The present clinical trial is designed to assess the effectiveness of BioChaperone PDGF-BB applied at 4 µg/cm² every other day for up to 20 weeks and associated to Standard of Care as compared to Standard of Care alone for the treatment of neuropathic and neurovascular diabetic foot ulcers.(In order to ensure the double-blinding of the treatments, a sterile normal saline solution presented in the same multi-dose spray vials than BioChaperone PDGF-BB will be applied on patients of the control group).