Zirconium (IV) Acetylacetonate: Ring-Opening Initiator Mediating One-Step Synthesis of Biodegradable Polyacids

Dobrzyński, P.; Pastusiak, Małgorzata; Jaworska, Joanna; Kaczmarczyk, Bożena; Kwiecień, Michał; Kawalec, Michał

doi:10.1155/2019/3761430

Cited by 13 publications

(22 citation statements)

References 33 publications

(48 reference statements)

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“…It is suspected that at high temperatures, the propagation rate is much higher than the initiation rate of the polymerization process, and the prolonged reaction time exacerbates this effect. Elevated Đ values were noted for another zirconium-based catalyst when the reaction was carried out under similar conditions [ 40 ]. For the reaction carried out in optimized conditions (140 °C, 24 h), the Đ values were acceptable.…”

Section: Resultsmentioning

confidence: 99%

Hydrogels Based on Poly(Ether-Ester)s as Highly Controlled 5-Fluorouracil Delivery Systems—Synthesis and Characterization

et al. 2020

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A novel and promising hydrogel drug delivery system (DDS) capable of releasing 5‑fluorouracil (5-FU) in a prolonged and controlled manner was obtained using ε‑caprolactone‑poly(ethylene glycol) (CL-PEG) or rac‑lactide-poly(ethylene glycol) (rac‑LA-PEG) copolymers. Copolymers were synthesized via the ring-opening polymerization (ROP) process of cyclic monomers, ε‑caprolactone (CL) or rac-lactide (rac-LA), in the presence of zirconium(IV) octoate (Zr(Oct)4) and poly(ethylene glycol) 200 (PEG 200) as catalyst and initiator, respectively. Obtained triblock copolymers were characterized by nuclear magnetic resonance (NMR) and gel permeation chromatography (GPC) techniques; the structure and tacticity of the macromolecules were determined. The relationship between the copolymer structure and the reaction conditions was evaluated. The optimal conditions were specified as 140 °C and 24 h. In the next step, CL-PEG and rac-LA-PEG copolymers were chemically crosslinked using hexamethylene diisocyanate (HDI). Selected hydrogels were subjected to in vitro antitumor drug release studies, and the release data were analyzed using zero-order, first-order, and Korsmeyer-Peppas mathematical models. Controlled and prolonged (up to 432 h) 5-FU release profiles were observed for all examined hydrogels with first-order or zero-order kinetics. The drug release mechanism was generally denoted as non-Fickian transport.

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Section: Resultsmentioning

confidence: 99%

Hydrogels Based on Poly(Ether-Ester)s as Highly Controlled 5-Fluorouracil Delivery Systems—Synthesis and Characterization

et al. 2020

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“…On the basis of preliminary tests, zirconium (IV) acetylacetonate was selected as the most effective and nontoxic catalyst of the conducted reaction. In addition, it is known that this complex is not sensitive to any contaminants or traces of water and tends to be inert toward various chemicals at low temperatures, which allows polymerization of impure monomers, even in presence of organic acids [24,25].…”

Section: Synthesis and Characterization Of Obtained Grafted Dextrin Amentioning

confidence: 99%

Biodegradable Blends of Grafted Dextrin with PLGA-block-PEG Copolymer as a Carrier for Controlled Release of Herbicides into Soil

et al. 2020

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The presented work aimed to test influence of poly(L-lactide-co-glycolide)-block-poly (ethylene oxide) copolymer modification by blending with grafted dextrin or maltodextrin on the course of degradation in soil and the usefulness of such material as a matrix in the controlled release of herbicides. The modification should be to obtain homogenous blends with better susceptibility to enzymatic degradation. Among all tested blends, which were proposed as a carrier for potential use in the controlled release of plant protection agents, PLGA-block-PEG copolymer blended with grafted dextrin yielded very promising results for their future applications, and what is very importantly proposed formulations provide herbicides in unchanged form into soil within few months of release. The modification PLAGA/PEG copolymer by blending with modificated dextrins affects the improvement of the release profile. The weekly release rates for both selected herbicides (metazachlor and pendimethalin) were constant for a period of 12 weeks. Enzymatic degradation of modified dextrin combined with leaching of the degradation products into medium caused significant erosion of the polymer matrix, thereby leading to acceleration of water diffusion into the polymer matrix and allowing for easier leaching of herbicides outside the matrix.

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“…Polymerization was carried out in bulk with using zirconium(IV) acetylacetonate as a catalyst, a compound previously tested as an effective, non-toxic catalyst or initiator of the ROP reaction of lactides and lactones [18,19]. The choice of this catalyst was also driven by the fact that the compound was active in the ROP polymerization even in the presence of organic acids [20]. So, the use of such a catalyst guarantees the possibility of conducting polymerization in the presence of compounds containing carboxylate or carboxyl groups, which may be the reaction by-products.…”

Section: Synthesis and Characterization Of L-lactide Copolymers With mentioning

confidence: 99%

Synthesis and Properties of Bioresorbable Block Copolymers of l-Lactide, Glycolide, Butyl Succinate and Butyl Citrate

et al. 2020

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The paper presents the course of synthesis and properties of a series of block copolymers intended for biomedical applications, mainly as a material for forming scaffolds for tissue engineering. These materials were obtained in the polymerization of l-lactide and copolymerization of l-lactide with glycolide carried out using a number of macroinitiators previously obtained in the reaction of polytransesterification of succinic diester, citric triester and 1,4-butanediol. NMR, FTIR and DSC were used to characterize the materials obtained; wettability and surface free energy were assessed too. Moreover, biological tests, i.e., viability and metabolic activity of MG-63 osteoblast-like cells in contact with synthesized polymers were performed. Properties of obtained block copolymers were controlled by the composition of the polymerization mixture and by the composition of the macroinitiator. The copolymers contained active side hydroxyl groups derived from citrate units present in the polymer chain. During the polymerization of l-lactide in the presence of polyesters with butylene citrate units in the chain, obtained products of the reaction held a fraction of highly branched copolymers with ultrahigh molecular weight. The reason for this observed phenomenon was strong intermolecular transesterification directed to lactidyl side chains, formed as a result of chain growth on hydroxyl groups related to the quaternary carbons of the citrate units. Based on the physicochemical properties and results of biological tests it was found that the most promising materials for scaffolds formation were poly(l-lactide–co–glycolide)–block–poly(butylene succinate–co–butylene citrate)s, especially those copolymers containing more than 60 mol % of lactidyl units.

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Zirconium (IV) Acetylacetonate: Ring-Opening Initiator Mediating One-Step Synthesis of Biodegradable Polyacids

Cited by 13 publications

References 33 publications

Hydrogels Based on Poly(Ether-Ester)s as Highly Controlled 5-Fluorouracil Delivery Systems—Synthesis and Characterization

Hydrogels Based on Poly(Ether-Ester)s as Highly Controlled 5-Fluorouracil Delivery Systems—Synthesis and Characterization

Biodegradable Blends of Grafted Dextrin with PLGA-block-PEG Copolymer as a Carrier for Controlled Release of Herbicides into Soil

Synthesis and Properties of Bioresorbable Block Copolymers of l-Lactide, Glycolide, Butyl Succinate and Butyl Citrate

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