Bimetallic silver–platinum nanoparticles with combined osteo-promotive and antimicrobial activity

Abstract

Bimetallic alloyed silver-platinum nanoparticles (AgPt NP) with different metal composition from Ag 10 Pt 90 to Ag 90 Pt 10 in steps of 20 mol% were synthesized. The biological effects of AgPt NP, including cellular uptake, cell viability, osteogenic differentiation and osteoclastogenesis as well as the antimicrobial activity towards Staphylococcus aureus and Escherichia coli were analyzed in comparison to pure Ag NP and pure Pt NP. The uptake of NP into human mesenchymal stem cells was confirmed by cross-sectional focused-ion beam preparation and observation by scanning and transmission electron microscopy in combination with energydispersive x-ray analysis. Lower cytotoxicity and antimicrobial activity were observed for AgPt NP compared to pure Ag NP. Thus, an enhanced Ag ion release due to a possible sacrificial anode effect was not achieved. Nevertheless, a Ag content of at least 50 mol% was sufficient to induce bactericidal effects against both Staphylococcus aureus and Escherichia coli. In addition, a Pt-related (50 mol% Pt) osteo-promotive activity on human mesenchymal stem cells was observed by enhanced cell calcification and alkaline phosphatase activity. In contrast, the osteoclastogenesis of rat primary precursor osteoclasts was inhibited. In summary, these results demonstrate a combinatory osteo-promotive and antimicrobial activity of bimetallic Ag 50 Pt 50 NP.

Synthesis, Structure, Properties, and Applications of Bimetallic Nanoparticles of Noble Metals

“…[ 39f,60a,62 ] The presence of platinum in alloyed silver–platinum nanoparticles causes an osteopromotive activity in contact with human mesenchymal stem cells. [ 63 ] Figure shows typical cell‐biological data of bimetallic nanoparticles.…”

Antimicrobial efficacy of platinum‐doped silver nanoparticles

“…Furthermore, alloying with platinum did not enhance the antimicrobial activity of silver nanoparticles. However, it should be noted that platinum concentrations lower than 10 mol% were not investigated in these studies (Breisch et al, 2019; Chang et al, 2019).…”

“…One approach to enhancing the antimicrobial activity of AgNPs while maintaining biocompatible levels is to dope silver nanoparticles with small amounts of a second metal, electrochemically less active than silver, creating a bimetallic nanoparticle (Gu, Zhang, & Tao, 2012). When placed in an electrolytic environment, the silver component of the bimetallic nanoparticle may act as a sacrificial anode and preferentially dissolve, promoting the release of ionic silver (Breisch et al, 2019; Narozny, Zakowski, & Darowicki, 2014). The electrocatalytic reaction occurs more readily when both metals are present at the surface of the particles (Li & Yamauchi, 2013).…”

“…Several studies have examined the combined effects of silver and platinum on antimicrobial efficacy (Breisch et al, 2019; Chang et al, 2019). Chang et al demonstrated that alloying AgNPs with approximately 11 mol% of gold, platinum, or palladium promoted the release of Ag + .…”

“…coli (Chang et al, 2019). In contrast, Breisch et al, studied the antimicrobial activity of bimetallic silver‐platinum nanoparticles with compositions ranging from 10 to 90 mol% platinum (Breisch et al, 2019). The antimicrobial activity was assessed against S .…”