Medical Nanotechnology and Nanomedicine

Harry F. Tibbals

• Publisher: CRC Press
• Year: 2017
• Print ISBN: 9781439808740
• eBook ISBN: 9781351834148
• Edition: 1
• Topic: Medicine
• Subtopic: Biotechnology in Medicine

Considering the fluid nature of nano breakthroughs—and the delicate balance between benefits and consequences as they apply to medicine—readers at all levels require a practical, understandable base of information about these developments to take greatest advantage of them. Medical Nanotechnology and Nanomedicine meets that need by introducing non-experts to nanomedicine and its evolving organizational infrastructure.

This practical reference investigates the impact of nanotechnology on applications in medicine and biomedical sciences, and the broader societal and economic effects. Eschewing technological details, it focuses on enhancing awareness of the business, regulatory, and administrative aspects of medical applications. It gives readers a critical, balanced, and realistic evaluation of existing nanomedicine developments and future prospects—an ideal foundation upon which to plan and make decisions.

Covers the use of nanotechnology in medical applications including imaging, diagnosis and monitoring, drug delivery systems, surgery, tissue regeneration, and prosthetics

Part of the Perspectives in Nanotechnology series—which contains broader coverage of the societal implications of nanotechnology—this book can be used as a standalone reference. Organized by historical perspective, current status, and future prospects, this powerful book:

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• Explores background, definitions and terms, and recent trends and forces in nanomedicine

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• Surveys the landscape of nanomedicine in government, academia, and the private sector

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• Reviews projected future directions, capabilities, sustainability, and equity of nanomedicine, and choices to be made regarding its use

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• Includes graphical illustrations, references, and keywords to reinforce concepts and aid further research

In its assessment of alternative and sometimes conflicting concepts proposed for the application of nanotechnology to medicine, this book surveys major initiatives and the work of leading labs and innovators. It uses informative examples and case summaries to illustrate proven accomplishments and imagined possibilities in research and development.

Part I
Perspectives

1
Nanomedicine: Scientific Basis and Societal Implications

How does nanomedicine separate itself from other traditional research fields? Is it really different from research that scientists conducted a decade or more ago?

Thomas J. Webster, Division of Engineering and Orthopedics, Brown University [1]

1.1 Introduction

To understand the place and significance of nanomedicine, one must first understand both medicine and nanotechnology.

The English word medicine has its roots in the Greek µέδoµαι—the verb (medome), meaning “to care for.” In both Greek and English usage, the word for care also holds the meaning of “to think deeply.” It also means “to execute artfully,” which for us should emphasize that medicine is as much an art as a technology.

The modern word nanotechnology was derived from the term nano, which is the prefix used in the International System of Units (SI) for one billionth of a meter, or 10^-9 m. The prefix nano, like milli-(one thousandth) and micro-(one millionth), was adopted by the SI standard from Greek and Latin root words [2]. Nano comes ultimately from the Greek word for dwarf, and is also related to the Spanish word niño (feminine: niña)—”young child.” The term was coined by Professor N. Taniguchi in 1974, who defined nanotechnology as “the processing of separation, consolidation and deformation of materials by one atom or one molecule,” thus providing a conceptual focus for a number of technological trends that were emerging with increasing importance [3].

1.2 Medicine

Medicine is the knowledge and practice of maintaining and restoring health. Health is the state of a person, an organism, or an organ in which its systems are able to perform their functions without failure in the face of external threats and internal complications. Living systems are constantly meeting challenges such as stress, injury, malformation in development, genetic errors, invasions by viral, bacterial, and parasitic agents, cancer, degeneration, and challenging normal life events such as pregnancy and delivery, puberty, menopause, aging, and death. It is the goal of medicine to support, maintain, and restore productive functioning of life while minimizing suffering and doing no harm. The roots of medicine lie in our empathy for our fellow creatures, starting with our fellow human beings. Medicine is essentially a human art, which is supported by observation, evidence, recording, and passing on of knowledge and experience, training, and standards. “There is no one division of medicine by which we know and another by which we act” [4]. Medical science is inseparable from medical practice, as the ultimate significant observation is the outcome for a patient.

Medical science is the application of scientific methods to the study of living systems with the goal of improving medical practice. Medical science is based on any scientific or technological discipline that can contribute knowledge and techniques that advance the practice and understanding of medicine. These have historically included anatomy, physiology, chemistry, physics, engineering, and other disciplines. The development of medical science is inextricably involved with other sciences. The student who aspires to work in medical practice or research must be prepared with a solid base in multiple disciplines relevant to human health. Increasingly, these disciplines will include aspects of nanoscience and nanotechnology as applications to medicine emerge.

Modern understanding of health is based on the concept of regulation of metabolism by a complex network of molecular-based communication mechanisms known as cell signaling that governs basic cellular activities and coordinates cell actions. Cells in the body perform their life cycle functions in part by genetic programming, but also by responding to molecular signals generated within the cell and received through receptors on the cell membranes. These networks respond to, are controlled by, and can be disrupted by processes that take place on the electrical, molecular, macro-molecular, and supramolecular scales. The latter are the domain of nano-technology, where current advances are offering applications for medicine.

Healthy organisms tend to maintain homeostasis, from the Greek words meaning “like or same” and “still or static.” Homeostasis is defined as the stable state controlled by a system of feedback: the system reacts to changes sensed in its state and/or environment to counter influences that tend to destabilize it or divert its development from the normal path. For example, body temperature, blood pressure, levels of carbon dioxide in the lungs and tissues, and the osmotic pressure within cells are homeostatically regulated. Living organisms and systems as a whole are not static: they undergo growth, development, and death in their normal life cycle. Health must be considered as a dynamic rather than a static process, by which a healthy cell or organism responds appropriately to environmental and developmental challenges. Medical science advances the understanding of how these responses are regulated through a complex network of molecular and supra-molecular interactions.

Medical science draws upon engineering concepts and methods to create its own unique models for understanding biological networks as not only chemical but also physical and structural—as complex machinery with subtle control systems acting through specific detailed interactions at the macromolecular and nanoscale level. This approach underlies medical nano-science, a perspective that gives us a framework to model, understand, and intervene in living processes at the level of supramolecular machinery with selectivity and precision [5].

1.3 Nanotechnology

Nanotechnology is a new way of looking at how we manipulate and utilize matter on a very small scale—the nanoscale, or 10^-9 m. Nanoscale dimensions lie between the size of atoms and small molecules (measured in angstroms = 10^-10 m), and familiar microscopic and submicroscopic entities such as biological cells and the features fabricated on electronic microchips, whose dimensions range from hundreds of microns to fractions of a micron (=10^-6 m).

The application of nanoscale entities and phenomena is not especially new. Artisians, technologists, and scientists have utilized nanoscale particles and filters for many purposes for centuries. Physics and chemistry have dealt with matter on extremely small scales for more than 200 years. What makes nanotechnology new is the scientific investigation and technical exploitation of properties that depend uniquely on the nanoscale. And what is enabling the revolutionary impact of nanotechnology is the new capability for precise observation, measurement, and manipulation of individual nanoscale units of matter, opening a new frontier of human knowledge and resources for all kinds of applications.

Over the past 25 years, due to the development of new techniques and tools, precisely controlled manipulation of matter at the nanoscale has become possible for the first time. The emergence of nanotechnology has impacted the traditional domains of chemistry, biology, and medicine. Nanotechnology is now an exponentially growing focus of research and development.

The scientific basis of this interdisciplinary field is being conceptualized into a study of nanoscience: the science of the surprisingly unique and peculiar phenomena describing the behavior of matter on the nanoscale, as feature and particle sizes approach the dimensions of a few tens to a few thousands of atoms. These phenomena emerge from the high surface-to-volume ratios of nanoparticles, the predominance of surface energy interactions over bulk and chemical energetics which results, the interaction of nanoparticles with light of nanoscale wavelengths, and the interactions between particles— dependent primarily on surface, steric, and entropic factors determined by the shapes and surface properties of the particles and their absorbed layers of solutes and ligands—especially in water. These surface interactions can even produce surprising effects in macroscale objects when their interfaces possess nanoscale features.

Each advance in understanding phenomenon on the nanoscale leads to new opportunities for exploitation with new tools, materials, techniques of assembly (and controlled self-assembly), and devices such as sensors and nano-actuators. It is hardly an exaggeration to say that nanoscience and nan-otechnology open an entire new world for exploration and exploitation, possibly launching a new age of economic, scientific, and social development.

The new opportunities opened by nanoscience are especially significant in the biological and life sciences, because, as we are beginning to understand, so many of the critical, intriguing, and uniquely powerful properties of living systems depend on nanoscale phenomena. Hence, it is already evident that nanoscience and nanotechnology will be particularly important to medicine, yielding new understandings and capabilities.

1.4 What Is Nanoscience and Where Does It Fit in the Sciences?

1.4.1 Definition and Scientific Basis

Nanoscience is the science of the phenomena peculiar to matter on the scale from 1 to several hundred nanometers (10^-9 m). Individual atoms are on the order of 10^-10 m (=1 Å). Down to a few tenths of a micrometer (10^-6 m = the micro scale), the properties of matter are not much different from those familiar at the macroscopic scale (>10^-4 m). At the macroscopic scale, the bulk properties of matter predominate over the surface properties, but at the nanoscale, new phenomena emerge.

Bulk macroscopic material presents a sharp interface to its environment, when it comes to interactions with other material and energy, whether solids, liquids, gases, or electromagnetic radiation, including light. This is the domain of classical physics. On the other extreme, interactions at the atomic scale are characterized by quantum physics and chemistry, which govern the behavior of chemical bonds, atomic and molecular spectra, photochemistry, and chemical reactions.

Nanoscience is the science of matter and energy in the transitional scale between the atomic and macroscopic states of aggregation of atoms. Some unique properties of matter emerge when features are on the nanoscale. Understanding and appreciation of these properties open new opportunities, which have been ignored or poorly understood until the past few decades because the technology was not available to explore and manipulate matter at the nanoscale.

By the middle of the twentieth century, the science of matter on the atomic and subatomic scale—chemistry and physics—had advanced by brilliant and intricate experiments and deductions based on observations of interactions at the macroscale (large numbers of atoms and molecules undergoing chemical reactions, and interactions between matter and energy—heat, light, and radiation). Micro- and cell biology and genetics were giving life scientists tantalizing glimpses and suggestions of the intricate precision of macro-molecular mechanisms that must be the basis for life. But the tools were not available to observe and manipulate particles and features on the nanoscale until relatively recently, and the range and power of such nanotools are still being rapidly developed and improved.

As chemists worked out an understanding of the behavior of matter, the description and modeling of isolated pairs of atoms or molecules came first, and was then generalized with statistical mechanics and kinetics to theories that successfully described the bulk behavior of very large numbers of molecules, all acting in similar ways in an averaged environment. Having to take into account the specifics of atomic and molecular arrangements on the nanoscale gets one into formidable complexity, except where the arrangements are repetitive and highly regular, as in crystals, polymers, and minerals...

Table of contents

• Cover Page
• Title Page
• Copyright Page
• Contents
• Foreword
• Preface
• Acknowledgments
• Author
• Part I Perspectives
• Part II Beginnings of Medical Nanotechnology
• Part III Future Directions and Transformations
• Index