Genipin-Crosslinked Gelatin Hydrogel for the Detection and Treatment of Active Metalloprotease Releasing Pseudomonas aeruginosa.

We report a genipin-crosslinked gelatin hydrogel for the detection of the pathogenic strains of Pseudomonas aeruginosa releasing active metalloproteases. Enzymatic degradation of the blue gel gives a clear visual signal that indicates the presence of P. aeruginosa. A total of 36 strains of both Gram-positive and Gram-negative bacteria were tested and only P. aeruginosa strains caused degradation of the gels within 24 h. Gene sequencing revealed that P. aeruginosa strains with mutations in their quorum sensing operon were not able to degrade the hydrogels even though the genes coding for metalloproteases were present. Finally, we created a gel multilayer that can both detect and treat active strains of P. aeruginosa through the release of bacteriophage. Our system provides a simple and reproducible assay for P. aeruginosa metalloproteases and showcases the feasibility of responsive wound dressings able to both detect and treat P. aeruginosa infection.