Molecular dynamics and crystallization in polymers based on ethylene glycol methacrylates (EGMAs) with melt memory characteristics: from linear oligomers to comb-like polymers

Vassiliadou, Olga; Chrysostomou, Varvara; Pispas, Stergios; Klonos, Panagiotis Α.; Kyritsis, Apostolos

doi:10.1039/d0sm01666g

Cited by 18 publications

(13 citation statements)

References 66 publications

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“…We would like to point out that relaxation of the side chains is likely frozen in at significantly lower temperatures as reported for polymethacrylates with oligoethylene glycol side chains, which feature a b-relaxation temperature below À100 1C. 26 To rule out that the chain length of p(g 4 2T-T) strongly influences the T g we also studied a low-molecular weight fraction collected through fractionation of the as-synthesized polymer with acetone. DMA of the acetone fraction of p(g 4 2T-T) revealed a T g E À51 1C, which is only marginally lower than the T g E À46 1C of p(g 4 2T-T) with M n E 24 kg mol À1 (Fig.…”

Section: Resultsmentioning

confidence: 99%

Tuning of the elastic modulus of a soft polythiophene through molecular doping

et al. 2022

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Section: Resultsmentioning

confidence: 99%

Tuning of the elastic modulus of a soft polythiophene through molecular doping

et al. 2022

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“…Variation of the number of ethylene glycol (EG) repeated units, and therefore the length of the side chains can impact on the properties of OEGMA-based polymers. For instance, OEGMAs with short side chains (less than nine repeated units of ethylene glycol) present thermoresponsive behavior [ 20 , 22 ], while OEGMAs with long side chains provide increased solubility and enhanced stealth and shielding properties [ 23 , 24 ].…”

Section: Introductionmentioning

confidence: 99%

Hydrophilic Random Cationic Copolymers as Polyplex-Formation Vectors for DNA

et al. 2022

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Research on the improvement and fabrication of polymeric systems as non-viral gene delivery carriers is required for their implementation in gene therapy. Random copolymers have not been extensively utilized for these purposes. In this regard, double hydrophilic poly[(2-(dimethylamino) ethyl methacrylate)-co-(oligo(ethylene glycol) methyl ether methacrylate] [P(DMAEMA-co-OEGMA)] random copolymers were synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization. The copolymers were further modified by quaternization of DMAEMA tertiary amine, producing the cationic P(QDMAEMA-co-OEGMA) derivatives. Fluorescence and ultraviolet–visible (UV–vis) spectroscopy revealed the efficient interaction of copolymers aggregates with linear DNAs of different lengths, forming polyplexes, with the quaternized copolymer aggregates exhibiting stronger binding affinity. Light scattering techniques evidenced the formation of polyplexes whose size, molar mass, and surface charge strongly depend on the N/P ratio (nitrogen (N) of the amine group of DMAEMA/QDMAEMA over phosphate (P) groups of DNA), DNA length, and length of the OEGMA chain. Polyplexes presented colloidal stability under physiological ionic strength as shown by dynamic light scattering. In vitro cytotoxicity of the empty nanocarriers was evaluated on HEK293 as a control cell line. P(DMAEMA-co-OEGMA) copolymer aggregates were further assessed for their biocompatibility on 4T1, MDA-MB-231, MCF-7, and T47D breast cancer cell lines presenting high cell viability rates.

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“…This relaxation was revealed only via the performed analysis. To the best of our knowledge, this is the first time that this is reported for IND. ,− At first we assumed that the overall characteristics of α* resemble those of the so-called Normal Mode process, which is recorded, in general, in short chains of high mobility and is proposed to arise from the chain end to end dipole moment . Interestingly, however, the α* in the present study disappears when the hydrogels are evaluated.…”

Section: Resultsmentioning

confidence: 49%

High-Drug-Loading Amorphous Solid Dispersions via In Situ Thermal Cross-Linking: Unraveling the Mechanisms of Stabilization

et al. 2021

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This article takes a step forward in understanding the mechanisms involved during the preparation and performance of cross-linked high-drug-loading (HDL) amorphous solid dispersions (ASDs). Specifically, ASDs, having 90 wt % poorly water-soluble drug indomethacin (IND), were prepared via in situ thermal cross-linking of poly(acrylic acid) (PAA) and poly(vinyl alcohol) (PVA) and thoroughly evaluated in terms of physical stability and in vitro supersaturation. Results showed that HDL ASDs having excellent active pharmaceutical ingredient (API) amorphous stability and prolonged in vitro supersaturation were prepared by fine tuning the cross-linking procedure. Unraveling of the processes involved during ASD’s formation shed light on the significant role of the cross-linking conditions (i.e., temperature and time), the physicochemical properties of the API, and the hydrolysis level of the cross-linker as key factors in modulating ASD’s stability. In-depth analysis of the prepared systems revealed the (1) reduction of API’s molecular motions within the cross-linked polymeric networks (through API’s strong spatial confinement), (2) the structural changes in the prepared cross-linked matrices (induced by the high API drug loading), and (3) the tuning of the cross-linking density via utilization of low-hydrolyzed PVA as the major mechanisms responsible for ASD’s exceptional performance. Complementary analysis by means of molecular dynamics simulations also highlighted the vital role of strong drug–polymer intermolecular interactions evolving among the ASD components. Overall, the impression of the complexity of in situ cross-linked ASDs has been reinforced with the excessive variation of parameters investigated in the current study, offering thus insights up to the submolecular level to lay the groundwork and foundations for the comprehensive assessment of a new emerging class of HDL amorphous API formulations.

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Molecular dynamics and crystallization in polymers based on ethylene glycol methacrylates (EGMAs) with melt memory characteristics: from linear oligomers to comb-like polymers

Abstract: In this article we present results on the glass transition, crystallization and molecular dynamics in relatively novel oligomers, oligo-ethylene glycol methacrylate (OEGMA), with short and long chains, as well as...

Cited by 18 publications

References 66 publications

Tuning of the elastic modulus of a soft polythiophene through molecular doping

Tuning of the elastic modulus of a soft polythiophene through molecular doping

Hydrophilic Random Cationic Copolymers as Polyplex-Formation Vectors for DNA

High-Drug-Loading Amorphous Solid Dispersions via In Situ Thermal Cross-Linking: Unraveling the Mechanisms of Stabilization

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