Properties of Silver and Copper Nanoparticle Containing Aqueous Suspensions and Evaluation of their <i>In Vitro </i>Activity against <i>Candida albicans </i>and <i>Staphylococcus aureus </i>Biofilms

Abstract

Most microorganisms grow on surfaces as biofilms rather than as individual planktonic cells, and cells within biofilms show high levels of resistance against antimicrobial drugs. Thereby biofilm formation complicates treatment and contributes to high morbidity and mortality rates associated with infections. This study explores the physical, optical, and nano-structural properties of silver and copper nanoparticles dispersed in aqueous suspensions (nanoparticulate colloidal water) and examines their in vitro activity against microbial biofilms. Silver and copper nanoparticulate colloidal water of various concentrations were prepared and studied. Their surface energies, surface charge and surface plasmonic resonance properties were determined using contact angle measurement, zeta potential measurement and optical spectrometry, respectively. A model of biofilm formation on the wells of microtiter plates was used to determine the activity of the nanoparticulate suspensions against fungal and bacterial biofilms. Scanning electron microscopy (SEM) was used to observe the nanoparticle interactions with microbial cells within the biofilms. Results show that silver nanoparticle-containing liquids have higher surface energy than their copper counterparts; and that the surface energy increases as the concentration of silver nanoparticles increases. Altogether, the effectiveness of silver nanoparticle colloidal suspensions in controlling biofilm formation is observed and reported. For a given size of silver nanoparticles studied, it is found that the effective concentrations against microbial biofilms are far lower than their cytotoxic concentrations, indicating an overall safety and a good therapeutic index thus substantial application potential.

Comparative environmental fate and toxicity of copper nanomaterials

“…Cu + 2 can also be synthesized as Cu(OH) 2 NPs. In general, the toxicity of copper compounds has been exploited to protect agricultural crops from many pests, including those causing fungal infections (Montes et al, 2015;Kalatehjari et al, 2015;Bramhanwade et al, 2016;Epstein and Bassein, 2001;Begum et al, 2015;Fan et al, 2011;El-Habbaa et al, 2016;Wightwick et al, 2008;Stansly and Kostyk, 2015;Thind and Singh, 2015;Ferreira et al, 2007), and copper pesticides are now applied on some "organic" crops (Baker et al, 2002;Winter and Davis, 2006). Their use as an antimicrobial agent has also been considered in several applications (Emam et al, 2014;Shebl, 2014;Mjos et al, 2016;Congrádyová et al, 2014).…”

“…It is estimated that only a few hundred tons of the total production were converted to Cu-based nanoparticles (Cu NPs) , despite there being many emerging applications for nano-Cu materials. Many applications involve the traditional role of Cu as a conductor, such as conductive dyes (Albrecht et al, 2016;Hokita et al, 2015;Tam and Ng, 2015;Kharisov and Kharissova, 2010;Tsai et al, 2015;Gopalan et al, 2016) or heat transfer fluids (Park et al, 2015;Montes et al, 2015;Azizi et al, 2016;Rizwan-ul-Haq et al, 2016), but the use of nano-Cu is rapidly expanding into novel applications such as catalysts in organic synthesis (Dugal and Mascarenhas, 2015;Lennox et al, 2016;Barot et al, 2016), sensors (Albrecht et al, 2016;Tsai et al, 2015;Gopalan et al, 2016;Brahman et al, 2016;Pourbeyram and Mehdizadeh, 2016), solar cells (Yoon et al, 2010;Parveen et al, 2016;Shen et al, 2016), light-emitting diodes , hydrogen generation (Liu et al, 2015a;Liu et al, 2015b), and drug delivery (Woźniak-Budych et al, 2016). Based on the antifungal and antimicrobial properties of Cu + 2 , Cu NPs are actively being developed for applications in agriculture and food preservation (Park et al, 2015;Montes et al, 2015;Dugal and Mascarenhas, 2015;Ray et al, 2015;Kalatehjari et al, 2015;Ponmurugan et al, 2016;Maniprasad et al, 2015;Majumder and Neogi, 2016;Villanueva et al, 2016), textiles …”

Nanotechnology as an Alternative to Reduce the Spread of COVID-19

“…Also, it is not uncommon for patients with COVID-19 to suffer from complications of acute organ injury and secondary infection [52]. Nanomaterials display a broad range of antimicrobial activity against bacteria [53,54], protozoa [55,56], and fungi [57][58][59][60]. In healthcare-related facilities, nanotechnologybased sanitizers could simultaneously reduce the presence of viruses and opportunistic microorganisms.…”

A Review on Effect of Copper and Iron Nanoparticle on Agricultural Crop

“…Application of Cu-NPs leads to increased lignification in the pericarp cell walls of the fruit due to which the firmness of tomato fruits is increased. In particular nano Cu based materials are positively developed specifically for applications in agricultural and food preservation based on the antifungal and antimicrobial properties of Cu +2 (Montes et al 2015;Majumder and Neogi, 2016), and nanopesticides are based on Cu-NPs (Keller et al 2017).…”