In many cardiac conditions, including heart failure, atrial fibrillation (AF) and myocardial infarction (MI), it is a significant disease feature.
Present imaging techniques of cardiac fibrosis employing magnetic resonance imaging (MRI), have many limitations. However, the use of clever imaging molecules that bind collagen directly could overcome these limitations and allow more sensitive detection of fibrotic heart, resulting in sooner diagnosis and improved management of heart disease.
Under the supervision of Professor Christoph Hagemeyer and Dr.Bee'eri Niego from the NanoBiotechnology group, a collaborative project was conducted at the Australian Centre for blood diseases (ABCD) by final-year doctoral student, Martin Ezeani. New peptide tracers that tightly bind various types of collagen and enable the delivery of imaging agents (such as near-infrared fluorophores and radioactive materials) to the affected heart were tested.
Essential expertise for the study included chemists from Mio21 (Prof Paul Donnelly and Dr Asif Noor – a co-first author), a cardiologist (Dr Sean Lal from the University of Sydney) and Monash’s Dr Karen Alt, who heads the NanoTheranostics at the ACBD.
Senior author Dr Niego said that the project employed this molecular imaging approach to show diffuse cardiac fibrosis in a transgenic mouse model of heart disease (the β2-adrenergic receptor overexpressing mouse). Such type of cardiac pathology is challenging to image using present imaging technologies. It was demonstrated that these peptide probes could enhance the fibrotic areas in diseased human heart tissue.
With promising results emerging also in mouse models of MI and AF, using imaging modalities like positron-emission tomography, this exciting project is on track to produce compatible results for detecting heart fibrosis with significant effects on the treatment of cardiac patients.