Perspectives on antibacterial performance of silver nanoparticle-loaded three-dimensional polymeric constructs

Silver nanoparticle (AgNP)-loaded polymeric constructs are widely investigated for potential applications as drug delivery systems, wound dressings, and antibiofouling biomaterials. Herein, the authors present several methods for fabricating such materials and evaluate their efficacy against Escherichia coli. H₂O_(v) plasma surface modification is employed to enhance material surface wettability (explored by water contact angle goniometry) and nanoparticle incorporation. Compositional analyses reveal that incorporation of AgNPs on the surface and bulk of the materials strongly depends on the fabrication methodology. More importantly, the nature of AgNP incorporation into the polymer has direct implications on the biocidal performance resulting from the release of Ag⁺. The materials fabricated herein fell significantly short of healthcare standards with respect to antimicrobial behavior, and, in comparing their results to numerous literature studies, the authors identified a glaring disparity in the way such results are often described. Thus, this work also contains a critical evaluation of the literature, highlighting select poor-performing materials to demonstrate several shortcomings in the quantitative analysis and reporting of the antibacterial efficacy of AgNP-loaded materials. Ultimately, recommendations for best practices for better evaluation of these constructs toward improved antibacterial efficacy in medical settings are provided.