A cooled fuel injector system of a combustor section of a gas turbine engine is provided. At least a part of the fuel injector system is exposed to core gas flow traveling through the engine. The cooled fuel injector system includes a source of a first cooling fluid and a fuel injector system component. The first cooling fluid is at a temperature lower than a temperature of the core gas flow proximate the fuel injector system. The fuel injector system component includes a vascular engineered structure lattice (VESL) structure, which VESL structure is in fluid communication with the source of the cooling fluid.