Preface

More than 50 years after Lehn, Pederson and Cram did the pioneering work which started the field of supramolecular chemistry, the concepts developed to understand ‘chemistry beyond the molecule’ have come to underpin much of biological imaging and diagnosis. This is, in part, because biology is an extremely sophisticated form of supramolecular chemistry: it represents an area in which the interactions between molecules (or ions) are governed by the association of molecules, the displacement of solvent and the change in form and function that characterises intermolecular interactions. This combines with sophisticated molecular recognition and molecular machinery to run systems that can operate off equilibrium for the whole lifetime of an organism.

The small interactions that underpin the action of this highly evolved machinery can be exploited to begin to understand biology. Within 20 years of the foundation of supramolecular science, its principles were being exploited in understanding the behaviour of healthy and diseased systems. In 1985, Roger Tsien (Nobel Laureate in Chemistry, 2008, and one of the founders of molecular imaging), developed calcium chelating systems that could be used to measure calcium concentrations quantitatively in vivo. These systems almost represent a field in themselves, and have contributed to the rapid development in our understanding of molecular physiology in the closing years of the 20th century. Around the same time, contrast agents for molecular imaging of disease were entering clinical and preclinical use: magnetic resonance imaging (MRI) agents were first licensed for clinical use in 1988, while the widespread use of medical radioisotopes in tomographic imaging also dates from the 1980s.

As supramolecular science comes to maturity, there is still much to do in the field of imaging. More than 30 years of application have revealed both the potential and the pitfalls of contrast enhanced imaging, while new developments and technologies have dramatically expanded the potential scope of the field.

In this volume, we have gathered a series of monographs on areas of current interest in the field. While they are not exhaustive, they reveal the enormous potential for further advances as we move towards the personalisation of medical diagnosis and treatment. The following chapters provide a range of views of where we are and where we are going. They cover all length scales from the molecular to the whole person. Super-resolution microscopy can now provide detailed information about the construction and function of biological systems (Chapter 3), while optical imaging techniques (Chapter 2) have moved to be able to bridge the gap between the diffraction limit and the mm resolution limit of whole-body imaging techniques such as MRI (Chapters 5 and 6) and radioisotope tomography (Chapter 4). In addressing the challenge of smart contrast, we also explore the scope for tissue- and disease- specific imaging through targeting (Chapter 1) and through development of effective methods for imaging in the brain (Chapter 7). We also explore how the advent of nanoscience creates new opportunities that cross modalities (Chapters 8 and 9).

We hope that you enjoy reading about these developments as much as we have.

Stephen Faulkner

Thorfinnur Gunnlaugsson

Gearóid M. Ó Máille