Dimethylacetamide

Dimethylformamide, dimethylacetamide, acetonitrile, toluene, methanol, chloroform, acetone, and deuterated chloroform were purchased from MERCK and were used as received. Tetrafluoroterephthalonitrile (TFTPN, 98%, MERCK) was heated to around 150 °C and the pure product collected without vacuum. 5,5′,6,6′-Tetrahydroxy-3,3,3′,3′-tetramethyl-1,1′-spirobisindane (TTSBI, 98%, Alfa Aesar) was dissolved in methanol and re-precipitated from dichloromethane before use. Anhydrous potassium carbonate (K₂CO₃, 99.0%, MERCK) was dried in an oven at 110 °C overnight before use. Amoxicillin, doxycycline, ciprofloxacin, and penicillin G were purchased from Alfa Aesar. Double distilled water (Mill-Q with a conductivity of 18.2 MΩ.cm) was used to make stock solutions and the desired concentrations of the studied antibiotics.

Compounds 4-methoxyphenylboronic acid, 4-nitrophenyl boronic acid, Pd/C,[1,1'-biphenyl]-2-yldicyclo hexyl phosphine and K₂CO₃ were purchased from Sigma-Aldrich Chemical Co., and were used without further purification. CPZ, TDM and VOR were commercially available and used as received. Dimethylacetamide was purchased from Merck KGaA.

The graphene nanoplatelets (xGnP-M5, 5 μm particle size, surface area 120–150 m² g⁻¹), sodium metal (ingot, 99.95%), naphthalene (99%), dimethylacetamide (DMAc, anhydrous, 99.8%), 4-bromothioanisole (97%), chloroplatinic acid hydrate (≥99.9%, H₂PtCl₆.xH₂O, assuming x = 2), sodium borohydride (≥98.0%), and urea (≥99.5%, powder, Merck) were supplied by Sigma Aldrich (Gillingham, UK). The acetone (99.8%) and propan-2-ol (99%) were supplied by VWR Ltd. (Luttleworth, UK). The Nafion^® Dispersion (Type DE-1021, Lot SGWO8-02SC) was obtained from DuPont Fluoroproducts (Richmond, VA, USA). The carbon black (Vulcan XC72R) and Freudenberg H23C7 was supplied by Fuel Cell Stores (College Station, TX, USA). The argon (99.95%) was supplied by BOC gases (Munich, Germany).
The water was deionised using an Elga PureLab Chorus on site. The DMAc was dried over 4 Å molecular sieves (ca. 15 vol.%, activated at 200 °C, 10 mbar, 12 h) for 48 h before use. The graphene nanoplatelets were dried under vacuum (200 °C, 10⁻⁷ mbar, 16 h) before use. All the other chemicals were used as supplied.

Tert-butanol (t-BuOH), dimethyl sulfoxide (DMSO), diethyl ether, ethyl acetate, acetone, methanol (MeOH), dimethylacetamide (DMA), 2,2′-azobis(isobutyronitrile) (AIBN), 2,2′-azobis(4-methoxy-2,4-dimethylvaleronitrile) (V70), acetic acid (CH₃COOH), dexamethasone (DEX), 4-(2-oxopropyl)benzoic acid (OPB), N-(3 dimethylaminopropyl)-N′-ethylcarboiimide hydrochloride (EDC), 4-(dimethylamino)pyridine (DMAP), dimethylformamide (DMF), dichloromethane (DCM), and porcine liver esterase were obtained from Merck KGaA (Darmstadt, Germany). The fluorescent dyes cyanine 5.5-succinimidyl ester (Cy5.5-NHS ester) and cyanine 5.5 (Cy 5.5) were obtained from Lumiprobe GmbH, (Hannover, Germany). Milli-Q water (H₂O) was used for all experiments and obtained from the appliance Millipore Merck, Darmstadt, Germany.(resistivity 18.2 MΩ·cm, 25 °C, organic carbon ≤ 5 ppb). dexamethasone (2 mg/mL of excipient QSP) used in in vivo experiments was purchased from Vibrac S.A. (Carros, France) and 3-aminophthalhydrazide monosodium salt was obtained from Thermo Fisher GmbH (München, Germany). Complete Freund’s adjuvant (CFA) was obtained from Becton, Dickinson and Company, Franklin Lakes, NJ, USA.

All animal experiments were performed according to and approved by the Institutional Animal Care and Use Committee of the Medical College of National Taiwan University (NTU; No. 20201046; IACUC) under standard conditions at 23°C and 12/12 h light/dark (7AM–7PM.) cycle in animal centers of NTU Medical College, which is accredited by the Association for Assessment and Accreditation of Laboratory Animal Care International.
Male C57BL/6J mice are fed on a HFHSD (58% calorie from fat and 12.5% calorie from sucrose, cat no. D12331i, Research Diets) from the age of 8 wk. GSK3α-specific small-molecule inhibitors BRD0705 were dissolved with 3% dimethylacetamide (Sigma-Aldrich) and 10% cremophor (Sigma-Aldrich) in water and were delivered by oral gavage once daily at the dose of 30 mg/kg from the age of 10 wk. Body weight was recorded weekly. At the end of the experiments, mice fasted overnight were i.p. injected with and without human insulin (Humulin-R, Eli Lilly) at the dose of 2 IU/kg. The snap-frozen soleus muscles were harvested 30 min after insulin injection and were homogenized and lysed in radioimmunoprecipitation assay buffer supplied with cOmplete Protease Inhibitor Cocktail (Sigma-Aldrich) and PhosSTOP phosphatase Inhibitor Cocktail (Sigma-Aldrich) for the immunoblotting of total and phospho-Dyn2 and other insulin-signaling components.

Polybenzimidazole (PBI), as a class of heat and chemicals extremely resistant polymers, was selected for the preparation of electrospun catalytic membranes. PBI was purchased from PBI Performance Products, Inc., Charlotte, NC, USA in the form of a solution (26 wt.%) in dimethylacetamide involving a stabilizer based on LiCl salt. Prior to the electrospinning process, the parent solution of PBI was diluted by a dimethylacetamide (≥99%, purchased from Sigma-Aldrich, St. Louis, MO, USA) solvent to 15 wt.%. Nanofibrous polybenzimidazole (PBI) membranes were prepared from a fresh solution by the electrospinning instrument (Cersum s.r.o., Liberec, Czech Republic) depicted in Figure 1. This setup consists of a steel multi-jet spinning electrode (24 nozzles) and a stainless-steel plate as the collecting electrode. The high voltage electrospinning electrode (multi-jet head) with +80 kV DC enabled the preparation of the nonwoven membrane with the width of 2 mm, revealing sufficient cohesion of individual nanofibers. The prepared electrospun membranes were dried in air (Elektrické pece Svoboda, Světice, Czech Republic) at 300 °C for 8 h to a constant weight.

Zirconia (ZrO₂) nanoparticles (~45 nm) were purchased from SRL. Poly [(vinylidene fluoride)-co-hexafluoropropylene] (PVDF-HFP) (Kynar flex 2801) was procured from Arkema Acetone, dimethylacetamide and Lithium hexafluorophosphate (LiPF₆) were purchased from Sigma-Aldrich. Ethyl carbonate (EC) was procured from Alfa Aesar and Dimethyl Carbonate (DMC) from Merck. All the chemicals are of analytical grade and used without any further purification.