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.