Glycoprotein (GP) IIb/IIIa
GPIIb/IIIa receptor, also known as integrin αIIbβ3 and CD41/CD61, is the most abundant receptor on the membrane surface of platelets with 60,000 to 80,000 receptors per platelet. The expression of GPIIb/IIIa is platelet-specific and upon platelet activation, the GPIIb/IIIa receptor undergoes a conformational change from a low affinity to a high affinity receptor for its natural ligand fibrinogen/fibrin. The arginine-glycine-aspartic (RGD) peptide mimics the binding epitopes of GPIIb/IIIa’s natural ligand fibrinogen, and has therefore been used for the detection of vascular thrombosis via a range of imaging technologies (Schumann et al., 2002; Klink et al., 2010; Zhou et al., 2011; Hu et al., 2012; Unger et al., 2014; Guo et al., 2015; Kang et al., 2015; Rix et al., 2016). Hu et al, demonstrated that microbubbles conjugated with cyclic RGD peptides, facilitated the visualisation of thrombosis via molecular ultrasound imaging (Figure 5) (Hu et al., 2012). In this study, the authors demonstrated that brightness-mode ultrasound imaging could be used to visualise the echogenic thrombi in the abdominal artery of a rodent model. Colour Doppler imaging was also used to confirm the vascular stenosis created by the thrombi (Hu et al., 2012).