Divinylbenzene

Divinylbenzene (DVB, 80 wt.%), methylacrylate (MA, >99%), benzoyl peroxide, and TC were obtained from J&K Chemical Co., Ltd., China. Tetraethylenepentamine, anhydrous ferric chloride, 1,2-dichloroethane, sodium chloride, hydrochloric acid, sodium hydroxide, and cupric nitrate trihydrate were all analytical reagents and purchased from Sinopharm Chemical Reagent Co., Ltd (China). DVB and MA were passed through a strong base anion exchange resin column to remove the inhibitors prior to use.

Glycidyl methacrylate (GMA) was obtained from TCI Company (Shanghai, China). Divinylbenzene was obtained from J&K chemical (Beijing, China). 1-Ethyl-3-(3-dimethyllaminopropyl) carbodiimide hydrochloride (EDC·HCl) and N-Hydroxysuccinimide (NHS) were purchased from Shanghai Medpep corporation (Shanghai, China). Bovine albumin (BSA), Hemoglobin from bovine blood (Hb), Cytochrome C (Cyt C) were obtained from Aladdin chemical corporation (Shanghai, China). Polyvinyl pyrrolidone (PVP K-30), 2,2′-azobis-(isobutyronitrile) (AIBN), ethylenediamine (EDA), anhydrous morpholine ethanesulfonic acid, and other chemicals were received from Beijing Chemical Factory (Beijing, China). Cell Counting Kit-8 (CCK-8) was received from Dojindo Laboratories, Kumamoto, Japan. Human pulmonary epithelial cells were purchased from InvivoGen (San Diego, CA, USA) and grown in Dulbecco’s modified Eagle’s medium (Sigma-Aldrich, St. Louis, MO, USA) containing 10% (v/v) fetal bovine serum, 50 units/mL penicillin, 50 mg/L streptomycin, 100 μg/mL normocin, and 10 μg/mL blasticidin. All chemicals were used without further treatment. Deionized water used in polymerization and characterization was distilled and purified by Aqua Pro (Chongqing, China).

Gelatin (0.8 g, Aladdin, Shanghai, China) was dissolved in deionized (DI) water (200 mL) at 60 °C for 30 min, and subsequently, styrene (20.0 g, J&K Scientific, Beijing, China), divinylbenzene (2.4 g, J&K Scientific), benzoyl peroxide (0.3 g, Sigma-Aldrich, Shanghai, China), and polyvinyl alcohol (1.1 g, Adamas, Shanghai, China) were sequentially added to the aqueous phase under continuous stirring. The mixture was heated to 80 °C and stirred for 2 h, heated to 88 °C for 2 h, and then solidified at 95 °C for 8 h. Finally, the obtained PSDB balls were washed with DI water and dried for 12 h at 60 °C in a vacuum oven [49 (link)].