Medicine boron neutron capture therapy

The rapid development of carborane chemistry is mainly due to their practical applications. For instance, the potential utility of carborane polymers as gaskets, O-rings, and electrical connector inserts has been reported. Their functionality for solvent extraction of radionuchdes as well as the potential medicinal value of the isoelectronic and isostructural boron analogues of biologically important molecules has been the subject of many review articles. For example, a number of boron compounds have been found to possess anti-inflammatory and antiarthritic activity in animal model studies. Boron compounds have also been implicated in studies designed to probe the importance of the so-called anionic subsite of acetylcholine esterase and Ach receptors. But, by far the most interesting practical apphcations of carboranes are in areas of boron neutron capture therapy (BNCT) and supramolecular assembly. 

Boron is an essential trace element for plants and is beneficial for animals and humans. Dietary boron obviously plays a role in immune functions. Among the best-known natural boron-containing compounds are polyketide antibiotics such as boromycin, aplasmomycins, borophycin and tatrolons. Attempts are underway to incorporate boron into different biologically active molecules, particularly for medicinal application, e.g. for boron neutron capture therapy of brain tumors. Some boron-containing biomolecules may apparently act as signaling molecules that interact with cell surfaces. 

The functional derivatives prepared can be used not only for boron neutron capture therapy, but also as linkers for attachment of radioactive halogen labels to biomolecules for purposes of nuclear medicine. ... 

Elegant experiments have shown that endohedral transmutation of an element can take place within the fullerene cage while it is practically unaffected by high-energy neutron capture and )5-emission events. This was carried out on non-radioactive Gd Cg2, which transmutes into Tb Cg2 under neutron irradiation with emission of a -particle [21]. Monoisotopic Ho in macroscopic quantities (mg) of pure samples of Ho Cg2, Ho2 Cg2, or Ho3 Cg2 was also activated with a high neutron flux to produce stable Er [22]. These initial results strongly suggest that endohedral metallofullerenes may find a useful place in nuclear medicine in a way similar to boron neutron capture therapy (BNCT) [23]. 

A short description of possible nuclear applications of boron-based materials had been done by Potapov (1961) in an old overview that included the nuclear power industry (e.g., control rods of nuclear reactors) solid-state electronics (e.g., counters of neutrons and neutron energy sensors) radiation chemistry (e.g., acceleration of technological processes) etc. For these purposes, "B nuclei are useless, but °B nuclei are useful due to a large cross section of interaction with thermal neutrons, °B converts them into heavy ionizing particles. Besides, °B isotope is applicable for neutron radiation protection (Stantso 1983) and also in medicine, e.g., in boron neutron capture therapy (BNCT) for treating cancer tumors (Desson 2007). 

The book highlights the latest developments in all areas of boron chemistry. These encompass a variety of topics, including theoretical and spectroscopic studies and applications in organic synthesis and medicinal chemistry, in which boron neutron capture therapy features prominently. 

The CT scan shows a brain tumor that might be difficult or impossible to treat by conventional surgical methods. Nuclear medicine, including boron neutron capture therapy (BNCT), enables doctors to treat cancers of this type. 

The real stimulus for the development of bioorganic and medicinal chemistry of boron was provided by revival of interests in boron neutron capture therapy (BNCT) of cancers. This is connected to the progress in nuclear research reactor technology and the prospective availability of... 

The era of boron chemistry aimed at advanced jet and rocket propulsion systems ended in the early 1960s, however, the interest in the polyhedral boron hydrides as high energy density materials still persists and some salts of the c/o5o-decaborate and the c/oso-dodecaborate anions were proposed as components of components of high burning composite propellants [74]. However, the main interest in application of the polyhedral boron hydrides is connected with medicine [57,75] and traditionally centered on their use in boron neutron capture therapy for cancer [76,77]. 

Few medicines based on boron are known, in general boric acid or a boronic acid serve to esterify an a-diol or an o-diphenol. This is the case for the emetic antimony borotartrates of the ancient pharmacopoeias, for the injectable catecholamine solutions, for tolboxane, which is close to meprobamate and which was commercially available as a tranquillizer some decades ago, and also for the phenylboronic esters of chloramphenicol. Boro-mycine was the first natural product containing boron. It is a complex between boric acid and a polyhydroxylated tetradentate macrocycle. Some boronic analogues of amino acids were prepared as chymotrypsine and elastase inhibitors. The most important medical use of derivatives of boron derivatives is the treatment of some tumours by neutron capture therapy, " the problem here being to ensure a sufficient concentration of the product in the tumour being treated. 

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