Isopropanol

The fifth passage of UMSC (or OMSC) were transferred into 6-well plates at the density of 3×10⁵/well. After 80% density, the culture medium was removed, with a culture medium for the induction of lipoblasts by a previous study (Lei et al., 2013 (link)). After induction with medium A for 3 days, fat induction medium B was used for 1 day. After circulation for 21 days, the medium was sucked out, and the cells were washed gently with PBS once and fixed with 4% paraformaldehyde for 15 min. After staining the cells using 0.5% Oil Red O (Sigma-Aldrich, St. Louis, MO, United States) for 10 min, they were washed carefully with isopropanol (Guangzhou chemical reagent factory, Guangzhou, China), gently rinsed with PBS three times, and then observed and photographed under a microscope.

Thermoplastic polyurethane (TPU, WHT-1570IC) with a density of 1.15 g/cm³ was purchased from Wanhua Chemical Group Co., Ltd. (Yantai, China). The hexagonal boron nitride (h-BN, purity > 99.5%) was obtained from Qingzhou Materials Co., Ltd. (Qingzhou, China). Cobalt (II) acetate tetrahydrate (C₄H₆CoO₄·4H₂O, 99.5%) was obtained from Shanghai Macklin Biochemical Co. Ltd., Shanghai, China. HCCP (purity, 98%) were supplied by J&K Chemical Co., Ltd. (Shanghai, China). Isopropanol (purity > 99.7%) and ammonia (NH₃·H₂O, 25 wt%) were supplied by Guangzhou Chemical Reagent Factory.

Melamine (99%, Aladdin), phosphoric acid (≥85%, Guangzhou Chemical Reagent Factory), isopropanol (Guangzhou Chemical Reagent Factory), ethanol (Runjie Chemistry), glycerol (Runjie Chemistry), AAO substrate with a diameter of 15 mm (with a pore size of 160–200 nm, PuYuan Nanotechnology Limited Company). All of the materials were used as purchased without further purification.