One-Pot Synthesis of Biocompatible Silver Nanoparticle Composites from Cellulose and Keratin: Characterization and Antimicrobial Activity

Abstract

A novel, simple method was developed to synthesize biocompatible composites containing 50% cellulose (CEL) and 50% keratin (KER) and silver in the form of either ionic (Ag + ) or Ag 0 nanoparticles (Ag + NPs or Ag 0 NPs). In this method, butylmethylimmidazolium chloride ([BMIm + Cl -]), a simple ionic liquid, was used as the sole solvent and silver chloride was added to the [BMIm + Cl -] solution of [CEL+KER] during the dissolution process. The silver in the composites can be maintained as ionic silver (Ag + ) or completely converted to metallic silver (Ag 0 ) by reducing it with NaBH4. The results of spectroscopy [Fourier transform infrared and X-ray diffraction (XRD)] and imaging [scanning electron microscopy (SEM)] measurements confirm that CEL and KER remain chemically intact and homogeneously distributed in the composites. Powder XRD and SEM results show that the silver in the [CEL+KER+Ag + ] and [CEL+KER+Ag 0 ] composites is homogeneously distributed throughout the composites in either Ag + (in the form of AgClNPs) or Ag 0 NPs form with sizes of 27 ± 2 or 9 ± 1 nm, respectively. Both composites were found to exhibit excellent antibacterial activity against many bacteria including Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, methicillin-resistant S. aureus (MRSA), and vancomycin-resistant Enterococus faecalis (VRE). The antibacterial activity of both composites increases with the Ag + or Ag 0 content in the composites. More importantly, for the same bacteria and the same silver content, the [CEL+KER+AgClNPs] composite is relatively more toxic than [CEL+KER+Ag 0 NPs] composite. Experimental results confirm that there was hardly any Ag 0 NPs release from the [CEL+KER+Ag 0 NPs] composite, and hence its antimicrobial activity and NOT THE PUBLISHED VERSION; this is the author's final, peer-reviewed manuscript. The published version may be accessed by following the link in the citation at the bottom of the page. Vol 8, No. 50 (2016): pg. 34791-34801. DOI. This article is © American Chemical Society and permission has been granted for this version to appear in e-Publications@Marquette. American Chemical Society does not grant permission for this article to be further copied/distributed or hosted elsewhere without the express permission from American Chemical Society. ACS Applied materials & Interfaces,3 biocompatibility is due not to any released Ag 0 NPs but rather entirely to the Ag 0 NPs embedded in the composite. Both AgClNPs and Ag 0 NPs were found to be toxic to human fibroblasts at higher concentration (>0.72 mmol), and for the same silver content, the [CEL+KER+AgClNPs] composite is relatively more toxic than the [CEL+KER+Ag 0 NPs] composite. As expected, by lowering the Ag 0 NPs concentration to 0.48 mmol or less, the [CEL+KER+Ag 0 NPs] composite can be made biocompatible while still retaining its antimicrobial activity against bacteria such as E. coli, S. aureus, P. aeruginosa, MRSA, and VRE. These results, together with our previous finding that [CEL+KER] composites can ...

Effect of Chemically Engineered Au/Ag Nanorods on the Optical and Mechanical Properties of Keratin Based Films

“…Indeed, several works report the preparation of stable Ag and Au NPs using extracted wool keratin as capping agent (Lü and Cui, 2010;Shanmugasundaram and Ramkumar, 2018), in order to combine their antibacterial properties for wound-healing applications. Diversely, only few reports are focused on the preparation of keratin-plasmonic NPs composites films (Tran et al, 2016(Tran et al, , 2018 and on their potential application in electronic devices. All these works confirm how the combination of polymeric matrices such as proteins with inorganic nanoparticles can allow the addition of specific and tunable functionalities (optical, magnetic and electrical properties, etc).…”

Facile synthesis, structure, biocompatibility and antimicrobial property of gold nanoparticle composites from cellulose and keratin

“…In fact, by use of [BMIm + Cl − ] as the sole solvent, we have recently developed a novel method to synthesize composites containing CEL, KER and silver in the form of either ionic (Ag + ) or Ag 0 nanoparticles (Ag + NPs or Ag 0 NPs). 18 The [CEL+KER+Ag 0 NPs] composite was found to inhibit growth of various bacteria. Unfortunately, both [CEL+KER+Ag + NPs] and [CEL+KER+Ag 0 NPs] composites were cytotoxic to human fibroblasts.…”

“…Unfortunately, both [CEL+KER+Ag + NPs] and [CEL+KER+Ag 0 NPs] composites were cytotoxic to human fibroblasts. 18 However, [CEL+KER+Ag 0 NPs] composite was biocompatible when its Ag 0 NPs concentration was at or below 0.48 mmol. 18 It is, therefore, tempting to use this synthetic method to synthesize [CEL+KER] composite which contains gold nanoparticles.…”

Antimicrobial Effectiveness of Rinse-Free Hospital Bathing Cleansers after 24 h of Initial Exposure to Common Pathogenic Micro-Organisms

“…The efficacy against MRSA is substantiated in the literature by Ansari, where they used confocal laser scanning techniques to examine anti-biofilm activity of a silver nano particle coating for medical devices [16]. However, not all products enhanced with silver result in the same benefit; for example with VRE we see a growth reduction, which is substantiated by Tran [17], however, Boonkaew saw an apparent promotion of VRE [18] with the silver enhanced formulation they examined. Thus, formulation differences have a big impact on anti-microbial efficacy between the silverenhanced products.…”