silicon and Pseudomonas-Infections

There is an urgent need for new materials to treat bacterial infections. In order to improve antibacterial delivery, an anti-infective nanomaterial is developed that utilizes two strategies for localization: i) a biodegradable nanoparticle carrier to localize therapeutics within the tissue, and ii) a novel tandem peptide cargo to localize payload to bacterial membranes. First, a library of antibacterial peptides is screened that combines a membrane-localizing peptide with a toxic peptide cargo and discovers a tandem peptide that displays synergy between the two domains and is able to kill Pseudomonas aeruginosa at sub-micromolar concentrations. To apply this material to the lung, the tandem peptide is loaded into porous silicon nanoparticles (pSiNPs). Charged peptide payloads are loaded into the pores of the pSiNP at ≈30% mass loading and ≈90% loading efficiency using phosphonate surface chemistry. When delivered to the lungs of mice, this anti-infective nanomaterial exhibits improved safety profiles over free peptides. Moreover, treatment of a lung infection of P. aeruginosa results in a large reduction in bacterial numbers and markedly improves survival compared to untreated mice. Collectively, this study presents the selection of a bifunctional peptide-based anti-infective agent and its delivery via biodegradable nanoparticles for application to an animal model of lung infection.

Topics: Animals; Anti-Bacterial Agents; Lung Diseases; Mice; Nanoparticles; Peptides; Porosity; Pseudomonas aeruginosa; Pseudomonas Infections; Silicon

Zinc eluted from siliconized latex (SL) increases resistance of Pseudomonas aeruginosa to imipenem in vitro. A foreign body peritonitis model was used to evaluate the activity of imipenem using SL or silicone (S) implants. No differences were observed in mortality, positive blood cultures and tissue bacterial counts between SL and S implants. Implant-associated counts, however, were significantly higher in the SL group. It is concluded that SL decreases the activity of imipenem against P. aeruginosa.

Topics: Animals; Anti-Bacterial Agents; Bacterial Load; Catheters; Disease Models, Animal; Drug Antagonism; Female; Foreign Bodies; Imipenem; Latex; Liver; Mice; Mice, Inbred C57BL; Peritonitis; Pseudomonas aeruginosa; Pseudomonas Infections; Silicon; Spleen; Treatment Outcome; Zinc