Sodium azide

The detector was calibrated and characterized using an aqueous solution containing fluorescent beads with a nominal diameter of 200 nm (F-8809, Thermo Fisher Scientific, Waltham, MA, USA) at a concentration of 4 * 10⁶ particles per milliliter. In addition, the solution contained Rhodamine to detect the flow direction even in case of clogging (10 µg/mL; Quality for Fluorescence, Merck, Darmstadt, Germany), sodium chloride (5.48 mg/mL, >99.8%, Carl Roth, Karlsruhe, Germany), sodium azide (20 µg/mL, >99%, Carl Roth, Karlsruhe, Germany), and sodium dodecyl sulfate (0.1 mg/mL, >99%, Merck, Darmstadt, Germany).
For the precipitation experiments, castor oil (5 mg/mL, Henry Lamotte Oils, Bremen, Germany), polysorbate 80 (2.5 mg/mL, BioXtra, Merck, Darmstadt, Germany), and Nile Red (8 µg/mL, technical grade, Merck, Darmstadt, Germany) were dissolved in ethanol and filtered through a 200 nm syringe filter (Polypropylene, VWR International, Radnor, PA, USA). The aqueous solution used consisted of deionized water filtered through a 200 nm syringe filter.
The system was purged with a 2% solution of Hellmanex (Hellmanex III, Helma Analytics, Müllheim, Germany) in deionized water, which was filtered through a 200 nm syringe filter (Polypropylene, VWR International, Radnor, PA, USA).
The gas bubble generation and pressurizing of vials was done with nitrogen.

The KSHV latent nuclear antigen (LANA) was detected by immunfluorescence staining. SLK cells (2.5×10⁴ cells per well) were seeded in 8-well μ-slides (Ibidi) one day prior to infection. Cells were infected with 50 μL virus stock for 6 h and washed with PBS. Infected cells were cultured until 24 h post-infection and fixed with 4% (w/v) paraformaldehyde for 15 min at RT. Fixed cells were washed with PBS, incubated in 50 mM (w/v) NH₄Cl for 20 min at RT, washed again with PBS, permeabilized with PBS/2% (v/v) Triton X-100 (Roth) for 20 min at RT, and blocked in TBS with 5% (w/v) glycine (Serva), 5% (w/v) BSA (Sigma-Aldrich), 0.05% (v/v) Tween (Roth), 0.05% (w/v) sodium azide (Roth) for 30 min at RT. Cells were stained using a polyclonal rabbit anti-LANA antiserum³³ for 1 h at RT, followed by three washes with PBS and incubation with a goat anti-rabbit-AlexaFluor555 (Thermo Fisher) secondary antibody and 4′,6-diamidine-2′-phenylindole dihydrochloride (DAPI, Sigma-Aldrich) for 30 min at RT. Fluorescence images were acquired by using a Nikon A1+ confocal laser scanning microscope.

All feed solutions were preserved from microbiological spoilage by addition of 0.02% (w/w) sodium azide (Carl Roth, Karlsruhe, Germany) in order to avoid the formation of biofilms that could affect the results. For preliminary experiments a model solution was used that was prepared by dissolving a pharmaceutical-grade α-lactose monohydrate (Carl Roth, Karlsruhe, Germany) in deionized water in the amounts needed to reach the desired lactose concentrations of approximately 25, 50 and 75 g/L.
Fresh sweet whey permeate was taken from a feed line of an industrial filtration process of a local dairy plant where it had been separated by a 10 kDa UF membrane and was stored at 4 °C until use. The average composition of the sweet whey permeate used is shown in Table 1.

Cells from days 4, 6, and 8 were transferred into a 96-well round-bottom plate and washed twice with FACS buffer [PBS + 0.02% sodium azide (Roth, Germany) + 2 mM EDTA (Sigma-Aldrich) + 2% h.i. FBS]. Extracellular staining was performed with CD4 APC-Cy7 (RPA-T4; BD Biosciences), CD8 BV605 (RPA-T8; BioLegend), the dead cell marker Zombie Aqua (BioLegend), CD25 PE-Cy7 (BC96; BioLegend), CD69 PE (FN50; BD Biosciences) and incubated for 20 min at 4°C. All antibodies were used at pretested optimal concentrations. Cells were washed twice with FACS buffer. Approximately 500,000 cells were acquired on the same day using an LSRFortessaTM SORP (BD Biosciences, USA) equipped with the DIVA Software (Version 6, BD Biosciences, USA). The percentage of proliferating CD4⁺ cells was determined by assessment of CFSE-negative cells and activation by the percentage of CD69⁺ or CD25⁺.

The triglyceride trimyristin (Dynasan^® 114) was donated by IOI Oleo, Witten, Germany, and the surfactant poloxamer 407 (Kolliphor^® P127) by BASF AG, Ludwigshafen, Germany. Sodium alginate (Manugel^® GMB) was a kind gift from FMC International, Wallingstown, Ireland. As estimated by the supplier, the molecular weight was ~124 kDa, the content of guluronic acid was 60–70%, and that of mannuronic acid was 30–40%. Cholesteryl nonanoate was purchased from TCI, Zwijndrecht, Belgium. tetrahydrofuran (HPLC grade), acetonitrile (HPLC grade), bovine serum albumin (BSA, heat shock fraction, pH 7, ≥98%), and the drugs fenofibrate and retinyl acetate were obtained from Sigma-Aldrich, Steinheim, Germany. Orlistat was donated by Formosa Laboratories Inc., Taoyuan, Taiwan. Sodium azide, anhydrous glycerol, calcium chloride, acetonitrile (LC MS grade), and tetrahydrofuran (ultra LC MS grade) were obtained from Carl Roth, Karlsruhe, Germany. All materials were used as received. Water was purified by deionization and filtration (EASYpureTM LF, Barnstead, Dubuque, IA, USA) or was of bidistilled quality. The logP values of the drugs were obtained from DrugBank (calculated by ALOGPS).

Cells were collected and washed once in buffer (PBS, 1% FBS (Biochrom), 0.5% Sodium azide (Carl-Roth)). The supernatant was discarded completely and 50 µL staining solution in buffer containing all labeling antibodies was added and incubated for 30 min at 4 °C. Subsequently, the suspension was washed once with buffer and suspended in buffer containing 1% Paraformaldehyde (PFA, Carl-Roth) and analyzed the next day. The following antibodies were used for macrophage staining: CD163-Fitc (1:20, BioLegend, San Diego, CA, USA), CD80-PE (1:20, BioLegend), CD16-PerCPCy5.5 (1:200, BioLegend), CD206-APC (1:100, BioLegend), CD14-APCCy7 (1:100, BD, Franklin Lakes, NJ, USA), HLA-DR-PeCy7 (1:400, BioLegend), Life/Dead-V510 (1:100, Thermo-Fisher). Following antibodies were used for T cell staining in the proliferation setup: CD8-PE (1:50, Miltenyi Biotec), CD4-APC (1:100, BioLegend), CD3-APCCy7 (1:100, BioLegend).