Animal ultrasound microbubble contrast agentIt is a micrometer sized bubble wrapped in an inert gas (such as perfluoropropane, sulfur hexafluoride) with a liposome shell. Its diameter is usually 1-10 microns, similar in size to red blood cells, and it can freely pass through capillaries. The core principle is to generate nonlinear signals (such as harmonics) through the vibration of microbubbles under ultrasound, significantly enhancing the contrast between tissue and blood vessels, thereby improving the clarity and resolution of ultrasound images.

　　Animal ultrasound microbubble contrast agentMain types and components:

Basic type: with phospholipids or polymer materials as the shell, wrapped in inert gases such as perfluorocarbons (such as octafluoropropane C3F8) or sulfur hexafluoride. This type of contrast agent forms a stable monolayer through the self-assembly ability of the phospholipid layer, slowing down gas diffusion and prolonging circulation time in the body (usually 6-15 minutes).

Targeted type: Selective recognition and binding of pathological tissues or specific cell surface markers (such as endothelin CD105, integrin α v β 3) through surface modification of targeted molecules (such as antibodies, peptides). For example, directly attaching RGD peptides to the surface of microbubbles can target and activate glycoprotein IIB/IIIA receptors on platelets, improving the sensitivity of thrombus detection.

Drug loading type: hydrophobic drugs are loaded onto the outer shell, or hydrophilic drugs are encapsulated in the core of microbubbles. Through ultrasound mediated cavitation, targeted drug release can be achieved when microbubbles rupture, reducing systemic toxicity. For example, drug loaded microbubbles combined with ultrasound cavitation can selectively release chemotherapy drugs at the tumor site.