Methotrexate-loaded lipid microbubble as well as preparation method and application thereof

The invention discloses a methotrexate-loaded lipid microbubble as well as a preparation method and application thereof. The methotrexate-loaded lipid microbubble comprises an inert gas/liquid medicine and a shell layer; the shell layer is composed of a lipid derivative of methotrexate and natural phospholipid which are linked through chemical bonds; and the chemical bonds are ester bonds and can be broken in an acid environment and in the presence of esterase so as to blast the shell layer. The methotrexate-loaded lipid microbubble provided by the invention takes a lipid derivative of a covalent bond linked methotrexate drug as a film forming material, and after intravenous injection, the methotrexate-loaded lipid microbubble circulating in blood can be used as an ultrasonic imaging contrast agent, so that real-time monitoring of drug distribution is realized; when the microbubbles reach a treatment area, the microbubbles can be converted into drug-loaded nanoparticles through an ultrasonic targeted blasting