Polyethylene Scaffold Biocompatibility

Tissue-culture polyethylene (CPE) and ordinary polyethylene (PE) were provided by NEST Biotechnology Co., Ltd., Wuxi, China. Hydroxyl-terminated poly(N-isopropylacrylamide) (PNIPAAm-OH) was prepared in our lab (Scheme S1a). Tannic acid (TA, ≥98%), rhodamine B isothiocyanate (BRITC, 99%), 3-aminopropylthiethoxysilane (APTES, 98%), alkaline phosphatase (ALP, 98%), an ALP assay kit, and DMEM were purchased from Sinopharm Chemical Reagent Co., Ltd., Shanghai, China. Mouse fibroblast cells (L929 cells), phosphate buffer saline (PBS, 99.9%, pH = 7.4), and fetal bovine serum (FBS, 97%) were obtained from Guangzhou Oricell Biotechnology Co., Ltd., Guangzhou, China. Calcein acetoxymethyl ester (Calcein AM) and propidium iodide (PI) were obtained from Solarbio, Beijing, China. Carbon dioxide (CO₂, 99.999%) was supplied by Guangzhou Spectral Source Gas Co., Ltd., Guangzhou, China.