3.4. Loading of Aspirin (Asp)

Dissolve 10 mg of aspirin in 5 mL of PBS buffer, then add 5 mg of MSN and magnetically stir for 12 h. MSN loaded with aspirin was centrifuged and freeze-dried for storage. The absorbance of the centrifuged supernatant at 222 nm was measured using an Ultraviolet spectrophotometer (Max M4, Meigu Molecular Instruments Co., Ltd., Shanghai, China). The content of Asp in the supernatant was calculated using the standard curve method. The loading number of aspirin in MSN@Asp was determined by the difference in aspirin content before and after.

Replace MSN with MSN@Asp, and prepare PDA-MSN@Asp and Gal-PDA-MSN@Asp according to Section 2.3.