Durapore 0.45 μm

Scaffolds were prepared as previously published 18. Briefly, nonwoven polyglycolic acid scaffolds are rolled over a 1.5‐mm outer diameter glass capillary tube from a flat sheet (2‐mm sheet thickness, 60 mg cm⁻³ bulk density; porosity >95%; Concordia Fibers, Coventry, RI.
http://www.concordiafibers.com). The entire cylinder is sealed with 5% poly‐L‐lactic acid (Durect Corporation, Cupertino, CA,
http://www.durect.com) in chloroform (Sigma‐Aldrich, St. Louis, MO,
https://www.sigmaaldrich.com). After sterilization with 80% ethanol, the polymers were coated with 0.4 mg/ml type 1 collagen solution (Sigma‐Aldrich) for 20 minutes at 4°C, rinsed with phosphate buffered saline (Thermo Fisher), and stored dry at room temperature in a desiccator (Durapore 0.45 μm; Millipore, Billerica, MA,
http://www.emdmillipore.com) to avoid premature hydrolysis, degradation or contamination. Fresh cut constructs (3 mm) were used for implantations 18.

The experiments were performed in a three-neck, round-bottom flask equipped with a reflux condenser placed in a heating plate equipped with temperature control (IKA C-MaHS7, Staufen, Germany). Typically, furan (0.71 g, i.e., 10.5 mmol) was added to acetic anhydride (5.5 g, i.e., 52.5 mmol), obeying a molar ratio between substrates and the acylating agent equal to 5. Then, 150 mg of zeolite samples was added and heated to 80 °C. Periodically, less than 0.5 mL of the samples of the reaction mixture was taken using a hypodermic syringe (Millipore Swinnex support with a Millipore Durapore 0.45 μm). Upon quenching in an ice bath, each aliquot was analyzed in a gas chromatograph (Perkin Elmer Auto System, Norwalk, CT, USA) with an FID detector, using N₂ as a carrier gas in a 30 m DB-5MS capillary column (Agilent, Santa Clara, CA, USA) The temperature of the GC injector was 250 °C, and it was 275 °C for the detector. The GC oven for the analysis started at 45 °C for 5 min, followed by a temperature increase of 10 °C min⁻¹ until 200 °C before staying at this temperature for 10 min. All products and unconverted reactants were identified through comparison of the retention times with previously injected standards, and the signals were integrated using DataApex Clarity 9.0 version Software (DataApex, Prague, Czech Republic).