Prototype Development of the Intelligent Hydrogel Wound Dressing and Its Efficacy in the Detection of Model Pathogenic Wound Biofilms

Abstract

The early detection of wound infection in situ can dramatically improve patient care pathways and clinical outcomes. There is increasing evidence that within an infected wound the main bacterial mode of living is a biofilm: a confluent community of adherent bacteria encased in an extracellular polymeric matrix. Here we have reported the development of a prototype wound dressing, which switches on a fluorescent color when in contact with pathogenic wound biofilms. The dressing is made of a hydrated agarose film in which the fluorescent dye containing vesicles were mixed with agarose and dispersed within the hydrogel matrix. The static and dynamic models of wound biofilms, from clinical strains of Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Enterococcus faecalis, were established on nanoporous polycarbonate membrane for 24, 48, and 72 h, and the dressing response to the biofilms on the prototype dressing evaluated. The dressing indicated a clear fluorescent/color response within 4 h, only observed when in contact with biofilms produced by a pathogenic strain. The sensitivity of the dressing to biofilms was dependent on the species and strain types of the bacterial pathogens involved, but a relatively higher response was observed in strains considered good biofilm formers. There was a clear difference in the levels of dressing response, when dressings were tested on bacteria grown in biofilm or in planktonic cultures, suggesting that the level of expression of virulence factors is different depending of the growth mode. Colorimetric detection on wound biofilms of prevalent pathogens (S. aureus, P. aeruginosa, and E. faecalis) is also demonstrated using an ex vivo porcine skin model of burn wound infection.

Antimicrobial Properties of Diamond-Like Carbon/Silver Nanocomposite Thin Films Deposited on Textiles: Towards Smart Bandages

“…Therefore, it is very important to have the antibacterial surface directly on the bandage to avoid the formation of these bacteria films, preventing bacteria multiplication inside the bandage [5]. Bacterial infections are usually treated with antibiotics; however, a good effect is not obtained in every case, and this is because many bacteria are immunized to antibiotics after being subjected to the treatment [6].…”

Use of Nanoparticles As Contrast Agents for the Functional and Molecular Imaging of Abdominal Aortic Aneurysm

“…Iron oxide NPs have been reported to have a high affinity for macrophages (48–50). Hence, these NPs, specifically the subset with diameters <50 nm known as ultrasmall superparamagnetic iron oxide nanoparticles (USPIOs), have been used as agents to aid imaging of AAAs in both animal models and patients (30–35). USPIOs such as ferumoxytol are composed of an iron oxide core enclosed by a hydrophilic coating that readily accrues in neutrophils and macrophages (51).…”

“…Both animal and human studies have suggested that NPs, particularly those with an iron oxide component, can be taken up by AAAs and identified on imaging (30–35). We highlight some of these studies in the following sections.…”

“…NPs have been employed in imaging AAA (33, 34) and to enhance magnetic resonance imaging (MRI) detection of endoleaks following endovascular aneurysm repair (29). NP-based biofilms have been utilized to detect infection (35). …”

Self-Healing Hydrogels as Biomedical Scaffolds for Cell, Gene and Drug Delivery

“…In other words, the self-healing endows the material more than one life. There is much potential relevance of selfhealing hydrogels in the fields of biosensors, wound dressing, shape memory material and biomedical carrier [9][10][11][12][13][14][15][16][17] .…”