Glycerol diglycidyl ether

HAp ultrafine microparticles (22.5 g, 2 µm-diameter; Himed) were combined with 10% (wt/v) Brij (Sigma) (27 mL) in ultrapure water and polyethylenimine (Sigma) (4 mL) and vortexed overnight to form a foam. The foam was thoroughly mixed with glycerol diglycidyl ether (Sigma) (1 mL) and scooped into rectangular silicon molds, sealed in plastic bags, and placed in a 40 °C oven overnight to allow the blocks to solidify. Promptly after 18 h, the HAp blocks were gently removed from the molds, again sealed in plastic bags, and frozen for at least 2 h at −80 °C. After the blocks were fully frozen, they were lyophilized for 2 days to stabilize them. The HAp blocks were then milled into a dome-shaped geometry to mirror the ovine medial femoral condyle. To do so, tool paths were developed in the computer aided machining (CAM) software (Esprit), and the blocks were milled using a Computer Numerical Control (CNC) ball mill (1/8 in.; Fig. 7). The resulting anatomically shaped HAp ceramics were sintered in an oven (Nabertherm P330) using the following scheme: The temperature increased from room temperature (25 °C) to 600 °C at 1 °C/min. This temperature was held for 1 h to burn off the epoxy within the ceramics. The temperature was then increased to 1310 °C at 4 °C/min and held for 8 h before returning to room temperature.

A naringenin (natural, 98%, MW: 272.25 g/mol, Sigma Aldrich, Shanghai, China,) reaction with glycerol diglycidyl ether (GDE) crosslinker was performed according to the method described by Sahiner [26 (link),27 (link)] with minor modifications.
In the first step, a solution of naringenin was prepared by dissolving 1 g in 10 mL of 1 M NaOH (ChemPur, Piekary Śląskie, Poland). Dissolving the naringenin in NaOH was one of the elements of the reaction, which was aimed at increasing the solubility of this compound, as well as opening the rings before polymerization (cross-linking reaction). In the next step, 4 mL of naringenin solution was added to 150 mL of a 0.1 M solution of L-α-lecithin (from soybean, ≥99%, MilliporeSigma, Darmstadt, Germany) in cyclohexane (96%, pure. P.A., ChemPur, Poland). Then, the mixture was stirred for 2 h at 1000 rpm at room temperature. After that time, glycerol diglycidyl ether (technical grade, Sigma-Aldrich, Darmstadt, Germany) was added in an amount of 100 mol% with respect to naringenin used. The solution was stirred for 2 h at 1000 rpm and 25 °C. Poly(naringenin) was washed twice with cyclohexane by centrifugation (6000 rpm, 20 °C) and dried at 35 °C for 72 h in a dryer.

High-viscosity sodium carboxymethyl cellulose (DS = 0.9) with a molecular weight average of 700 kDa, four diglycidyl ethers (Table 1; Figure 1); glycerol diglycidyl ether (Mn 204 g/mol), poly(ethylene glycol) diglycidyl ether (Mn 500 g/mol), and poly(propylene glycol) diglycidyl ether (Mn 380 g/mol and Mn 640 g/mol), high purity D-(+)-cellobiose, and poly (ethylene glycol) Mn 400 g/mol) were purchased from Sigma-Aldrich. Sodium hydroxide (NaOH) pellets were purchased from Merck and made up into a 0.1 M solution to alkalize the CMC.