Project description:Iron is an essential nutrient for the opportunistic pathogen Pseudomonas aeruginosa, as for almost all living organisms. To access this element, the pathogen is able to express at least 15 different iron-uptake pathways, the vast majority involving small iron chelators called siderophores. Indeed, P. aeruginosa produces two siderophores, pyoverdine and pyochelin, but can also use many produced by other microorganisms. This implies that the bacterium expresses appropriate TonB-dependent transporters (TBDTs) at the outer membrane to import the ferric form of each of the siderophores used. These transporters are highly selective for a given ferri-siderophore complex or for siderophores with similar chemical structures. Here, we show that P. aeruginosa can also use rhizoferrin, staphyloferrin A, aerobactin, and schizokinen as siderophores to access iron. Growth assays in iron-restricted conditions and 55Fe uptake assays showed that the two alpha-carboxylate type siderophores rhizoferrin-Fe and staphyloferrin A-Fe are transported into P. aeruginosa cells by the TBDT ActA (PA3268). Among the mixed alpha-carboxylate/hydroxamate type siderophores, we found aerobactin-Fe to be transported by ChtA (as previously described) and schizokinen-Fe by ChtA and another unidentified TBDT.
Project description:This Phase I clinical trial aims to evaluate the safety, tolerability, pharmacokinetics (PK) profile and preliminary efficacy of intratumoral injection of Carbon Nanoparticle-Loaded Iron [CNSI-Fe(II)] in patients with advanced solid tumors. The study also aims to observe dose-limiting toxicities (DLT) of CNSI-Fe(II) to determine the maximum tolerated dose (MTD) or the highest injectable dose in humans, providing dosing guidelines for future clinical studies. CNSI-Fe(II) shows promise as an innovative tumor therapeutic agent due to its unique properties of ferroptosis. The study primarily focuses on assessing the potential efficacy of CNSI-Fe(II) in patients with advanced solid tumors, particularly in patients with Kras mutation, e.g., pancreatic cancer patients.