*2.3. In Vitro Drug Release*

DOX release profile was studied in triplicate using dialysis (14 kDa cut-off cellulose membranes; Sigma; Germany) in phosphate-buffered saline media (PBS, pH 7.4). A total of 0.3 mL of DOX-loaded SLPs (SLPs-DOX) dispersion at a concentration of 20 mg/mL of DOX were added into the membrane bags that were submerged in PBS and stirred at 300 rpm at ca. 37 ◦C. The dialysis membrane allowed drug diffusion into the PBS while retaining the SLPs. Samples of 1 mL were taken at different times and measured using fluorescence spectroscopy in an Edinburgh Inst. FLSP920 spectrofluorometer (Livingston, UK). Values were compared to those of the calibration curve prepared for DOX (Figure S3). Finally, DOX release data in PBS pH 7.4 were fitted to a Korsmeyer–Peppas kinetic model.
