Boron trifluoride diethyl etherate

Hydroxyethyl methacrylate, TEA and boron trifluoride diethyl etherate were purchased from MACKLIN (Shanghai, China). Doxorubicin and beta-D-galactose pentaacetate were obtained from Energy Chemical (Shanghai, China). (Hydroxymethyl) phenylboronic acid pinacol ester, 2,2′-azobis(2-methylpropionitrile) (AIBN, 99%), methacryloyl chloride and 2-(dodecylthiocarbonothioylthio)-2-methylpropionic acid were purchased from Aladdin (Shanghai, China). Dialysis bag MD34 (3500 Da) was obtained from Solarbio (Beijing, China). DiR were purchase from MeilunBio (Suzhou, China). MTT solution, 2% phosphotungstic acid and 4′,6-diamidino- 2-phenylindole (DAPI) were obtained from Solaibio (Shanghai, China).
Female mouse 4T1 cells and human breast cancer MDA-MB-231 cells were obtained from American Type Culture Collection (ATCC, USA) and cultured in complete RMPI 1640 medium with 10% fetal bovine serum (FBS) and 1% penicillin-streptomycin. HUVEC were obtained from ATCC and maintained in HUVEC special culture medium (Procell, Wuhan, China) supplemented with 10% FBS and 1% penicillin/streptomycin. The cells were passaged by mechanical dissociation every two days and further cultured in a humidified incubator with 5% CO₂ at 37°C.

All solvents and reagents used in this study are chemically pure. 1,4-Diethoxy benzene was purchased from Tokyo Chemical Industry Co. Ltd., polyformaldehyde and ammonium hydroxide solution were purchased from Shanghai Titan Scientific Co. Ltd (China), ethyl bromoacetate, triphenylphosphine, carbon tetrabromide and s-trioxane were purchased from the Saen Chemical Technology (Shanghai) Co. Ltd, boron tribromide and boron trifluoride diethyl etherate were purchased from Shanghai Macklin Biochemical Co. Ltd. Guests G1 and G2 were purchased from Aladdin Chemical Reagent Co. Ltd (Shanghai, China) and Bide Pharmatech Ltd (Shanghai). All solvents were purchased from Shanghai Titan Scientific Co. Ltd (China) and used directly without further purification. Hosts H1 and H2 were synthesized according to the reported procedures.^{33,34 (link)}