Development and Characterization of Highly Stable Silver NanoParticles as Novel Potential Antimicrobial Agents for Wound Healing Hydrogels.

Alessio Massironi,Rui L Reis,Pedro Sousa Babo,Dario Puppi,Federica Chiellini,Manuela Estima Gomes,Albina Ribeiro Franco

doi:10.3390/ijms23042161

Alessio Massironi, Rui L Reis + Show 5 more

Open Access

https://doi.org/10.3390/ijms23042161

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Abstract

Recurrent microbial infections are a major cause of surgical failure and morbidity. Wound healing strategies based on hydrogels have been proposed to provide at once a barrier against pathogen microbial colonization, as well as a favorable environment for tissue repair. Nevertheless, most biocompatible hydrogel materials are more bacteriostatic than antimicrobial materials, and lack specific action against pathogens. Silver-loaded polymeric nanocomposites have efficient and selective activity against pathogenic organisms exploitable for wound healing. However, the loading of metallic nanostructures into hydrogels represents a major challenge due to the low stability of metal colloids in aqueous environments. In this context, the aim of the present study was the development of highly stable silver nanoparticles (AgNPs) as novel potential antimicrobial agents for hyaluronic acids hydrogels. Two candidate stabilizing agents obtained from natural and renewable sources, namely cellulose nanocrystals and ulvan polysaccharide, were exploited to ensure high stability of the silver colloid. Both stabilizing agents possess inherent bioactivity and biocompatibility, as well as the ability to stabilize metal nanostructures thanks to their supramolecular structures. Silver nitrate reduction through sodium borohydride in presence of the selected stabilizing agents was adopted as a model strategy to achieve AgNPs with narrow size distribution. Optimized AgNPs stabilized with the two investigated polysaccharides demonstrated high stability in phosphate buffer saline solution and strong antimicrobial activity. Loading of the developed AgNPs into photocrosslinked methacrylated hyaluronic acid hydrogels was also investigated for the first time as an effective strategy to develop novel antimicrobial wound dressing materials.

Highlights

Post-surgical wound infections are a major burden worldwide
The aim of the present study was the development of highly stable AgNPs obtained through chemical reduction in the presence of either cellulose nanocrystals (CNCs) or ulvan polysaccharide as novel antimicrobial agents for hydrogels preparations
Comparison ofthus the was optimized in order of to the adopt the same synthesis approach forThe all formulations surface plasmon resonance band (SPR)

Summary

Introduction

Post-surgical wound infections are a major burden worldwide. Hydrogels have been investigated as suitable materials to prevent post-surgical bacterial infections, in the form of wound dressing patches or coatings of medical devices, acting as a barrier against pathogen microbial colonization, and providing a favorable environment for wound healing [1].hydrogels with antimicrobial properties are currently included in different medical tools such as bandages, hard implants for bone and teeth reconstruction, personal care products, sanitizers, and disinfectants to be applied to open wounds [2]. Post-surgical wound infections are a major burden worldwide. Hydrogels have been investigated as suitable materials to prevent post-surgical bacterial infections, in the form of wound dressing patches or coatings of medical devices, acting as a barrier against pathogen microbial colonization, and providing a favorable environment for wound healing [1]. Hydrogel-based devices can provide to the wounds a moist environment while absorbing extensive exudate effectively [3]. Polymeric hydrogels can present a macromolecular structure similar to native extracellular matrix (ECM) promoting the healing processes, and can be loaded with antimicrobial agents and growth factors [3]. The antimicrobial activity can be provided through the loading of biocidal agents as well as by the inherent biocidal properties of the polymer matrix [4]. Antimicrobial hydrogels are commonly divided into four main categories: hydrogels with inherent antimicrobial properties [5], antibiotic-loaded hydrogels [6], biological extract-loaded hydrogels [7,8] and metal nanoparticles-loaded hydrogels [9,10], the latter displaying the strongest bioactivity [11]

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