Urokinase

Nattokinase fermentation broth was made by our laboratory. Food‐grade modified starch was purchased from Juntao. Food‐grade β‐dextrin was got from Tianzhao. Urokinase (1,280 IU), thrombin (190 bp), and fibrinogen were purchased from Yuanye.

B. subtilis BSNK-5 was identified in our laboratory and stored at −80 °C in a refrigerator with 15% glycerol (w/v). S. lactis (BNCC 190729) and Micrococcus luteus (BNCC 102589) were purchased from BeNa Culture Collection. S. clavuligerus (ATCC 27064) was purchased from Shanghai Guyan Industrial Co., Ltd. (Shanghai, China). The yeast extract and tryptone were purchased from Oxoid (LP0021, LP0042B, Beijing, China). DeMan Rogosa and Sharpe (MRS) medium was purchased from AOBOX (02-293, Beijing, China). The Nutrient Broth (NB) medium was purchased from Qingdao Hope Bio-Technology Co., Ltd. (HB0108, Qingdao, China). The malt extract was purchased from Solarbio Science & Technology Co., Ltd. (M8130, Beijing, China).
Urokinase and nisin were purchased from Yuanye Bio-Technology Co., Ltd. (9039-53-6, 1414-45-5, Shanghai, China). CA was purchased from the National Institutes for Food and Drug Control (6SNT-6F3D, Beijing, China).
The beef extract (BE) was purchased from AOBOX (01-009, Beijing, China). SP was purchased from Solarbio Science & Technology Co., Ltd. (1008C052, Beijing, China). SMP, SPC, SPI, and SPH were supplied by Shandong Vandefu Co., Ltd. (Shandong, China).

Urokinase (BR, 50,000 u/g) was purchased from Shanghai YuanYe Biotechnology Co., Ltd, China, and the drug was diluted to a solution of 2500 u/ml with saline (CAS #7647-14-5, Sigma Company, China), (the LD50 of Urokinase is 1000 u/g). When LSMI monitoring suggested thrombosis, 250 u/25 ​g units of Urokinase was injected from the tail vein for thrombolysis after 20–30 ​min 2.2.3 IPN@UK thrombolysis.
The preparation method was as described above. When LSMI monitoring suggested thrombosis, 0.1 ​ml/25g (body weight) of the prepared magnetic nanoparticle-Urokinase solution is injected from the tail vein 20–30 ​min later to lyse the thrombus.