Nanotechnology in Therapeutics: hydrogels and beyond

Nanotechnology in Therapeutics: Current Technology and Applications, Edited by Nicholas A. Peppas, J. Zach Hilt and J. Brock Thomas (Horizon Bioscience, 2007) contains seventeen chapters written by leading specialists in the field of polymeric materials for drug delivery and holds wealth of background as well as state of the art material divided into four sections: "Intelligent Therapeutics and Responsive Delivery Systems for Improved Absorption and Delivery", "Therapeutic Micro- and Nanodevices", "Nanostructured Therapeutic Materials" and "Nanoparticulate Systems in Intelligent Therapy". This newly published volume provides a stimulating read and a good point of reference to researchers wishing to explore the interdisciplinary fusion of nnanotechnology and medical therapeutics. The following gives brief summary and critically reviews the book.     

Structural-metabolic changes in the ventricular myocardium in massive experimental pulmonary embolism]

A comparative study of hemodynamic and structural-metabolic changes in myocardium of right (RV) and left (LV) ventricles by compensative massive pulmonary embolism (MPE) and decompensated MPE was made in 29 mongrel dogs. By decompensated MPE the histoenzymological and ultrastructural methods reveal changes in RV which are not adequate to its high hemodynamic load: the catabolic enzymes activity decreases, the numeral density of mitochondrial profiles decreases too, the fraction of damaged mitochondria increases. By decompensated MPE the myocardial metabolism shifts from catabolic to biosynthetic processes, the activity of NADP.H-D and G-6-PDG increase in both ventricles.     

Singlet oxygen scavenging activity of tocopherol and plastochromanol in Arabidopsis thaliana: relevance to photooxidative stress

In the present study, singlet oxygen (¹O₂) scavenging activity of tocopherol and plastochromanol was examined in tocopherol cyclase‐deficient mutant (vte1) of Arabidopsis thaliana lacking both tocopherol and plastochromanol. It is demonstrated here that suppression of tocopherol and plastochromanol synthesis in chloroplasts isolated from vte1 Arabidopsis plants enhanced ¹O₂ formation under high light illumination as monitored by electron paramagnetic resonance spin‐trapping spectroscopy. The exposure of vte1 Arabidopsis plants to high light resulted in the formation of secondary lipid peroxidation product malondialdehyde as determined by high‐pressure liquid chromatography. Furthermore, it is shown here that the imaging of ultra‐weak photon emission known to reflect oxidation of lipids was unambiguously higher in vte1 Arabidopsis plants. Our results indicate that tocopherol and plastochromanol act as efficient ¹O₂ scavengers and protect effectively lipids against photooxidative damage in Arabidopsis plants.     

Effect of nematoda Aphanitylenchus sp. on the reproductive capacity of fleas Ceratophyllus consimilis

The paper presents results of experimental studies of the effect of Allantonematidae on the reproduction of fleas. It has been established that the pairing of non-infected females with males infected with nematodes reduces the fecundity rate while the pairing of non-infected males with females infected with nematodes causes a complete stopping of reproduction of laboratory population. The conclusion was drawn on the role of allantonematides in the regulation of abundance of fleas of rodents in nature.     

Interconnection of carbohydrate and lipid metabolism in various modes of muscle activity

The activity of hexokinase and lipase has been determined in skeletal muscles of different metabolic types and adipose tissue of untrained albino rats during two variations of predominant aerobic physical exercise: long-term swimming and long-term swimming including short-term loads (20 s) of maximal intensity (acceleration). Muscle and liver glycogen depletion, serum lactate, glucose and free fatty acids concentrations are also investigated. It is shown that long-term swimming (first variation) has promoted a decrease of both enzymatic activities in muscle fibres and an increase in lipolytic activity of the adipose tissue. During the physical exercise with the acceleration an increase in hexokinase activity occurs in response to 20 min swimming, with its maximal decrease in response to 40 min of exercise. Activity of lipase in slow-twitch oxidative fibres of soleus and in the adipose tissue increases from 20 min to the end of the exercise. Depletion of glycogen in the muscles and liver is determined in fast-twitch oxidative-glycolytic fibres and in the liver in two types of exercises, being more significant in muscles after exercise with accelerations. Concentrations of serum lactate, glucose and free fatty acids remain unchanged after both variations of swimming. So, it may be concluded that acute adaptation to the predominant aerobic physical exercise with activity under short-term loads of maximal intensity has induced a rise of the capacity of oxidative muscles to utilise endogenous and exogenous carbohydrate and lipid reserves.     

Cellular protrusions of luminescent bacteria and relation of their appearance to cultivation conditions]

The luminescent cells of Photobacterium were studied by electron microscopy in order to establish what caused their sticking together and growth on the glass walls of the vessel during continuous cultivation. Electron microscopy revealed protrusions, of various shape and size, on the cells. The phenomenology of various protrusions, including fimbria, is described, and the effect of cultivation conditions (continuous culture, periodic culture) and growth phases on their emergence was elucidated. The sticking of the cells together and their growth on the glass walls were less expressed at pH between 7.5 and 7.9, when the amount of the cells with the fimbria was the least and they were formed during the later phase of growth.     

The functional-morphological state of the myocardium in experimental massive embolism of the pulmonary artery]

A comparative study of hemodynamic and structural-metabolic changes in the myocardium of the right (RV) and left ventricles (LV) in acute massive pulmonary artery embolism was made in 19 mongrel dogs. In the control group the activity of SDH, MDH, GDH, NADH-DH in LV were higher than in RV. The numeral density and relative area of mitochondrial profile surface in LV was higher that in RV. A significant increase in afterload on RV causes intensification of cell respiration, a rise in numeral density and relative area of mitochondrial profile surface. Weakening of LV work leads to contrary structural-metabolic changes. Thus, contrary changes in hemodynamic loads on RV and LV in acute compensative massive pulmonary artery embolism correlated with contrary changes in their cell metabolism.