Phosphate buffered saline (pbs)

Soya phosphatidylcholine (SPC) was obtained from the Lipoid (Steinhausen, Switzerland), under the brand name of Phospholipon 90. The suppliers of other reagents were: PG (Chempure, Singapore), dialysis tubing (Thermo Scientific, Waltham, MA, USA), ibuprofen and ibuprofen sodium (Sigma, Singapore), tofacitinib citrate (Sigma, Singapore), rhodamine B (Sigma, Singapore), calcein (Sigma, Singapore), lidocaine (Tokyo Kasei, Tokyo, Japan), phosphate buffered saline (PBS) (Vivantis, Singapore). Polyethylene glycol-4-arm, succinimidyl glutarate, bovine fibrinogen, bovine thrombin and calcium chloride were purchased from Sigma-Aldrich, Singapore. Growth medium for culturing keratinocytes, fibroblasts, pericytes and human dermal microvascular cells were purchased from PromoCell, Heidelberg, Germany. ThinCert culture ware and tissue culture flasks were purchased from Greiner Bio-One, Kremsmünster, Austria. Water was purified by using Milli-Q system (Millipore, Billerica, MA, USA).

HepG2 transfected cells on cover slips were fixed with 10% neutral buffered formalin (Sigma-Aldrich, St. Louis, MO, USA) for 10 min before permeabilization with 0.2% Tween 20 (Duchefa, Haarlem, The Netherlands) in PBS (Vivantis, Selangor, Malaysia) for 30 min. This was followed by blocking with 10% Goat serum (Sigma-Aldrich) in PBST (PBS + 0.1% Tween 20) with 100 mM Glycine (Sigma-Aldrich) for 30 min. The cells were then incubated with primary mouse anti-GHR (B-10) monoclonal antibody (1:50; 0.2 mg/ml; sc-137185; Santa Cruz Biotechnology) at room temperature for 1 h. After rinsing 3 times with PBS, the cells were incubated with fluorescein conjugated goat anti-mouse antibody (1:500; 1 mg/ml; 710–1231; Rockland Immunochemicals, Limerick, PA, USA) for another 1 h at room temperature before mounting with mounting medium with DAPI (Vector Laboratories, Burlingame, CA, USA) and examination using the IX73 fluorescence microscope (Olympus, Tokyo, Japan).

ST 688C is a clonal subculture of the S. Thompson strain RM1984 clinically isolated from a salmonellosis patient during the California coriander outbreak in 1999, kindly provided by Dr. Maria Brandl (U.S. Department of Agriculture, Agricultural Research Service, Albany, CA, United States). ST 889B was previously isolated from basil (Delbeke et al., 2015 (link)), kindly provided by Prof. Mieke Uyttendaele (Ghent University). The frozen cultures of bacteria were activated by transferring twice consecutively (37°C, 24 h) in sterile tryptic soy broth (TSB, Oxoid, Basingstoke, Hampshire, England). The stock cultures of bacteria were maintained on tryptic soy broth (TSA, Oxoid) plates stored at 4°C. A single colony from TSA was transferred into 10-ml TSB and incubated at 37°C for 24 h. A 1-ml portion of the bacterial suspension was centrifuged at 9,000 × g at 4°C, washed twice in phosphate-buffered saline (PBS; Vivantis, Inc., Oceanside, CA, United States), serially diluted in 0.1% peptone water (PW; Oxoid) to appropriate concentration to obtain the working cultures of bacteria for downstream experiments.

The 0.05% w/v 2-hydroxy-4-(2-hydroxy-ethoxy)-2-methyl-propiophenone (HHEMP) photoinitiator solution (33 wt% Irgacure 2959; Ciba, Timonium, MD, USA) was prepared by dissolving HHEMP in phosphate buffered saline (PBS) diluted to 1× concentration (Vivantis, Selangor, Malaysia) at 70 °C. The HHEMP photoinitiator solution was sterilized by filtration with a 0.2 µm membrane syringe filter (Pall Corporation, Port Washington, NY, USA). As indicated by the company, a pore size of 0.2 µm was suitable for producing sterile filtrate. In addition, the prepolymer solution is further sterilized when being subjected to UV irradiation. MeHA prepolymer solution was then prepared by dissolving lyophilized MeHA at a concentration of 5% w/v in 0.05% w/v HHEMP photoinitiator solution.