Compositions of nanoparticles for treatment of neuropathic pain

A method of treating peripheral neuropathic pain in a subject comprising administering nanoparticles or aggregates thereof to a subject having peripheral neuropathic pain and wherein the nanoparticles or nanoparticle aggregates are not exposed to an electric field nor to any other external activation source, wherein i) the nanoparticle material is a metallic conductor selected from Ir, Pd, Pt, Au and any mixture thereof;

• an organic material having contiguous sp2 hybridized carbon centers in its structure selected from poly(3,4-ethylenedioxythiophene) (PEDOT), poly(styrene sulfonate) (PSS) and a mixture thereof;
• or an insulator material with a dielectric constant εijk equal to or below 100 which is a metal oxide or a mixed metal oxide wherein the metal is Zr and/or Re, ii) when the nanoparticle material is a metallic conductor, the nanoparticle or nanoparticle aggregate has a median population core size of at least 45 nm, and iii) the core of the nanoparticle or nanoparticles' aggregate is coated with a biocompatible coating providing a neutral or a negative surface charge when measured in a solution of water having an electrolyte concentration between 0.001 and 0.2 M, a concentration of the nanoparticles or nanoparticle aggregates material between 0.01 and 10 g/L and a pH between 6 and 8.