNPs) incorporated into alumina hydrogels. It has been demonstrated that γ-alumina hydrogels with CuNPs embedded in the hydrogel network can be readily formed by hydrolysis reactions of aluminum isopropoxide in water, followed by incorporation of CuNPs. The products obtained in both nanoparticles and composite forms were fully characterized by dynamic light scattering (DLS), X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and Transmission electron microscopy (TEM). The CuNPs released from the hydrogels are expected to exhibit improved cellular penetration via endocytosis and could trigger apoptosis by generating Reactive oxygen species (ROS) in bacterial cells. The antibacterial efficacy of CuNPs was examined and found to be highly active against Staphylococcus aureus (SA), Pseudomonas aeruginosa (PA) as well as methicillin-resistant Staphylococcus aureus (MRSA) and Multi drug-resistant Pseudomonas aeruginosa (MDRPA). References: Kaushik, Neha, Nizam Uddin, Geon Bo Sim, Young June Hong, Ku Youn Baik, Chung Hyeok Kim, Su Jae Lee, Nagendra Kumar Kaushik, and Eun Ha Choi. "Responses of solid tumor cells in DMEM to reactive oxygen species generated by non-thermal plasma and chemically induced ROS systems." Scientific reports 5 (2015): 8587. Usman, M. S., El Zowalaty, M. E., Shameli, K., Zainuddin, N., Salama, M., &amp; Ibrahim, N. A. (2013). Synthesis, characterization, and antimicrobial properties of copper nanoparticles. International journal of nanomedicine, 8, 4467. </ol

Mechanochemical Synthesis of Nanoparticles for Potential Antimicrobial Applications

There is an increased interest in porous materials due to their unique properties such as high surface area, enhanced catalytic properties, and biological applications. Various solvent-based approaches have been already used to synthesize porous materials. However, the use of large volume of solvents, their toxicity, and time-consuming synthesis make this process less effective, at least in terms of principles of green chemistry. Mechanochemical synthesis is one of the effective eco-friendly alternatives to the conventional synthesis. It adopts the efficient mixing of reactants using ball milling without or with a very small volume of solvents, gives smaller size nanoparticles (NPs) and larger surface area, and facilitates their functionalization, which is highly beneficial for antimicrobial applications. A large variety of nanomaterials for different applications have already been synthesized by this method. This review emphasizes the comparison between the solvent-based and mechanochemical methods for the synthesis of mainly inorganic NPs for potential antimicrobial applications, although some metal-organic framework NPs are briefly presented too

Development of Biocompatible Ga₂(HPO₄)₃ Nanoparticles as an Antimicrobial Agent with Improved Ga Resistance Development Profile against <i>Pseudomonas aeruginosa</i>

Ga(III) can mimic Fe(III) in the biological system due to its similarities in charge and ionic radius to those of Fe(III) and can exhibit antimicrobial activity by disrupting the acquisition and metabolism of Fe in bacterial cells. For example, Ga(NO3)3 has been proven to be effective in treating chronic lung infections by Pseudomonas aeruginosa (P. aeruginosa) in cystic fibrosis patients in a recent phase II clinical trial. However, Ga(NO3)3 is an ionic compound that can hydrolyze to form insoluble hydroxides at physiological pH, which not only reduces its bioavailability but also causes potential renal toxicity when it is used as a systemic drug. Although complexion with suitable chelating agents has offered a varying degree of success in alleviating the hydrolysis of Ga(III), the use of nanotechnology to deliver this metallic ion should constitute an ultimate solution to all the above-mentioned problems. Thus far, the development of Ga-based nanomaterials as metalloantibiotics is an underexploited area of research. We have developed two different synthetic routes for the preparation of biocompatible Ga2(HPO4)3 NPs and shown that both the PVP- or PEG-coated Ga2(HPO4)3 NPs exhibit potent antimicrobial activity against P. aeruginosa. More importantly, such polymer-coated NPs do not show any sign of Ga-resistant phenotype development after 30 passes, in sharp contrast to Ga(NO3)3, which can rapidly develop Ga-resistant phenotypes of P. aeruginosa, indicating the potential of using Ga2(HPO4)3 NPs a new antimicrobial agent in place of Ga(NO3)3

Broad-Spectrum Antimicrobial Activity of Ultrafine (BiO)₂CO₃ NPs Functionalized with PVP That Can Overcome the Resistance to Ciprofloxacin, AgNPs and Meropenem in <i>Pseudomonas aeruginosa</i>

Although it has no known biochemical role in living organisms, bismuth has been used to treat syphilis, diarrhea, gastritis and colitis for almost a century due to its nontoxic nature to mammalian cells. When prepared via a top-down sonication route from a bulk sample, bismuth subcarbonate (BiO)2CO3 nanoparticles (NPs) with an average size of 5.35 ± 0.82 nm exhibit broad-spectrum potent antibacterial activity against both the gram-positive and gram-negative bacteria including methicillin-susceptible Staphylococcus aureus (DSSA), methicillin-resistant Staphylococcus aureus (MRSA), drug-susceptible Pseudomonas aeruginosa (DSPA) and multidrug-resistant Pseudomonas aeruginosa (DRPA). Specifically, the minimum inhibitory concentrations (MICs) are 2.0 µg/mL against DSSA and MRSA and 0.75 µg/mL against DSPA and DRPA. In sharp contrast to ciprofloxacin, AgNPs and meropenem, (BiO)2CO3 NPs show no sign of developing Bi-resistant phenotypes after 30 consecutive passages. On the other hand, such NPs can readily overcome the resistance to ciprofloxacin, AgNPs and meropenem in DSPA. Finally, the combination of (BiO)2CO3 NPs and meropenem shows a synergistic effect with the fractional inhibitory concentration (FIC) index of 0.45