File Name : figure s1.pdf Caption : figure s1. chemical structure of the putrescine-lipid derivative File Name : figure s2.pdf Caption : figure s2. analytical evaluation of the putrescine-lipid derivative by a) 1h-nmr, b) 13c-nmr, and c) hplc-ms/uplc-ms File Name : figure s3.pdf Caption : figure s3. psn-pdna evaluated by scanning transmission electronic microscopy with an inlens detector. File Name : figure s4.pdf Caption : figure s4. stability evaluation of psn and psn-pdna under storage conditions (4ºc) in terms of a) size, b) pdi, and c) zeta potential. File Name : figure s5.pdf Caption : figure s5. physicochemical characterization of psn-pdna upon incubation with supplemented dmem in terms of a) size, b) pdi, c) zeta potential, and d) pdna displacement File Name : figure s6.pdf Caption : figure s6. confocal images of psn-pdna after 4 h of incubation in mda-mb-231 cells. topfluor-labelled psn (green), cy5-pdna (red), nuclei (blue). scale bars, 25 µm. File Name : figure s7.pdf Caption : figure s7. mcherry signal observed under the fluorescence microscope after 24h post-transfection of mda-mb-231 cells. scale bars, 50 µm. File Name : figure s8.pdf Caption : figure s8. cytotoxic effect of psn-pdna-fasl treatment in hcc38 cells was evaluated with different concentrations by cell viability assay. statistical significance was determined by two-tailed unpaired t-test (*p < 0.05; **p < 0.01, ***p < 0.001). data are shown as the mean ± sem. three independent experiments were performed. File Name : figure s9.pdf Caption : figure s9. cytotoxic effect of psn-pdna-fasl treatment in mice. (a) quantification of tumour volume evolution of mda-mb-231 mouse xenografts, treated with the indicated regimens via intratumoral (n=3 per condition). statistical significance was determined by multiple unpaired t-test – comparing both treatments at every time point. (b) biodistribution of topfluor-labelled pdna-control or pdna-fasl treated via intratumoral. quantification of the topfluor fluorescence of the indicated organs ex vivo was performed by normalizing it to the organs’ background from untreated mice. bars represent mean ± sem. *p <0.05; **p<0.01; ***p < 0.001; ****p < 0.0001 File Name : figure s10.pdf Caption : figure s10. pdna-control and pdna-fasl efficiently target breast tumours in vivo. representative images of the ex vivo topfluor fluorescent signal of the different organs of each indicated treatment. it, intratumoral. ip, intraperitoneal.