2 3 3 trimethylindolenin

Silicone hollow cylinders (L:22 mm, ID: 4 mm, WT: 0.5 g) were cut from extruded silicone tubing (Nusil MED-4020). Carbon dioxide (N48) was purchased from Air Liquide Denmark. HEMA (97%,), 4-(dimethylamino)pyridine (DMAP), PEGMEA (Mn 480), dicyclohexylcarbodiimide (DCC), 2,3,3-trimethylindolenin 98%, tert-butyl methyl ether (TBME), 2-hydroxy-5-nitrobenzaldehyde, tetrahydrofuran (THF), 98% ethylene glycol dimethacrylate (EGDMA), 3-iodo-propanoic acid, ethyl methyl ketone, piperidine, doxycycline hyclate (DOX) and ethanol (99.8%, EtOH) were purchased from Sigma-Aldrich. The monomethyl ether hydroquinone (MEHQ), the polymerisation inhibitor of HEMA and PEGMEA, was removed as described previously [48]. Diethyl peroxydicarbonate (DEPDC) in hexane (0.2 M) was prepared as described by Xu et al [56] and used as initiator.

2.1. Materials and chemicals. Silicone hollow cylinders (L:22 mm, ID: 4 mm, WT: 0.5 g) were cut from extruded silicone tubing (Nusil MED-4720) and carbon dioxide (N48) was supplied by Air Liquide Denmark (Copenhagen, Denmark). 2-hydroxyethyl methacrylate (97%, HEMA), poly (ethylene glycol) methyl ether acrylate Mn 480 (PEGMEA), butyl methacrylate (BMA), 2,3,3-Trimethylindolenin 98%, 2-hydroxy-5-nitrobenzaldehyde, acetonitrile, diethyl ether, dichloromethane (DCM), hexane, potassium hydroxide, triethylamine, methacryloyl chloride, 2-bromoethanol, 98% ethylene glycol dimethacrylate (EGDMA), tetrahydrofuran (THF), doxycycline hyclate, curcumin, dopamine hydrochloride and ethanol (99.8%, EtOH) and 3-(3,4-Dihydroxyphenyl)-L-alanine (L-DOPA) were purchased from Sigma-Aldrich. Removal of the monomethyl ether hydroquinone (MEHQ) inhibitor from HEMA and PEGMEA and their purification was done as described previously 53 (link) . Diethyl peroxydicarbonate (DEPDC) in hexane was prepared as described by Xu et al 56 (link) and used as initiator for radical polymerization.