Novel metal-polyol-based antibacterial agents
Introduction
Resistance of pathogenic bacteria against antibiotics has become a major medical and pharmaceutical issue. Overuse of antibiotics has been identified as a main cause of pathogenic adaptation of bacteria. Numerous outbreaks of infectious diseases have been reported as a direct effect of antibiotic resistance (Levy, 1998), which still remains a major challenge to be addressed (Cragg & Newman, 2013). Metals are known as metabolism disturbing agents, some of them being harmful for animals and human (Martin & Griswold, 2009). Certain zero-valence metals (metal-zero) such as silver in high dispersion state have long been used in treating skin bacterial infections (Rai, Yadav, & Gade, 2009). Nanoparticles of gold, zinc and titanium have showed high bioactivity. In this context, silver (Ag) and copper (Cu) are also promising nanoparticles that have shown broad-spectrum activity against many species of Gram positive and Gram-negative bacteria (Carretero, 2002; Čı́k, Bujdáková, & Šeršeň, 2001; Čík et al., 2006; Costa, Conte, Buonocore, & Del Nobile, 2011; Dizman, Badger, Elasri, & Mathias, 2007; Gupta, Maynes, & Silver, 1998; Herrera, Burghardt, & Phillips, 2000).
Higher performant antibacterial activity is obtained if Ag and Cu nanoparticles are finely and uniformly sized (España, Sarkar, Biswas, Rusmin, & Naidu, 2019). When highly dispersed, metal nanoparticles (MNP) can be active against pathogenic bacteria without inducing bacterial resistance (España et al., 2019). However, MNPs have a strong tendency to aggregate into bulky inactive clusters (Rees, Zhou, & Compton, 2011). Polyhydroxylated compounds and polyamines bear specific chemical groups that confer them chelating and stabilizing properties for metals (Crooks, Zhao, Sun, Chechik, & Yeung, 2001). Functionalized polymers could exhibit higher effectiveness when supported on solid surfaces (Hellmann et al., 1998). The resulting inorganic-organic matrices hosting metal nanoparticles (Scheme 1) are a novel class of antibacterial agents displaying high surface-to-volume ratio, chemical stability, thermal resistance, non-toxicity and recyclability (Bragg & Rainnie, 1974). Their synthesis has become the main target of the present research.