The fundamental assumption underlying most studies of metamorphic rocks, including the examples described in Chapter 1, is that their mineral assemblages reflect the physical conditions of pressure and temperature which prevailed at the time when they grew. This assumption is grounded in numerous field studies that have shown that the mineral assemblages in any particular rock type vary systematically and predictably across an area. Additionally, rocks of the same composition always appear to develop the same mineral assemblage when they are subject to the same metamorphic conditions. These observations are the basis for applying the theory of chemical equilibrium to metamorphic rocks. This chapter outlines the information that can be gleaned by treating rocks as equilibrium chemical systems along with the limitations and pitfalls of so doing.

Nanomedicine, like conventional medicine, has two aims: to diagnose the disease, as accurately and as early as possible, and to deliver the most efficient treatment possible. Unlike conventional medicine, it uses nanomaterials and nanotools to achieve this. We saw in Chapter 8 the way in which nanotechnology advanced the field of biosensors, and we now look at some of the concepts behind the design of drug nanocarriers and nanocomposites for tissue engineering, as well as some challenges that still need to be overcome. In the core of bionanotechnology is the exploration of interactions between engineered nanomaterials with biomolecules and cells. Such studies are not only important to help the design of biocompatible materials, but also to assess the environmental impact of man-made nanosized structures. Nanotoxicology has emerged as an independent research discipline that studies the toxicology of nanostructures, which as we have seen in previous chapters have a unique set of properties due to their small size. Some of the protocols to assess the toxicological profile of new nanomaterials, as well as existing regulations and risk assessments, will be briefly covered in the last part of the chapter.

Characterisation of nanomaterials, whether this refers to their physicochemical properties or their interactions with biomolecules and cells, requires a combination of analytical strategies. Before we explore some of the main instrumental methodologies for analysis of bionano constructs and devices, it is important to define the main questions we are trying to answer using analytical techniques (Figure 5.1).

In 1599, when Galileo was starting to make a name for himself at the University of Padua, a young Cambridge graduate, William Harvey (1578–1657), arrived there to study medicine. Padua was one of the two most prestigious medical faculties in Europe (the other being Leiden), and known to admit non-Catholic students, providing them with special colleges, so an Englishman aspiring for a medical career in the metropolis was all but obliged to make the journey.

What happened to Greek knowledge? Not just the astronomy of Eudoxus, Eratosthenes and Hipparchus, but the natural philosophy of Aristotle and his disciples with its forays into what we’d call botany and zoology; the medicine of Hippocrates and Galen (to whom we’ll return in Chapter 8); the geography of Ptolemy; the mathematics of Euclid and Archimedes and much more – all that knowledge the longing memory of which Raphael captures so marvelously at the beginning of the sixteenth century (Figure 4.1) – and of which we now have only fragments or recollections of.

This is the Gothic cathedral, the marvel that inspired Ormond’s poem. The one in the picture (Figure 1.1) is perhaps the grandest of them all: the Notre Dame cathedral at Chartres, south-west of Paris. It is a breathtaking accomplishment: 130 meters in length, it would cover a Manhattan block and a half; its vaults are 37 meters in height, higher than a modern ten-story building; its southern, Romanesque tower is 107.5 meters tall, and the northern, Jehan de Beauce tower, 114 meters – a 30-storey skyscraper of “hewn rock … hoisted into heaven.”

Ever since metamorphic rocks were first recognised, geologists have sought to understand the conditions under which they formed and hence learn something about how rocks are buried and reworked inside the Earth. The recognition that many metamorphic mineral assemblages formed close to equilibrium, discussed in Chapter 2, opened up the possibility that metamorphic conditions could be determined once the conditions for equilibrium were quantified. In the course of the twentieth century, it gradually became possible to do this, and hence to determine the depths and temperatures at which specific rocks were formed. As we saw in Chapter 1, the variation of temperature with depth can be characteristic of particular tectonic settings and so P–T values for metamorphism have become essential for understanding the tectonic settings in which ancient metamorphic belts developed. The development of new experimental and analytical techniques and improved computer modelling approaches has meant that our ability to make accurate and precise estimates of the conditions at which particular metamorphic mineral assemblages can exist at equilibrium has improved rapidly. In this chapter we first introduce the underlying principles which enable us to make estimates of temperatures and pressures in metamorphism. We then introduce a number of approaches to estimating metamorphic conditions, ranging from classical qualitative methods (which are valuable during fieldwork) to comparison with experimental results and the application of thermodynamic databases. In Chapters 4–6 we present examples of how some of these approaches can be applied to a variety of rock types.

Bionanotechnology is an interdisciplinary field at the intersection of nanotechnology and biology. Whereas nanotechnology provides tools and platforms for exploration and transformation of biological systems, biology is a source of inspiration and building blocks, all with the aim to design new materials and devices.

Metapelitic rocks are derived from clay-rich sediments. They are of particular importance for studies of metamorphism because they develop a wide range of distinctive minerals that help constrain peak P–T conditions.