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001-es BibID:	BIBFORM116532
035-os BibID:	(WoS)001070439900001 (Scopus)85169291237 (cikkazonosító)105702
Első szerző:	Benea, Ioana Cristina
Cím:	Biocatalytic synthesis of new polyesteramides from ?-caprolactam and hydroxy acids: Structural characterization, biodegradability, and suitability as drug nanocarriers / Ioana Cristina Benea, Izolda Kántor, Anamaria Todea, Alessandro Pellis, Ioan Bîtcan, Lajos Nagy, Sandor Kéki, Diana Maria Dreavā, Francisc Péter, Tivadar Feczkó
Dátum:	2023
ISSN:	1381-5148
Megjegyzések:	The synthesis of polyesters and polyamides by enzyme-catalyzed processes in vitro was developed in the last decades as a green alternative to obtain biodegradable synthetic polymers with various applications, such as nanoparticle-sized carriers for drug delivery. Polyesteramides were much less studied in this respect, although having the presumable advantage of increased mechanical and thermic resistance brought by the amide moieties. In this work, polyesteramides were synthesized for the first time employing as raw materials epsilon-caprolactam and a hydroxy acid. L-malic, 3-hydroxybutyric, 12-hydroxystearic and 16-hydroxyhexadecanoic acid, respectively, were investigated as co-monomers in solventless or organic medium, using the immobilized lipase Novozyme 435 as catalyst. The short chain hydroxy acids holding secondary hydroxyl groups yielded oligomers with average degree of polymerization no higher than 4, while in the case of the long-chain 12-hydroxystearic acid this value increased to 7. The best results were achieved by using 16-hydroxyhexadecanoic acid in 2:1 M excess at 80. C, yielding a product with 75% copolymer content and average molecular weight higher than 3000 Da. The emulsion-solvent evaporation method allowed the efficient production of nanoparticles based on this copolymer, with sizes around 230 nm, used for the encapsulation of a model bioactive compound, the anticancer drug sorafenib. Production yields of >70% and encapsulation efficiencies of around 60% are very promising for further development of this approach.
Tárgyszavak:	Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk Polyesteramide Biocatalysis Lipase Polymer nanoparticle Encapsulation
Megjelenés:	Reactive & Functional Polymers. - 191 (2023), p. 1-17. -
További szerzők:	Kántor Izolda Todea, Anamaria Pellis, Alessandro Bîtcan, Ioan Nagy Lajos (1979-) (vegyész) Kéki Sándor (1964-) (polimer kémikus) Dreava, Diana-Maria Péter, Francisc Feczkó Tivadar
Pályázati támogatás:	TKP2021-EGA-20 Egyéb
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001-es BibID:	BIBFORM115360
035-os BibID:	(WoS)001070979000001 (Scopus)85168104200 (cikkazonosító)101229
Első szerző:	Bîtcan, Ioan
Cím:	One-pot green synthesis and characterization of novel furan-based oligoesters / Ioan Bîtcan, Alessandro Pellis, Andreea Petrovici, Diana-Maria Dreavă, Iulia Păușescu, Francisc Peter, Lajos Nagy, Sándor Kéki, Lucia Gardossi, Anamaria Todea
Dátum:	2023
ISSN:	2352-5541
Megjegyzések:	The synthesis of bio-based poly(5-hydroxymethyl-2-furancarboxylate-co-ricinoleate) was investigated either from ricinoleic acid and 5-hydroxymethyl-2-furancarboxylic acid or directly from castor oil by green biocatalytic pathways. The reactions were carried out using commercially available native and immobilized hydrolases. The reactions were performed either in the absence of solvent or in different organic solvents or ionic liquids at various molar ratios and temperatures up to 80 ?C. The lipase from Pseudomonas stutzeri showed the highest catalytic efficiency at 50 ?C in t-butanol. To increase the sustainability of the process, in the next step, an original "onepot" system consisting of two consecutive reactions catalyzed by the same enzyme was developed. Ricinoleic acid, obtained by in-situ hydrolysis of castor oil, was used together with 5-hydroxymethyl-2-furancarboxylic acid as raw material for the oligoester synthesis at 100 mbar pressure in a solventless reaction system, yielding a product with average molecular weight of about 5800 gmol-1, in optimized conditions. The insertion of 5-hydroxymethyl-2-furancarboxylic acid units into the ricinoleic acid estolide backbone was demonstrated by MALDI-TOF MS and 2D NMR analysis. The thermal properties of the resulting products were evaluated by TG and DSC.
Tárgyszavak:	Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk Ricinoleic acid 5-Hydroxymethyl-2-furancarboxylic acid Enzymatic polymerization Biocatalytic one-pot synthesis
Megjelenés:	Sustainable Chemistry and Pharmacy. - 35 (2023), p. 101229-101243. -
További szerzők:	Pellis, Alessandro Petrovici Andrea Dreava, Diana-Maria Pausescu, Iulia Péter, Francisc Nagy Lajos Kéki Sándor (1964-) (polimer kémikus) Gardossi, Lucia Todea, Anamaria
Pályázati támogatás:	PN-III-P1-1.1-TE-2019-1573 Egyéb
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001-es BibID:	BIBFORM103963
035-os BibID:	(WOS)000522021900002 (Scopus)85082415468
Első szerző:	Todea, Anamaria
Cím:	Thermal behavior of oligo[(epsilon-caprolactone)-co-delta-gluconolactone] enzymatically synthesized in reaction conditions optimized by experimental design / Anamaria Todea, Diana Aparaschivei, Ioan Bîtcan, Ionuț Valentin Ledeți, Geza Bandur, Francisc Péter, Lajos Nagy, Sándor Kéki, Emese Biró
Dátum:	2020
ISSN:	1388-6150 1588-2926
Megjegyzések:	The thermal behavior of co-oligomers of epsilon-caprolactone (ECL) with gluconolactone, compared to the epsilon-caprolactone oligomer, has been assessed by thermogravimetric analysis, while differential scanning calorimetry was used to evaluate the melting comportment. As the insertion of more hydrophilic structural units can improve the properties and functionalities of the ECL oligoesters, the enzymatic in vitro oligomerization process was optimized by a 3-factorial/3-level experimental design, using the Box-Behnken method. The selected independent variables were the temperature, the enzyme amount, and the molar ratio of monomers, while the co-oligomerization degree and the mass average molecular mass (calculated from MALDI-TOF MS data) were the response variables. The results indicate that temperature has the most significant effect and is directly correlated with the formation of linear co-oligoesters. The overall effect of the other variables was also significant. The thermogravimetric analysis of the co-oligomer synthesized in the optimized conditions indicated a decrease of the thermal stability and compared to the ECL oligomer. Thermoanalytical techniques can consistently improve the utilization efficiency of polymer-based formulations in pharmaceutical and medical applications.
Tárgyszavak:	Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk Biocatalysis Enzymatic oligomerization Thermal analysis Lipaseepsilon-caprolactone delta-gluconolactone
Megjelenés:	Journal of Thermal Analysis and Calorimetry. - 141 : 3 (2020), p. 1017-1026. -
További szerzők:	Aparaschivei, Diana Bîtcan, Ioan Ledeți, Ionuț Valentin Bandur, Geza Péter, Francisc Nagy Lajos (1979-) (vegyész) Kéki Sándor (1964-) (polimer kémikus) Biro, Emese
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001-es BibID:	BIBFORM104069
035-os BibID:	(WoS)000489104300028 (Scopus)85071906261 (cikkazonosító)1402
Első szerző:	Todea, Annamaria
Cím:	Biodegradable Oligoesters of epsilon-Caprolactone and 5-Hydroxymethyl-2-Furancarboxylic Acid Synthesized by Immobilized Lipases / Anamaria Todea, Ioan Bîtcan, Diana Aparaschivei, Iulia Păuşescu, Valentin Badea, Francisc Péter, Vasile Daniel Gherman, Gerlinde Rusu, Lajos Nagy, Sándor Kéki
Dátum:	2019
ISSN:	2073-4360
Megjegyzések:	Following the latest developments, bio-based polyesters, obtained from renewable raw materials, mainly carbohydrates, can be competitive for the fossil-based equivalents in various industries. In particular, the furan containing monomers are valuable alternatives for the synthesis of various new biomaterials, applicable in food additive, pharmaceutical and medical field. The utilization of lipases as biocatalysts for the synthesis of such polymeric compounds can overcome the disadvantages of high temperatures and metal catalysts, used by the chemical route. In this work, the enzymatic synthesis of new copolymers of ?-caprolactone and 5-hydroxymethyl-2-furancarboxylic acid has been investigated, using commercially available immobilized lipases from Candida antarctica B. The reactions were carried out in solvent-less systems, at temperatures up to 80 C. The structural analysis by MALDI TOF-MS, NMR, and FT-IR spectroscopy confirmed the formation of cyclic and linear oligoesters, with maximal polymerization degree of 24 and narrow molecular weight distribution (dispersity about 1.1). The operational stability of the biocatalyst was explored during several reuses, while thermal analysis (TG and DSC) indicated a lower thermal stability and higher melting point of the new products, compared to the poly(epsilon-caprolactone) homopolymer. The presence of the heterocyclic structure in the polymeric chain has promoted both the lipase-catalyzed degradation and the microbial degradation. Although, poly(epsilon-caprolactone) is a valuable biocompatible polymer with important therapeutic applications, some drawbacks such as low hydrophilicity, low melting point, and relatively slow biodegradability impeded its extensive utilization. In this regard the newly synthesized furan-based oligoesters could represent a "green" improvement route.
Tárgyszavak:	Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk copolymerization renewable oligoester lipase furan-based epsilon-caprolactone
Megjelenés:	Polymers. - 11 : 9 (2019), p. 1-17. -
További szerzők:	Bîtcan, Ioan Aparaschivei, Diana Pausescu, Iulia Badea, Valentin Francisc Péter Gherman, Vasile Daniel Rusu, Gerlinde Nagy Lajos (1979-) (vegyész) Kéki Sándor (1964-) (polimer kémikus)
Pályázati támogatás:	GINOP-2.3.3-15-2016-00021 GINOP
Internet cím:	DOI Intézményi repozitóriumban (DEA) tárolt változat
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