Biosensors. Switching channels makes sense

Natural and artificial ion channels for biosensing platforms

The single-molecule selectivity and specificity of the binding process together with the expected intrinsic gain factor obtained when utilizing flow through a channel have attracted the attention of analytical chemists for two decades. Sensitive and selective ion channel biosensors for high-throughput screening are having an increasing impact on modern medical care, drug screening, environmental monitoring, food safety, and biowarefare control. Even virus antigens can be detected by ion channel biosensors. The study of ion channels and other transmembrane proteins is expected to lead to the development of new medications and therapies for a wide range of illnesses. From the first attempts to use membrane proteins as the receptive part of a sensor, ion channels have been engineered as chemical sensors. Several other types of peptidic or nonpeptidic channels have been investigated. Various gating mechanisms have been implemented in their pores. Three technical problems had to be solved to achieve practical biosensors based on ion channels: the fabrication of stable lipid bilayer membranes, the incorporation of a receptor into such a structure, and the marriage of the modified membrane to a transducer. The current status of these three areas of research, together with typical applications of ion-channel biosensors, are discussed in this review.

The genesis of neurosurgery and the evolution of the neurosurgical operative environment: part II--concepts for future development, 2003 and beyond

The future development of the neurosurgical operative environment is driven principally by concurrent development in science and technology. In the new millennium, these developments are taking on a Jules Verne quality, with the ability to construct and manipulate the human organism and its surroundings at the level of atoms and molecules seemingly at hand. Thus, an examination of currents in technology advancement from the neurosurgical perspective can provide insight into the evolution of the neurosurgical operative environment. In the future, the optimal design solution for the operative environment requirements of specialized neurosurgery may take the form of composites of venues that are currently mutually distinct. Advances in microfabrication technology and laser optical manipulators are expanding the scope and role of robotics, with novel opportunities for bionic integration. Assimilation of biosensor technology into the operative environment promises to provide neurosurgeons of the future with a vastly expanded set of physiological data, which will require concurrent simplification and optimization of analysis and presentation schemes to facilitate practical usefulness. Nanotechnology derivatives are shattering the maximum limits of resolution and magnification allowed by conventional microscopes. Furthermore, quantum computing and molecular electronics promise to greatly enhance computational power, allowing the emerging reality of simulation and virtual neurosurgery for rehearsal and training purposes. Progressive minimalism is evident throughout, leading ultimately to a paradigm shift as the nanoscale is approached. At the interface between the old and new technological paradigms, issues related to integration may dictate the ultimate emergence of the products of the new paradigm. Once initiated, however, history suggests that the process of change will proceed rapidly and dramatically, with the ultimate neurosurgical operative environment of the future being far more complex in functional capacity but strikingly simple in apparent form.

New technologies in medicine: biotechnology and nanotechnology

In February 1997, researchers created Dolly, a lamb cloned from the DNA of an adult sheep. This was supposed to be impossible (or at least generations away), but suddenly it was here--a clone of a higher mammal. Whatever Dolly's ultimate significance, she conclusively demonstrated the growing power of biotechnology. Many have come to the conclusion that advances in biotechnology will fundamentally transform medicine during the coming decade. Society is in the midst of a technical revolution that will have the same relevance as the development of the printing press, the internal combustion engine, and the microprocessor. Computers have become the key tools in the accelerating progress that is occurring in the field of biotechnology. At the same time, genetic, evolutionary, and other biologic processes are providing new models for the development of computer hardware and software. Today represents the early stages of what has been called the "bionic convergence": the convergence of the biologic revolution with the information revolution, the joining of biology with electronics. Virtually everything that is important to health care practitioners and patients--diagnostic techniques, means of understanding disease causes, methods of treatment, approaches to prevention, health care facility design, medical education, and legal and ethical issues--will be changed by the revolutions currently underway in the fields of biotechnology and genetic medicine. The following monograph includes several forecasts about a range of possible opportunities that may have enormous effects on health care during the next century. These forecasts address the potential impacts of biotechnology on disease detection and diagnosis, treatment, prevention, nanotechnology, and other areas of medical significance. Every area of beneficiary care will be affected as the changes implied by these forecasts begin to develop. Beneficiary care will continue to see the emergence of a "forecast, prevent, and manage" paradigm. The emphasis will be on disease prevention, health promotion, and the creation of healthy communities. New diagnostic and treatment opportunities will be available as a consequence of breakthroughs in genetic medicine. The health care system will view health as a whole, as a person's overall sense of well-being--an entity that encompasses much more than the absence of symptoms.