## Materials and Methods
### Instrumentation  
Proton nuclear magnetic resonance (1H-NMR) spectroscopy was performed using an AVANCE 500 spectrometer (Bruker, Billerica, MA, USA), standardized to 2.50 ppm with DMSO-\(d_{6}\). Attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectra were measured using an Equinox-55 spectrometer (Bruker, Billerica, MA, USA) equipped with a deuterated triglycine sulfate (DTGS) detector and the corresponding software OPUS. Synthesis of p-(11-Acrylamido)undecanoyloxyphenylhenyl Dimethylsulfonium Methyl Sulfate (AUPDS) Surfiner  
11-Aminoundecanoic acid (19.2 g, 95 mmol) was dissolved in 150 mL of aqueous KOH solution (1.3 mol\(\cdot\)L\({}^{-1}\)) in a 4-necked 1 L flask, equipped with mechanical stirrer, argon (Ar) inlet, thermometer, and dropping funnel. Acryloyl chloride (9.5 g, 105 mmol) was dissolved in 15 mL DCM and slowly added dropwise into the reaction under Ar atmosphere and ice bath. After the addition was completed, the reaction was left stirring at room temperature (RT) for 16 h. The reaction was adjusted to pH 7.0 via dropwise addition of HCl (1 mol\(\cdot\)L\({}^{-1}\)). The colorless and opaque reaction mixture was then filtrated and the solid filtrate was washed five times with HCl solution (0.1 mol\(\cdot\)L\({}^{-1}\)), followed by five washes with water. The resulting white powder was dried under vacuum overnight and was used for the next step without further purification (crude yield: 78%). The second step of the synthesis consists in the Steglich esterification of the obtained 11-acrylamidoundecanoic acid (AAUA). HPDMSMS (4.7 g, 17.6 mmol) was dissolved in 170 mL of acetonitrile and added to a solution of 11-acrylamidoundecanoic acid (5 g, 19.6 mmol) in 370 mL of chloroform under stirring and Ar atmosphere. A solution of DMAP (120 mg, 1.0 mmol) in 5 mL acetonitrile was added dropwise, followed by dropwise addition of a solution of DIC (2.5 g, 19.6 mmol), in 15 mL of acetonitrile, under ice bath. The reaction proceeded under stirring at RT for 72 h. A white precipitate was removed through filtration and the volatile solvents of the filtrate were evaporated, resulting in a white powder. 50 mL of ethyl acetate were added to the powder and the mixture was left stirring at room temperature for 15 min, then the solids were filtered. This process was repeated three times in order to remove the DIC by-product. The white powder was then dried under vacuum (yield: 89%). 1H-NMR and ATR-FTIR spectra are available in the supplementary information (Figures S1 and S2). 1H-NMR (DMSO-\(d_{6}\)): \(\delta\) (ppm) = 8.17-8.10 (m, 2 H), 8.07 (m, 1 H), 7.50 (m, 2 H), 6.25-6.16 (m, 1 H), 6.05 (dd, 1 H), 5.55 (dd, 1 H), 3.38 (s, 3 H), 3.27 (s, 6 H), 3.11 (m, 2 H), 2.62 (m, 2 H), 1.64 (m, 2 H), 1.46-1.20 (m, 14 H). ATR-FTIR: 3308 (s, N-H stretch); 3018 (m, C-H stretch of the phenyl ring); 1587 and 1475 (m, C-H bend of the phenyl ring); 2918 and 2849 (s, C-H stretch of the alkyl chain); 1759 (s, C=O ester); 1653 (s, C=O acryloyl group); 1626 (s, C=C acryloyl group); 1533 (s, N-H). Preparation of PMMA and PS Particles Copolymerized with AUPDS Surfmer Through Mini-Emulsion Polymerization  
For the synthesis of polymeric NPs via mini-emulsion polymerization, a continuous phase (water) was mixed with a dispersed (monomer) phase, which consisted of monomer (either St or MMA), AIBN (initiator), HD (hydrophobic), and AUPDS surfmer, which was used as the only surface active compound. Throughout the formulations, AUPDS surfmer content varied from 0.25 to 8 mol%, AIBN and HD were fixed at 0.5 and 2 mol%, respectively, and cross-linkers (when present) varied from 0.5 to 80 mol%. The term mol% refers only to the compounds on the dispersed phase. Examples of amounts of the dispersed phase for non-cross-linked formulations with AUPDS 2 mol%: 0.94 mg MMA (9.39 mmol), 77 mg AUPDS (0.20 mmol), 8 mg AIBN (0.05 mmol) and 45 mg HD (0.20 mmol); or 0.91 g St (8.74 mmol), 72 mg AUPDS (0.18 mmol), 8 mg AIBN (0.05 mmol), and 41 mg HD (0.18 mmol).