| 1. |
- Stasiuk, A. V., et al.
(författare)
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Influence of structure and nature of pseudo-poly(amino acid)s on size and morphology of their particle in self-stabilized aqueous dispersions
- 2023
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Ingår i: Applied Nanoscience. - Germany : Springer. - 2190-5509 .- 2190-5517. ; 13:7, s. 5011-5019
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Tidskriftsartikel (refereegranskat)abstract
- Polyester pseudo-poly(amino acid)s due to their biodegradability and biocompatibility are promising materials for the development of dispersed systems for drug delivery. It is essential for drug delivery systems to reach the target site within a certain period before they are eliminated or degraded. Biodegradable materials should meet the following criteria: (1) possess surface-active properties; (2) be non-toxic; (3) form self-stabilized dispersions with the size of the dispersed phase in the range of 10–100 nm. Polyesters based on N-derivatives of dicarboxylic α-amino acids and hydrophilic PEG diols modified with phosphate group meet the requirements to the dispersed drug delivery systems. Obtained polyesters have a complex architecture consisting of hydrophilic fragments, which stabilize the system, and lipophilic fragments, which solubilize biologically active substances. The phosphate group introduced into the hydrophilic chain of polyoxyethylene glycol provides chemisorption of a number of biologically active substances due to the formation of ionic bonds between them. Synthesized polyesters form self-stabilized dispersed systems, which do not require additional stabilizing agents when used for medical applications.
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| 2. |
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| 3. |
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| 4. |
- Dron, Iryna, et al.
(författare)
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Investigation of Hydrogel Sheets Based on Highly Esterified Pectin
- 2022
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Ingår i: Chemistry & Chemical Technology. - Ukraine : Lviv Polytechnic National University. - 1996-4196 .- 1996-4196. ; 16:2, s. 220-226
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Tidskriftsartikel (refereegranskat)abstract
- The report describes the features of physical and mechanical properties and absorption capacity of hydrogels based on highly esterified pectin. Experimental data showed the correlation between these values. Also, an attempt is made to explain the obtained dependencies via the hydrogel morphology and the mechanism of its formation.
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| 5. |
- Kozak, Mariya, et al.
(författare)
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Polyphosphate Ester-Type Transporters Improve Antimicrobial Properties of Oxytetracycline
- 2023
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Ingår i: MDPI. - : MDPI AG. ; 12:3, s. 1-12
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Prolonged use of antibiotics can cause toxicity in human and animal cells and lead to the development of antibiotic resistance. The development of drug delivery systems for enhanced antibacterial properties of antibiotics could reduce toxic effects and minimize the development of resistance. The aim of this study was to evaluate the effectiveness of oxytetracycline in complexes with new polyphosphate ester-type transporters and to investigate the antimicrobial effect of these complexes on Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus growth in vitro. Two polyphosphate ester-type transporters with different molecular weights were synthesized, and oxytetracycline was attached through the phosphorus groups. To determine the sensitivities of microorganisms, oxytetracycline hydrochloride and oxytetracycline complexes with polyphosphate ester-type transporters (P4 and P6) were added to liquid and solid media with E. coli, P. aeruginosa, and S. aureus in different doses. Oxytetracycline in complex with polyphosphate ester-type transporters at low doses (2.3 to 3.8 μg/disk or μg/mL) in both solid and liquid media inhibits the growth of S. aureus more effectively than oxytetracycline alone. The maximum influence on E. coli growth on solid media is observed at a dose of 8 μg/disk of oxytetracycline in combination with both P4 and P6 polyphosphate ester-type transporters. P. aeruginosa growth under the influence of oxytetracycline in combination with polyphosphate-ester type transporters in a liquid medium depends on the dose of antibiotic and the day of cultivation.
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| 6. |
- Nahorniak, Mykhailo, et al.
(författare)
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Synthesis and study on the properties of polysaccharides modified via the Steglich reaction
- 2023
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Ingår i: Applied Nanoscience. - 2190-5509 .- 2190-5517.
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Tidskriftsartikel (refereegranskat)abstract
- Modified polysaccharides are widely used as polymers for medical and biomedical purposes. Among them, the products with a crosslinked macromolecular structure occupy an important place. For instance, using N-derivatives of glutamic acid as a crosslinking agent makes it is possible to obtain non-toxic biodegradable polymer materials. In the current work, the results of study on the polysaccharides modification with N-derivatives of glutamic acid via the Steglich esterification reaction are provided. The factors influencing the efficiency of developed synthetic approach were considered, and the structure and composition of the obtained reaction products were investigated. The reaction was shown to proceed successfully by exploiting both carboxyl groups of N-derivatives of glutamic acid, resulting in the cross-linking of polysaccharide molecules under mild conditions. The study of the properties of the obtained products and the NMR study of their structure and composition showed that two fundamentally different polymers were formed—macromolecules with branched and crosslinked structures. The latter, under certain reaction conditions, formed microhydrogels while dispersing in water. Meanwhile, the branched macromolecules were capable of forming self-stabilized aqueous dispersions. Thus, the article presents the research results on the creation of novel polymers for potential medical applications.
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| 7. |
- Tkachenko, Oleg, et al.
(författare)
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Kraft Lignin-Derived Microporous Nitrogen-Doped Carbon Adsorbent for Air and Water Purification
- 2024
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Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 16:3, s. 3427-3441
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Tidskriftsartikel (refereegranskat)abstract
- The study presents a streamlined one-step process for producing highly porous, metal-free, N-doped activated carbon (N-AC) for CO2 capture and herbicide removal from simulated industrially polluted and real environmental systems. N-AC was prepared from kraft lignin─a carbon-rich and abundant byproduct of the pulp industry, using nitric acid as the activator and urea as the N-dopant. The reported carbonization process under a nitrogen atmosphere renders a product with a high yield of 30% even at high temperatures up to 800 °C. N-AC exhibited a substantial high N content (4–5%), the presence of aliphatic and phenolic OH groups, and a notable absence of carboxylic groups, as confirmed by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and Boehm’s titration. Porosity analysis indicated that micropores constituted the majority of the pore structure, with 86% of pores having diameters less than 0.6 nm. According to BET adsorption analysis, the developed porous structure of N-AC boasted a substantial specific surface area of 1000 m2 g–1. N-AC proved to be a promising adsorbent for air and water purification. Specifically, N-AC exhibited a strong affinity for CO2, with an adsorption capacity of 1.4 mmol g–1 at 0.15 bar and 20 °C, and it demonstrated the highest selectivity over N2 from the simulated flue gas system (27.3 mmol g–1 for 15:85 v/v CO2/N2 at 20 °C) among all previously reported nitrogen-doped AC materials from kraft lignin. Moreover, N-AC displayed excellent reusability and efficient CO2 release, maintaining an adsorption capacity of 3.1 mmol g–1 (at 1 bar and 25 °C) over 10 consecutive adsorption–desorption cycles, confirming N-AC as a useful material for CO2 storage and utilization. The unique cationic nature of N-AC enhanced the adsorption of herbicides in neutral and weakly basic environments, which is relevant for real waters. It exhibited an impressive adsorption capacity for the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) at 96 ± 6 mg g–1 under pH 6 and 25 °C according to the Langmuir–Freundlich model. Notably, N-AC preserves its high adsorption capacity toward 2,4-D from simulated groundwater and runoff from tomato greenhouse, while performance in real samples from Fyris river in Uppsala, Sweden, causes a decrease of only 4–5%. Owing to the one-step process, high yield, annual abundance of kraft lignin, and use of environmentally friendly activating agents, N-AC has substantial potential for large-scale industrial applications.
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