In order to provide novel polymeric biomaterials for chemotherapeutic purposes, in this paper we described the synthesis and the characterization of the physicochemical properties of a betulin-based polyanhydride exhibiting anti-cancer effects. The polyanhydride was obtained by a melt polycondensation of a disuccinate betulin (3,28-di-O-succinyl betulin), and was thoroughly characterized through 1H NMR and 13C NMR spectroscopies, correlation spectroscopy, heteronuclear single quantum correlation, size exclusion chromatography, differential scanning calorimetry and FT-IR spectroscopy. It was confirmed, that the obtained polyanhydride undergoes hydrolytic degradation, releasing disuccinate betulin as a degradation product. Polyanhydride of a disuccinate betulin was tested for cytostatic activity against a wide range of cancer cell lines (HeLa, MCF-7, A-549, U-87MG, KB and HepG2), proving its efficiency in inhibiting the growth of selected cancer cells. To realize the concept of an easily administrated drug release system, polyanhydride was fabricated in a form of micro- (1–30 μm) and nanospheres (∼400 nm) by using an emulsion solvent evaporation method. The micro- and nanospheres were characterized by SEM.
Emulsion explosives (EE) have been commercially available in various forms for over 50 years. Over this period, the popularity and production technology of this class of energetic materials have been developing constantly. Despite this rapid rise to prominence and, in some applications, prevalence over traditional energetic materials, remarkably little information is available on the physicochemical and energetic properties of these materials and factors affecting those properties. This work is dedicated to presenting the fundamental information relevant to the features, properties and applications of EEs, while highlighting the most significant recent progress pertaining to those materials. Particular emphasis has been given to providing information about the types, composition, modifications and detonation parameters of EEs, as well as to highlighting the less obvious, emerging applications of EEs.
16 February 2000 in Reactive and Functional Polymers