Research on Silver-Based Wound Dressing: An Ontological Analysis

Silver's ability to kill pathogenic bacteria is being widely researched in environment, consumer, and health-related applications. One topic of voluminous research is the antimicrobial properties of silver and silver in wound dressings. This research literature has been reviewed in articles using qualitative analyses, meta-analyses, systematic reviews, bibliometric analyses, and other grounded methods. We present a new strategy for the analysis of the population of articles on the subject based on an ontology of this topic.

A search of the Scopus database for all peer-reviewed articles on silver in wound dressings yielded a population of 4711 relevant ones. The ontology is a logical deconstruction of the problem: "use of silver species on nanosupports deposited on a matrix with antimicrobial effectiveness assayed by methods to promote wound healing of chronic wounds as determined by recovery". Each bolded term denotes a dimension of the ontology, and each dimension denotes a taxonomy of constituent elements. A Convolutional Neural Network (CNN) was trained using a manually mapped subset of articles. The CNN was then used to map the population of articles.

Out of the 4711 articles, 3079 dealt with silver and wound dressings; the others involved silver, but were not related to wound dressings and were not considered. Overall analysis shows that three classes of silver encompass the entire field: silver nanoparticles (AgNP) (78% of papers), inorganic silver-ion-containing species (7%) and silver associated with organic molecules (15%). AgNP papers have grown exponentially beginning in the early 2000s; there is no clear trend regarding inorganic silver-containing-species papers; whereas with the silver-organics species papers, there has been growth in the past decades, but now the number of publications is stabilizing. Research on the AgNPs has primarily focused on in vitro testing (54%), with very limited animal testing (17%) and human testing (3%). On the other hand, with silver-organics, animal (30%) and human testing (38%) are prominent. Inorganic silver ion species also have been human-tested extensively (43%). Thus, in clinical applications of silver wound dressings, AgNP lags considerably as compared to the other silver species, though academic research in AgNP is robust.

From detailed temporal visualizations of the ontological mapping, the antecedents and consequences of silver in wound dressings are presented. This first ontological analysis is a novel way of visualizing an entire research field and the temporal characteristics of the various dimensions of the ontology provide information on the current state of research as well as where the field is headed.