Novel, silver-ion-releasing nanofibrous scaffolds exhibit excellent antibacterial efficacy without the use of silver nanoparticles

• Published in: Acta biomaterialia 2014-05, Vol.10 (5), p.2096-2104
• Main Authors: Mohiti-Asli, Mahsa, Pourdeyhimi, Behnam, Loboa, Elizabeth G.
• Format: Article
• Language: English
• Subjects: Adult; Anti-Bacterial Agents - pharmacology; Antimicrobial; Biocompatibility; Biocompatible Materials - pharmacology; Cell Proliferation - drug effects; Cell Shape - drug effects; Cell Survival - drug effects; Dermis - cytology; Epidermis - cytology; Escherichia coli - drug effects; Fibroblasts - cytology; Fibroblasts - drug effects; Fibroblasts - ultrastructure; Humans; Ions; Keratinocytes - cytology; Keratinocytes - drug effects; Keratinocytes - ultrastructure; Lactic Acid - chemistry; Mass Spectrometry; Metal Nanoparticles - chemistry; Microbial Sensitivity Tests; Nanofibers; Nanofibers - chemistry; Nanofibers - ultrastructure; Photoelectron Spectroscopy; Polyesters; Polymers - chemistry; Silver; Silver - pharmacology; Staphylococcus aureus - drug effects; Tissue Scaffolds - chemistry; Wound dressing
• ISSN: 1742-7061; 1878-7568
• DOI: 10.1016/j.actbio.2013.12.024

Nanofibers, with their morphological similarities to the extracellular matrix of skin, hold great potential for skin tissue engineering. Over the last decade, silver nanoparticles have been extensively investigated in wound-healing applications for their ability to provide antimicrobial benefits to nanofibrous scaffolds. However, the use of silver nanoparticles has raised concerns as these particles can penetrate into the stratum corneum of skin, or even diffuse into the cellular plasma membrane. We present and evaluate a new silver ion release polymeric coating that we have found can be applied to biocompatible, biodegradable poly(l-lactic acid) nanofibrous scaffolds. Using this compound, custom antimicrobial silver-ion-releasing nanofibers were created. The presence of a uniform, continuous silver coating on the nanofibrous scaffolds was verified by XPS analysis. The antimicrobial efficacy of the antimicrobial scaffolds against Staphylococcus aureus and Escherichia coli bacteria was determined via industry-standard AATCC protocols. Cytotoxicity analyses of the antimicrobial scaffolds toward human epidermal keratinocytes and human dermal fibroblasts were performed via quantitative analyses of cell viability and proliferation. Our results indicated that the custom antimicrobial scaffolds exhibited excellent antimicrobial properties while also maintaining human skin cell viability and proliferation for silver ion concentrations below 62.5μgml−1 within the coating solution. This is the first study to show that silver ions can be effectively delivered with nanofibrous scaffolds without the use of silver nanoparticles.