Applications of viral nanoparticles in medicine

Several nanoparticle platforms are currently being developed for applications in medicine, including both synthetic materials and naturally occurring bionanomaterials such as viral nanoparticles (VNPs) and their genome-free counterparts, virus-like particles (VLPs). A broad range of genetic and chemical engineering methods have been established that allow VNP/VLP formulations to carry large payloads of imaging reagents or drugs. Furthermore, targeted VNPs and VLPs can be generated by including peptide ligands on the particle surface. In this article, we highlight state-of-the-art virus engineering principles and discuss recent advances that bring potential biomedical applications a step closer. Viral nanotechnology has now come of age and it will not be long before these formulations assume a prominent role in the clinic.     

Applications of Discrete Molecular Dynamics in biology and medicine

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Silicon nanoparticles: applications in cell biology and medicine

In this review, we describe the synthesis, physical properties, surface functionalization, and biological applications of silicon nanoparticles (also known as quantum dots). We compare them against current technologies, such as fluorescent organic dyes and heavy metal chalcogenide-based quantum dots. In particular, we examine the many different methods that can be used to both create and modify these nanoparticles and the advantages they may have over current technologies that have stimulated research into designing silicon nanoparticles for in vitro and in vivo applications.     

Technetium in biology and medicine

Although twenty-eigth radionuclides of technetium have been prepared, only technetium-99m, technetium-99 and technetium-95m have so far become important.Technetium-99, available in large amounts, is used in the study of the physical and chemical properties of the element, and offers the possibility of many industrial applications where its radioactivity does not create serious problems. With the increase in the use of nuclear power, however, more and more technetium-99 is being produced which is entering into the environment. This has resulted in increased interest in the biogeochemical behaviour of this radionuclide during recent years.The ideal physical properties, half-life of 6 hours and monochromatic gamma emission of 140 kev, and the versatile chemistry of technetium-99m have recently made it the radiotracer of choice for the external noninvasive imaging of almost all internal organs of the body. In the preparation of technetium- 99m radiopharmaceuticals and in the interpretation of their biological behaviour, the chemistry of technetium-99 has so far served as a guide. Similarly assumptions have been made that technetium-95m and technetium-99 have identical biogeochemical behaviour. We have shown that even the radioisomers, technetium-99m and technetium-99, have different chemical properties. These results suggest that in the study of the biological and environmental behaviour of technetium, a rigorous knowledge of the chemistry of each radionuclide is needed.     

Mitochondria in biology and medicine

Ever since the first diagnosis of a mitochondrial disease in 1959 (Ernster et al., 1959), the interest for mitochondrial cytopathies has continued to increase. Originally it was believed that the condition was very rare and primarily effected high-energy requiring tissues resulting in a select few pathologies (Luft, 1994). Since 1959, the understanding of mitochondrial cytopathies has evolved immensely and mitochondrial cytopathies are now known to be the largest group of metabolic diseases and to be resulting in a wide variety of pathologies. "Mitochondria in Biology and Medicine" was the title of the first annual conference of Society of Mitochondrial Research and Medicine - India. The conference was organized by A. S. Sreedhar, Keshav Singh and Kumarasamy Thangaraj, and was held at The Centre for Cellular and Molecular Biology (CCMB) Hyderabad, India, during 9-10 December 2011. The conference featured talks from internationally renowned scientists within the field of mitochondrial research and offered both students and fellow researchers a comprehensive update to the newest research within the field. This paper summarizes key outcomes of the presentations.     

Microarrays in biology and medicine

The remarkable speed with which biotechnology has become critical to the practice of life sciences owes much to a series of technological revolutions. Microarray is the latest invention in this ongoing technological revolution. This technology holds the promise to revolutionize the future of biology and medicine unlike any other technology that preceded it. Development of microarray technology has significantly changed the way questions about diseases and/or biological phenomena are addressed. This is because microarrays facilitate monitoring the expression of thousands of genes or proteins in a single experiment. This enormous power of microarrays has enabled scientists to monitor thousands of genes and their products in a given living organism in one experiment, and to understand how these genes function in an orchestrated manner. Obtaining such a global view of life at the molecular level was impossible using conventional molecular biological techniques. However, despite all the progress made in developing this technology, microarray is yet to reach a point where all data are obtained, analyzed, and shared in a standardized fashion. The present article is a brief overview of microarray technologies and their applications with an emphasis on DNA microarray.     

Regenerative biology and medicine

The replacement of damaged tissues and organs with tissue and organ transplants or bionic implants has serious drawbacks. There is now emerging a new approach to tissue and organ replacement, regenerative biology and medicine. Regenerative biology seeks to understand the cellular and molecular differences between regenerating and non-regenerating tissues. Regenerative medicine seeks to apply this understanding to restore tissue structure and function in damaged, non-regenerating tissues. Regeneration is accomplished by three mechanisms, each of which uses or produces a different kind of regeneration-competent cell. Compensatory hyperplasia is regeneration by the proliferation of cells which maintain all or most of their differentiated functions (e.g., liver). The urodele amphibians regenerate a variety of tissues by the dedifferentiation of mature cells to produce progenitor cells capable of division. Many tissues contain reserve stem or progenitor cells that are activated by injury to restore the tissue while simultaneously renewing themselves. All regeneration-competent cells have two features in common. First, they are not terminally differentiated and can re-enter the cell cycle in response to signals in the injury environment. Second, their activation is invariably accompanied by the dissolution of the extracellular matrix (ECM) surrounding the cells, suggesting that the ECM is an important regulator of their state of differentiation. Regenerative medicine uses three approaches. First is the transplantation of cells into the damaged area. Second is the construction of bioartificial tissues by seeding cells into a biodegradable scaffold where they produce a normal matrix. Third is the use of a biomaterial scaffold or drug delivery system to stimulate regeneration in vivo from regeneration-competent cells. There is substantial evidence that non-regenerating mammalian tissues harbor regeneration-competent cells that are forced into a pathway of scar tissue formation. Regeneration can be induced if the factors leading to scar formation are inhibited and the appropriate signaling environment is supplied. An overview of regenerative mechanisms, approaches of regenerative medicine, research directions, and research issues will be given.     

Magnetism in biology and medicine]

In the paper is made an excursion into the history of foundation of electrobiology as a science with its two main trends--magnitobiology and biomagnetism. The main experimental results are given, which became a basis of a widespread application of the electromagnetic fields of different biotropic parameters in the therapy of many diseases. The possibilities are revealed of the application of the methods of recording the magnetic fields of the human brain and heart for the diagnostics of human functional and pathological states.     

γ-Secretase in biology and medicine

γ-Secretase is a membrane-embedded proteolytic complex composed of presenilin and three other subunits. The γ-secretase complex generates the amyloid β-peptide of Alzheimer's disease but also plays important roles in normal physiology, especially in signaling from the Notch receptor. How this hydrolytic enzyme works in a hydrophobic environment is largely unanswered, but mutagenesis and chemical probes have offered insight. γ-Secretase is an important therapeutic target, although mechanism-based toxicity presents a serious obstacle. Agents that lower amyloid β-peptide production while leaving important normal functions of γ-secretase intact are promising therapeutic leads. Inhibition of Notch signaling by γ-secretase inhibitors, which is undesirable for the prevention or treatment of Alzheimer's disease, may be beneficial for the treatment of a variety of cancers.     

Optical tweezers in biology and medicine

Optical trapping techniques provide unique means to manipulate biological particles such as virus, living cells and subcellular organelles. Another area of interest is the measurement of mechanical (elastic) properties of cell membranes, long strands of single DNA molecule, and filamentous proteins. One of the most attractive applications is the study of single motor molecules. With optical tweezers traps, one can measure the forces generated by single motor molecules such as kinesin and myosin, in the piconewton range and, for the first time, resolve their detailed stepping motion.     

Prion phenomenon in medicine and biology

The data obtained suggest that the fatal changes in brain tissue associated with the prion diseases, are initiated by a conformational rearrangement of constitutively expressed cellular protein PrP. Possible mechanisms of such a conversion of this protein are discussed. Existence of the proteins with the prion properties in low eukaryotes may determine the unusual mechanisms of the "protein" inheritance. A new experimental model for studying the proteins with the prion properties in the yeast Saccharomyces cerevisiae, is described.     

Carbon monoxide in biology and medicine

Carbon monoxide (CO), a product of organic oxidation processes, arises in vivo during cellular metabolism, most notably heme degradation. CO binds to the heme iron of most hemoproteins. Tissue hypoxia following hemoglobin saturation represents a principle cause of CO-induced mortality in higher organisms, though cellular targets cannot be excluded. Despite extreme toxicity at high concentrations, low concentrations of CO can confer cytoprotection during ischemia/reperfusion or inflammation-induced tissue injury. Likewise, heme oxygenase, an enzyme that produces CO, biliverdin and iron, as well as a secondary increase in ferritin synthesis, from the oxidation of heme, can confer protection in vivo and in vitro. CO has been shown to affect several intracellular signaling pathways, including guanylate cyclase, which generates guanosine 3':5' cyclic monophosphate and the mitogen-activated protein kinases (MAPK). Such pathways mediate, in part, the known vasoregulatory, anti-inflammatory, anti-apoptotic and anti-proliferative effects of this gas. Exogenous CO delivered at low concentrations is showing therapeutic potential as an anti-inflammatory agent and as such can modulate numerous pathophysiological states. This review will delve into the biological significance and medical applications of this gas molecule.     

Applications of microfluidics in chemical biology

This review discusses the application of microfluidics in chemical biology. It aims to introduce the reader to microfluidics, describe characteristics of microfluidic systems that are useful in studying chemical biology, and summarize recent progress at the interface of these two fields. The review concludes with an assessment of future directions and opportunities of microfluidics in chemical biology.     

Extracellular superoxide dismutase in biology and medicine

Accumulated evidence has shown that reactive oxygen species (ROS) are important mediators of cell signaling events such as inflammatory reactions (superoxide) and the maintenance of vascular tone (nitric oxide). However, overproduction of ROS such as superoxide has been associated with the pathogenesis of a variety of diseases including cardiovascular diseases, neurological disorders, and pulmonary diseases. Antioxidant enzymes are, in part, responsible for maintaining low levels of these oxygen metabolites in tissues and may play key roles in controlling or preventing these conditions. One key antioxidant enzyme implicated in the regulation of ROS-mediated tissue damage is extracellular superoxide dismutase (EC-SOD). EC-SOD is found in the extracellular matrix of tissues and is ideally situated to prevent cell and tissue damage initiated by extracellularly produced ROS. In addition, EC-SOD is likely to play an important role in mediating nitric oxide-induced signaling events, since the reaction of superoxide and nitric oxide can interfere with nitric oxide signaling. This review will discuss the regulation of EC-SOD and its role in a variety of oxidant-mediated diseases.