The potential of photo-deposited silver coatings on Foley catheters to prevent urinary tract infections

Catheter-associated urinary tract infection (CAUTI) represents one of the most common causes of morbidity and mortality. The resistance demonstrated by many microorganisms to conventional antibiotic therapies and the increasing health-care costs have recently encouraged the definition of alternative preventive strategies,which can have a positive effect in the management of infections. Antimicrobial urinary catheters have been developed through the photo-chemical deposition of silver coatings on the external and luminal surfaces. The substrates are exposed to ultraviolet radiation after impregnation into a silver-based solution, thus inducing the in situ synthesis of silver particles. The effect of the surface treatment on the material was investigated through scanning electron microscopy (SEM) and silver ion release measurements. The ability of microorganisms commonly associated with urinary tract infections was investigated in terms of bacterial viability, proliferation and biofilm development, using Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis as target organisms. The silver coatings demonstrated good distribution of silver particles to the substrate, and proved an effective antibacterial capability in simulated biological conditions. The low values of silver ion release demonstrated the optimum adhesion of the coating. The results indicated a good potential of silver-based antimicrobialmaterials for prevention of catheter-associated urinary tract infection

Aminated nanomicelles as a designer vaccine adjuvant to trigger inflammasomes and multiple arms of the innate immune response in lymph nodes

Chanyoung Song,1,* Hathaichanok Phuengkham,1,* Sun-Young Kim,1 Min Sang Lee,2 Ji Hoon Jeong,2 Sung Jae Shin,3 Yong Taik Lim1 1SKKU Advanced Institute of Nanotechnology, School of Chemical Engineering, 2Department of Pharmacy, Sungkyunkwan University, Suwon, 3Department of Microbiology and Institute for Immunology and Immunological Diseases, Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul, Republic of Korea *These authors contributed equally to this work Abstract: In this study, we suggest a designer vaccine adjuvant that can mimic the drainage of pathogens into lymph nodes and activate innate immune response in lymph nodes. By the amination of multivalent carboxyl groups in poly-(γ-glutamic acid) (γ-PGA) nanomicelles, the size was reduced for rapid entry into lymphatic vessels, and the immunologically inert nanomicelles were turned into potential activators of inflammasomes. Aminated γ-PGA nanomicelles (aPNMs) induced NLRP3 inflammasome activation and the subsequent release of proinflammatory IL-1β. The NLRP3-dependent inflammasome induction mechanism was confirmed through enzyme (cathepsin B and caspase-1) inhibitors and NLRP3 knockout mice model. After the aPNMs were combined with a clinically evaluated TLR3 agonist, polyinosinic–polycytidylic acid sodium salt (aPNM-IC), they triggered multiple arms of the innate immune response, including the secretion of pro-inflammatory cytokines by both inflammasomes and an inflammasome-independent pathway and the included type I interferons. Keywords: vaccine adjuvant, nanoparticles, innate immunity, antigen-presenting cells, lymphatic vessel, type I interfero