This study describes the preparation of nanoparticles derived from bovine serum albumin (BSA) in comparison with the formation of nanoparticles composed of human serum albumin (HSA), when the same preparation procedure was used in both cases. To obtain protein nanoparticles, the method of desolvation with ethanol was employed, followed by the stabilization with urea and cysteine. It was shown that, upon transition from HSA to BSA, the particles with smaller sizes and with a narrower polydispersity were formed. The possibility of the immobilization of the antitumor drug hydroxyurea in such protein nanoparticles by adsorption and inclusion methods has been shown. The drug release profile from the polymer matrix was established.

Human serum albumin nanoparticles (HSA-NPs) have been widely used as drug delivery systems. In most cases, HSA-NPs are formed by the method of desolvation in the presence of glutaraldehyde as a crosslinking agent. In the present study, we showed the possibility of crosslinking human serum albumin (HSA) molecules with natural agents, urea, and cysteine at the nanoparticle level under mild conditions (at room temperature of 20–25 °C). Optimal concentrations of the interacting components (HSA, urea, and cysteine) were found to produce nanoparticles with optimal physico-chemical parameters (particle size, polydispersity, zeta potential, yield, etc.) for application as drug carriers. We used hydroxyurea (HU), a simple organic compound currently used as a cancer chemotherapeutic agent. The results indicated sizes of 196 ± 5 nm and 288 ± 10 nm with a surface charge of −22 ± 3.4 mV and −17.4 ± 0.5 mV for HSA-NPs (20 mg/mL of HSA, 0.01 mg/mL of cysteine, and 10 mg/mL of urea) and HSA–HU-NPs (2 mg/mL of HU), respectively. The yield of the HSA–HU-NPs was ~93% with an encapsulation efficiency of ~77%. Thus, the particles created (immobilized with HU) were stable over time and able to prolong the effect of the drug.

В работе исследовано влияние различных УФ-стабилизаторов на физико-механические свойства полипропиленовых нитей, полотна и клапанно-коробчатых мешков, полученных методом экструзии с последующей ориентацией. Рассмотрены механизмы фотоокислительной деградации полимеров и принципы действия светостабилизаторов на основе стерически затруднённых аминов (HALS) и УФ-абсорберов. В качестве объектов исследования использованы три промышленных светостабилизатора, введённые в полипропиленовую композицию. Проведены испытания образцов до и после ускоренного УФ-старения (168 и 336 часов) с оценкой прочности, удлинения, линейной плотности и остаточной усадки. Установлено, что эффективность стабилизаторов существенно различается: наилучшую стойкость к фотодеструкции показал стабилизатор UV 5010 PE, тогда как POL PE 920052-UV обеспечил наибольшую технологическую стабильность переработки. Исследование влияния концентрации POL PE 920052-UV в диапазоне 1–2 % показало, что увеличение его содержания сопровождалось ростом линейной плотности и массы изделий, при этом относительное удлинение нити снижалось, а прочность сварного дна мешков уменьшалась. В исследованном диапазоне концентраций наилучшее сочетание показателей получено при содержании стабилизатора POL PE 920052-UV 1 %. Полученные результаты могут быть использованы при разработке и промышленном производстве полипропиленовой упаковочной продукции.

This article presents a critical review of chemical and technological approaches to the production of composites based on recycled polyolefins using thermoplastic processing. The aim of the review is to identify the relationships between feedstock condition, changes during processing, interactions between components, and material propertie. The main focus is on recycled polyethylene and polypropylene, including mixed and multi-component waste. The influence of the origin, contaminants and thermomechanical history of the raw materials on processability is analysed. Chain scission, branching and cross-linking are examined, together with their effects on molecular-weight characteristics, crystallinity and rheological behaviour. Methods for stabilising polymers and modifying composites using fillers and compatibilisers are summarised. The roles of extrusion, co-extrusion, injection moulding, calendering and compression moulding are analysed. It is shown that the content of recycled polymer and the melt flow index, taken separately, are insufficient for predicting properties. Environmental, economic and regulatory aspects are considered. The need for an integrated ‘chemical changes – structure – technology – properties’ approach is justified; this approach enables the targeted formation of the structure and regulation of the performance characteristics of composites through the selection of composition, modifiers and processing conditions.