The Preparation And Targeting Assessment Of RGDS Peptides Conjugated Lipid Microbubble

Background and objectiveMicrobubbles(MB) ultrasound contrast agent (UCA) is clinically applied to enhance the ultrasound scattering of blood flow. It featured with noninvasive, real-time blood perfusion imaging, no side effects and promising wide application. However, the UCA used today, is a non-specific blood pool contrast agent, and the contrast imaging is also non- specific. Thus, targeted UCA, which could potentially detect specific target disease, became world wide interested.Recent interests of contrast specific targeted imaging included but not limited to thrombosis, artheriosclerosis (AS), tumor angiogenesis and inflammation. The targeted contrast imaging could potentially find specific lesions or tissues, which otherwise be difficult to distinguish from surrounding, and this improves the sensitivity and specificity of ultrasound diagnosis. Several targeted ultrasound contrast agent (TUCA) for tumor angiogenesis, thrombosis and AS are currently under development by several American research groups. There are some methods that enable MB to acquire the targeting ability. Firstly, MB can be retained at some lesion by electrostatic or weak non-covalent interactions on the shell. Secondly, MB shell can be incorporated with a ligand or a bioactive substance, which could find the specific antigen. In addition, once microbubble was conjugated with a monoclonal antibody by some bio-bridge connection, which could potentially has both specific imaging and therapeutic purpose.The cardiovascular thrombosis caused by thrombus formation in artery or vein, is a common clinical event and a major reason of death. The need to improve the diagnostic accuracy of ultrasound for detecting vascular or intracardiac thrombi and its involvement has led to the development of thrombus-targeted MB. There are some alternative methods like MRI and angiography, but expensive and invasive.The RGDS microbubble acquired thromus targeting ability by recognizing the glycoprotein IIb/IIIa (GPIIb/IIIa) receptors on activated platelets. GPIIb/IIIa compounds are...