associate director of the Institute for Bioengineering of Catalonia (IBEC)
Research on new principles and techniques in the physical sciences and engineering have enabled countless important discoveries in biology and medicine.
In clinical practice and biomedical research, these contributions have included the harnessing of X-rays and the invention of nuclear magnetic resonance (NMR) for medical imaging and for studying molecular structure; development of the latest nanotechnology applications for molecular or cellular manipulation; and the creation of biochips.
Nanotechnology for medical applications is known as nanomedicine. This interdisciplinary field encompasses both basic research and technology and aims to improve diagnosis, treatment and prevention of diseases and traumatic lesions, while preserving or even improving patients’ quality of life. By gaining knowledge and understanding of the human body at the molecular level, researchers in nanomedicine endeavor to analyze, monitor, repair, rebuild and improve any human biological system.
There are currently three priority areas for nanomedicine applications: improving diagnosis (both in vitro and in vivo); developing more effective systems for drug delivery and dosing; and devising technologies for tissue engineering and regenerative medicine.
In nanodiagnostics, nanodevices are employed to identify diseases or disease risk at the molecular or cellular level. The technology in this area is geared at answering the social and clinical demand for the earliest detection possible. Another goal is to screen patients for their potential to suffer any unwanted side effects from a given drug before it is prescribed to them. Improving diagnostic efficiency is paramount for meeting these objectives. Nanotechnology offers tools to enhance the sensitivity, specificity and reliability of diagnostic methods. It also enables simultaneous measurement of multiple parameters as well as integration of various steps in the analytical process: a sample can be prepared and subsequently detected in a single miniature device.
Thanks to nanotechnology, the devices of the future, computerized and robust, will be so intelligent that they will deliver a multitude of data to doctors, and patients themselves will be able to use them. They will cover currently unmet needs to benefit patients and the healthcare system.
In vitro diagnosis will be performed by biosensors or integrated devices containing multiple sensors. Biosensors contain a specific biological receptor, such as an enzyme or an antibody, which can directly detect a specific substance or determine its concentration, and then translate this biochemical interaction into a quantifiable electronic signal through a transducer. These devices include nanostructures fabricated by lithography that can be coated with biomolecules capable of binding to specific substrates (e.g. proteins, DNA complementary to a given genetic sequence, or basically any molecule that participates in adhesion or in receptor-ligand recognition). Other examples are nanodevices capable of acting as a platform for detecting biomarkers with greater sensitivity than currently available methods; and nanocrystals of semiconducting material, known as quantum dots, which, when coupled to an antibody or another biomolecule, can interact with a target molecule.
Molecular imaging is defined as the in vivo measurement, characterization and diagnosis of molecular or cellular biological processes through images generated by combining traditional medical imaging techniques with new molecular agents.
The quest for safe and effective therapies now demands more than simply having pharmacologically active molecules: the vehicles, support structures, and systems used for encapsulating bioactive compounds have acquired a fundamental role in determining the ultimate success of a given drug. Drug delivery systems have enabled more potent and selective treatments, offering higher efficacy-to-toxicity ratios for current and future drugs. The concept of drug delivery arose in the 1970’s alongside the advent of controlled drug release, when scientists realized that they could improve the therapeutic properties of drugs by incorporating them into a system that enabled their release in a targeted location and at a desired speed. Thus, from the very onset, drug delivery represented a rupture with traditional ideas on drug formulation, dosing and administration—factors that determine whether a drug should be taken orally or injected, and whether it should take the form a pill, tablet, suppository, etc. Major advances in the design of drug delivery systems over the past few decades have expanded this field.
Nanotechnology applied to the design and development of drug delivery systems has created a field of research known as therapeutic nanosystems. This branch of nanomedicine is defined as the science and technology of complex systems, ranging from 1 to 1000 nm in size and typically comprising two elements, one of which is an active ingredient. These systems are specially designed to treat, prevent or diagnosis disease. They also include systems comprising a single component that have been transformed into nanoscale devices (e.g. via supercritical fluid technology).
Regenerative medicine is a fledgling area in which researchers aim to repair tissue and organs using methods based on gene therapy, cellular therapy, or tissue engineering, in which live cells are combined with biomaterials that act as scaffolds for tissue reconstruction, performing the functions of the extracellular matrix. Biomaterials for tissue engineering have evolved greatly over time. The first generation (1960-1970) simply comprised biologically inert materials; the second generation (1980-1990) consisted of bioactive or biodegradable materials; and the third generation, the current one, refers to materials capable of mimicking cellular responses at the molecular level. Owing to advances in nanotechnology, this latest generation of materials can interact with cellular components, direct cell proliferation and differentiation, and control production and organization of the extracellular matrix.
Nanomedicine is a paradigm of translational research: it draws on basic research in physics, chemistry and biology; applied research in materials science & technology, pharmacology bioelectronics, and bioengineering; and clinical medical research. Nanomedicine demands the development of an industrial sector that can transform scientific and technological advances into health technologies that can improve the quality of our lives and reduce healthcare costs. This comprises an economic arena encompassing the pharmaceutical, medical technology, and biotechnology sectors. In Catalonia the time is ripe for us to take a major stride forward in this field, considering the critical mass formed by our research centers, universities, hospitals, and pharmaceutical and medical technology industries. We must think globally and work in concert locally.
More than 200 years ago, the wise but scarcely known Catalan researcher and surgeon Antoni Cibat i Arnautó wrote: “Without knowledge of physics, chemistry and botany, no one can consider themselves to fully understand medicine and surgery”.
His philosophy is today embodied in the field of nanomedicine.