Infected diabetic foot ulcers (DFUs) are a frequent complication of diabetes, with limb amputation being highly prevalent worldwide. Staphylococcus aureus and Pseudomonas aeruginosa are the main microbial inhabitants of infected DFUs, often gaining antimicrobial-resistance[1]. Nanoparticle (NP)-mediated therapies may overcome this problem, as they are able to carry, protect and release the load(s) in a controlled manner[2, 3]. As payloads, Essential oils (EOs) exert quick and strong bactericidal action. Eugenol, in particular, is an amphipathic hydroxyphenyl propene, highly bactericidal towards these pathogens[1]. This work proposes EO-encapsulation into polyelectrolyte complexed (PEC) NPs fabricated with quaternized cellulose (QC) and carboxymethyl lignin (CML)[4]. The presence of a peak at 1482 cm^-1 in Fourier-transform infrared spectroscopy (FTIR) spectra showcased vibrations of methyl groups of cationic quaternary amines grafted into the cellulose chain, while two absorption bands at 1645 cm^-1 and 1417 cm^-1 emphasized the introduction of negatively charged carboxyl groups into lignin’s skeletal bonds. Minimum inhibitory concentrations (MIC) of cinnamon leaf oil (CLO) and clove oil (CO) EOs were previously established against reference strains of S. aureus and P. aeruginosa. The MIC values were 0.82 mg/mL and 0.83 mg/mL for CLO and 39.3 mg/mL and 52.8 mg/mL for CO, respectively[1]. At optimized conditions, EOs were added at MIC to the anionic polyion (CML) before complexation, then added to the polycation (QC) and ultrasonicated to form EO-loaded QC/CML PEC NPs. The loading efficiency of dialysis-purified NP dispersions was monitored by UV-Vis, being 83% for QC/CML/CLO NPs and 12% for QC/CML/CO NPs. Bright-field and fluorescence microscopy (using Nile Red) confirmed the formation of EO-PEC NPs. Antimicrobial activity of loaded PEC NPs was confirmed through agar diffusion and time-kill kinetics assays[1]. Preliminary data pointed to the potential of EO-loaded PECs to work as a therapeutic alternative to fight some of the pathogens colonizing DFUs.