Effects of Poly(Propylene Oxide)–Poly(Ethylene Oxide)–Poly(Propylene Oxide) Triblock Copolymer on the Gelation of Poly(Ethylene Oxide)–Poly(Propylene Oxide)–Poly(Ethylene Oxide) Aqueous Solutions

Xie, Yu; Tang, Jiankai; Lu, Zhong‐Yuan; Sun, Zhaoyan; An, Lijia

doi:10.1080/00222348.2012.758524

Cited by 9 publications

(12 citation statements)

References 37 publications

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“…Consistent with prior reports, , in the first step, P407 micelles are formed while 25R4 chains remain in solution. As proposed by Xie et al, these low-molecular-weight 25R4 chains hinder interactions among neighboring P407 micelles and thus prevent gelation. In the second step, as temperature is increased further, the PPO blocks in 25R4 dehydrate to form multichain bridges across P407 micelles. , These bridges serve as additional physical cross-links, leading to an increase in the maximum storage modulus ( G ′ max ) upon 25R4 addition. ,, This rheological enhancement remains in drug-loaded formulations, providing a mechanism for improving the stability of gels that suffer from low gelation moduli with drug addition. , While neat RPs with lower PEO fractions do not form micelles in water, the addition of 31R1, an RP with 10% PEO, to P407 solutions also enhances G ′ max but reduces T onset .…”

Section: Introductionmentioning

confidence: 86%

Engineering the Structure and Rheological Properties of P407 Hydrogels via Reverse Poloxamer Addition

et al. 2023

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Aqueous solutions of poloxamer 407 (P407), a commercially available and nontoxic ABA triblock polymer (PEO-PPO-PEO), undergo a solution-to-gel transition with increasing temperature and are promising candidates for injectable therapeutics. The gel transition temperature, modulus, and structure are all dictated by polymer concentration, preventing independent tuning of these properties. Here, we show that addition of BAB reverse poloxamers (RPs) to P407-based solutions dramatically alters the gelation temperature, modulus, and morphology. Gelation temperature and RP localization within the hydrogel are dictated by RP solubility. Highly soluble RPs increase gelation temperature and incorporate primarily into the micelle corona regions. Alternatively, RPs with low aqueous solubility decrease gelation temperature and associate within the micelle core and core−corona interface. These differences in RP localization have significant implications for the hydrogel modulus and microstructure. The ability to tune gelation temperature, modulus, and structure through RP addition allows for the design of thermoresponsive materials with specific properties that are unobtainable with neat P407-based hydrogels.

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Section: Introductionmentioning

confidence: 86%

Engineering the Structure and Rheological Properties of P407 Hydrogels via Reverse Poloxamer Addition

et al. 2023

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“…429 In addition, micellization and gelation of poloxamer/reverse poloxamer mixtures have been investigated suggesting a critical composition ratio above which the appearance of bridged poloxamer micelles strongly impedes the gelation process. 430,431 The spectrum of applications for reverse poloxamers, however, appears to be limited in comparison to "normal" poloxamers. This is probably attributed to their unfavorable self-assembly.…”

Section: Chemical Reviewsmentioning

confidence: 99%

“…In addition, micellization and gelation of poloxamer/reverse poloxamer mixtures have been investigated suggesting a critical composition ratio above which the appearance of bridged poloxamer micelles strongly impedes the gelation process. , …”

Section: Block Copolymers Of Peg and Ppomentioning

confidence: 99%

Polymerization of Ethylene Oxide, Propylene Oxide, and Other Alkylene Oxides: Synthesis, Novel Polymer Architectures, and Bioconjugation

et al. 2015

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The review summarizes current trends and developments in the polymerization of alkylene oxides in the last two decades since 1995, with a particular focus on the most important epoxide monomers ethylene oxide (EO), propylene oxide (PO), and butylene oxide (BO). Classical synthetic pathways, i.e., anionic polymerization, coordination polymerization, and cationic polymerization of epoxides (oxiranes), are briefly reviewed. The main focus of the review lies on more recent and in some cases metal-free methods for epoxide polymerization, i.e., the activated monomer strategy, the use of organocatalysts, such as N-heterocyclic carbenes (NHCs) and N-heterocyclic olefins (NHOs) as well as phosphazene bases. In addition, the commercially relevant double-metal cyanide (DMC) catalyst systems are discussed. Besides the synthetic progress, new types of multifunctional linear PEG (mf-PEG) and PPO structures accessible by copolymerization of EO or PO with functional epoxide comonomers are presented as well as complex branched, hyperbranched, and dendrimer like polyethers. Amphiphilic block copolymers based on PEO and PPO (Poloxamers and Pluronics) and advances in the area of PEGylation as the most important bioconjugation strategy are also summarized. With the ever growing toolbox for epoxide polymerization, a "polyether universe" may be envisaged that in its structural diversity parallels the immense variety of structural options available for polymers based on vinyl monomers with a purely carbon-based backbone.

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“…TIM test, as described earlier [ 44 , 45 , 46 ], was performed to visually confirm the gelation phenomenon. A 5.0 mL aliquot of each formulation was transferred to a clear glass vial and sealed tightly.…”

Section: Methodsmentioning

confidence: 99%

Poloxamer 407-Based Thermosensitive Emulgel as a Novel Formulation Providing a Controlled Release of Oil-Soluble Pharmaceuticals—Ibuprofen Case Study

2021

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This article covers the design and evaluation of a novel drug vehicle: a thermosensitive, injectable, high-oil-content (50% w/w) emulgel providing a controlled release of lipophilic pharmaceuticals. Different vegetable (castor, canola, olive, peanut, grapeseed, linseed), mineral (paraffin) and semisynthetic (isopropyl myristate, oleic acid) oils were screened for ibuprofen (IBU) solubility and for their capacity for high-shear emulsification in a 17% (w/w) aqueous solution of poloxamer 407. Chosen emulgels were subject to a rheological evaluation, a syringeability test (TA.XT texture analyser; 2 mL syringe; 18 G, 20 G and 22 G needles) and a drug release study (48 h; cellulose membrane; 0.05 mol/L phosphate buffer at pH 7.4). Castor oil turned out to be an optimal component for IBU incorporation. Blank and drug-loaded castor oil emulgels were susceptible to administration via a syringe and needle, with the absolute injection force not exceeding 3 kg (29.4 N). The drug release test revealed dose-dependent, quasi-linear kinetics, with up to 44 h of controlled, steady, linear release. The results indicate the significant potential of high-oil-content, oil-in-water thermosensitive emulgel formulations as vehicles for the controlled release of lipophilic APIs.

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Effects of Poly(Propylene Oxide)–Poly(Ethylene Oxide)–Poly(Propylene Oxide) Triblock Copolymer on the Gelation of Poly(Ethylene Oxide)–Poly(Propylene Oxide)–Poly(Ethylene Oxide) Aqueous Solutions

Cited by 9 publications

References 37 publications

Engineering the Structure and Rheological Properties of P407 Hydrogels via Reverse Poloxamer Addition

Engineering the Structure and Rheological Properties of P407 Hydrogels via Reverse Poloxamer Addition

Polymerization of Ethylene Oxide, Propylene Oxide, and Other Alkylene Oxides: Synthesis, Novel Polymer Architectures, and Bioconjugation

Poloxamer 407-Based Thermosensitive Emulgel as a Novel Formulation Providing a Controlled Release of Oil-Soluble Pharmaceuticals—Ibuprofen Case Study

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