Limits...
Antimicrobial polymers with metal nanoparticles.

Palza H - Int J Mol Sci (2015)

Bottom Line: Unlike other antimicrobial agents, metals are stable under conditions currently found in the industry allowing their use as additives.Today these metal based additives are found as: particles, ions absorbed/exchanged in different carriers, salts, hybrid structures, etc.The objective of the present review is to show examples of polymer/metal composites designed to have antimicrobial activities, with a special focus on copper and silver metal nanoparticles and their mechanisms.

View Article: PubMed Central - PubMed

Affiliation: Departamento de Ingeniería Química y Biotecnología, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Beauchef 850, Santiago 8320000, Chile. hpalza@ing.uchile.cl.

ABSTRACT
Metals, such as copper and silver, can be extremely toxic to bacteria at exceptionally low concentrations. Because of this biocidal activity, metals have been widely used as antimicrobial agents in a multitude of applications related with agriculture, healthcare, and the industry in general. Unlike other antimicrobial agents, metals are stable under conditions currently found in the industry allowing their use as additives. Today these metal based additives are found as: particles, ions absorbed/exchanged in different carriers, salts, hybrid structures, etc. One recent route to further extend the antimicrobial applications of these metals is by their incorporation as nanoparticles into polymer matrices. These polymer/metal nanocomposites can be prepared by several routes such as in situ synthesis of the nanoparticle within a hydrogel or direct addition of the metal nanofiller into a thermoplastic matrix. The objective of the present review is to show examples of polymer/metal composites designed to have antimicrobial activities, with a special focus on copper and silver metal nanoparticles and their mechanisms.

Show MeSH

Related in: MedlinePlus

A summary of the mechanisms associated with the antimicrobial behaviour of metal nanoparticles: (1) “Trojan-horse effect” due to endocytosis processes; (2) attachment to the membrane surface; (3) catalyzed radical formation; and (4) release of metal ions.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4307351&req=5

ijms-16-02099-f002: A summary of the mechanisms associated with the antimicrobial behaviour of metal nanoparticles: (1) “Trojan-horse effect” due to endocytosis processes; (2) attachment to the membrane surface; (3) catalyzed radical formation; and (4) release of metal ions.

Mentions: Nanoparticles can dissolve faster in a given solution volume as compared with larger particles releasing therefore a higher amount of metal ions [34]. Therefore, based on the mechanisms aforementioned based on the presence of metal ion, nanoparticles should present stronger antimicrobial effects than either microparticles or metal surfaces. For instance, the copper nanoparticle corrosion in distilled water is quite different as compared with microparticles [35]. The Cu2+ transformation ratio of microparticles increases slowly with the immersion time and levels off eventually, meanwhile in nanoparticles this transformation ratio increases sharply with the immersion time, reaching a peak rapidly, and then decreasing increases sharply with the immersion time, reaching a peak rapidly, and then decreasing. However, new toxic mechanisms, depending on the cellular characteristics at the nano-scale, emerge by taking into account the role of the particle size itself [26]. The best example relate with the direct incorporation of nanoparticles into the cell via endocytotic mechanisms. Afterward the cellular uptake of ions increases as ionic species are subsequently released within the cells by nanoparticle dissolution, a process often referred as “the Trojan horse mechanism” [36,37,38]. This high intracellular concentration gained after nanoparticle dissolution within the cell likely results in massive oxidative stress. A summary of the possible mechanisms associated with the antimicrobial behavior of metal nanoparticles are displayed in Figure 2, and will be discussed below in detail.


Antimicrobial polymers with metal nanoparticles.

Palza H - Int J Mol Sci (2015)

A summary of the mechanisms associated with the antimicrobial behaviour of metal nanoparticles: (1) “Trojan-horse effect” due to endocytosis processes; (2) attachment to the membrane surface; (3) catalyzed radical formation; and (4) release of metal ions.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4307351&req=5

ijms-16-02099-f002: A summary of the mechanisms associated with the antimicrobial behaviour of metal nanoparticles: (1) “Trojan-horse effect” due to endocytosis processes; (2) attachment to the membrane surface; (3) catalyzed radical formation; and (4) release of metal ions.
Mentions: Nanoparticles can dissolve faster in a given solution volume as compared with larger particles releasing therefore a higher amount of metal ions [34]. Therefore, based on the mechanisms aforementioned based on the presence of metal ion, nanoparticles should present stronger antimicrobial effects than either microparticles or metal surfaces. For instance, the copper nanoparticle corrosion in distilled water is quite different as compared with microparticles [35]. The Cu2+ transformation ratio of microparticles increases slowly with the immersion time and levels off eventually, meanwhile in nanoparticles this transformation ratio increases sharply with the immersion time, reaching a peak rapidly, and then decreasing increases sharply with the immersion time, reaching a peak rapidly, and then decreasing. However, new toxic mechanisms, depending on the cellular characteristics at the nano-scale, emerge by taking into account the role of the particle size itself [26]. The best example relate with the direct incorporation of nanoparticles into the cell via endocytotic mechanisms. Afterward the cellular uptake of ions increases as ionic species are subsequently released within the cells by nanoparticle dissolution, a process often referred as “the Trojan horse mechanism” [36,37,38]. This high intracellular concentration gained after nanoparticle dissolution within the cell likely results in massive oxidative stress. A summary of the possible mechanisms associated with the antimicrobial behavior of metal nanoparticles are displayed in Figure 2, and will be discussed below in detail.

Bottom Line: Unlike other antimicrobial agents, metals are stable under conditions currently found in the industry allowing their use as additives.Today these metal based additives are found as: particles, ions absorbed/exchanged in different carriers, salts, hybrid structures, etc.The objective of the present review is to show examples of polymer/metal composites designed to have antimicrobial activities, with a special focus on copper and silver metal nanoparticles and their mechanisms.

View Article: PubMed Central - PubMed

Affiliation: Departamento de Ingeniería Química y Biotecnología, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Beauchef 850, Santiago 8320000, Chile. hpalza@ing.uchile.cl.

ABSTRACT
Metals, such as copper and silver, can be extremely toxic to bacteria at exceptionally low concentrations. Because of this biocidal activity, metals have been widely used as antimicrobial agents in a multitude of applications related with agriculture, healthcare, and the industry in general. Unlike other antimicrobial agents, metals are stable under conditions currently found in the industry allowing their use as additives. Today these metal based additives are found as: particles, ions absorbed/exchanged in different carriers, salts, hybrid structures, etc. One recent route to further extend the antimicrobial applications of these metals is by their incorporation as nanoparticles into polymer matrices. These polymer/metal nanocomposites can be prepared by several routes such as in situ synthesis of the nanoparticle within a hydrogel or direct addition of the metal nanofiller into a thermoplastic matrix. The objective of the present review is to show examples of polymer/metal composites designed to have antimicrobial activities, with a special focus on copper and silver metal nanoparticles and their mechanisms.

Show MeSH
Related in: MedlinePlus