Novel pH-sensitive polymers containing sulfonamide groups

Park, Sang Yeob; Bae, You Han

doi:10.1002/(sici)1521-3927(19990501)20:5<269::aid-marc269>3.0.co;2-3

Cited by 107 publications

(52 citation statements)

References 22 publications

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“…It has been well established in the literature that a sulfonamide group in a polymer chain carries its pH activity. [17][18][19][20] The physicochemical properties of the micelle were investigated in terms of micelle size, critical micelle concentration (CMC) and pH sensitivity by monitoring the fluorescence of pyrene at different pH levels. The hydrophobic drug paclitaxel was loaded into the pH sensitive micelle using a solvent free protocol, and drug release behaviors were studied in vitro.…”

Section: Introductionmentioning

confidence: 92%

Novel pH Sensitive Block Copolymer Micelles for Solvent Free Drug Loading

Shim

Kim

Choi

et al. 2006

Macromolecular Bioscience

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Novel pH sensitive biodegradable block copolymers (MPEG-PDLLA-OSM) composed of mono-methoxy poly(ethylene glycol) (MPEG), poly (D,L-lactide) (PDLLA) and sulfamethazine oligomer (OSM) were synthesized via ring-opening polymerization and a dicyclohexyl carboimide (DCC) coupling reaction. These copolymers had a relatively low critical micelle concentration (CMC) due to the strong hydrophobic properties of non-ionized OSM at pH 7.0. Also, the pH sensitive block copolymers showed the micelle-unimer transition due to the ionization-non-ionization of OSM in the pH range (pH 7.2-8.4) above the CMC. Due to the pH sensitive properties of the block copolymer, the hydrophobic drug paclitaxel (PTX) was incorporated into a pH sensitive block copolymer micelle by the pH induced micellization method, without using an organic solvent. The block copolymer micelle prepared by pH induced micellization showed a relatively high PTX loading efficiency, and good stability for 2 d at 37 degrees C. Furthermore, the PTX loaded micelle showed a sustained release of PTX with a small burst in vitro over 2 d. The present results suggest that the pH induced micellization method due to the micelle-unimer transition of the pH sensitive block copolymer would be a novel and valuable drug incorporation tool for hydrophobic and protein drugs, since no organic solvent is involved in the formulation.

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Section: Introductionmentioning

confidence: 92%

Novel pH Sensitive Block Copolymer Micelles for Solvent Free Drug Loading

Shim

Kim

Choi

et al. 2006

Macromolecular Bioscience

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“…Synthesis of OSA: OSA was synthesized as previously described [24]. First, SA (10 mmol) was dissolved in a NaOH/acetone mixture (40 mL; NaOH (0.5 N; aqueous (aq.…”

Section: Methodsmentioning

confidence: 99%

pH‐Tunable Endosomolytic Oligomers for Enhanced Nucleic Acid Delivery

Kang

Bae

2007

Adv Funct Materials

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Oligomeric sulfonamides (OSAs) are explored as a tool for the effective endosomal release of polyplexes or delivery of nucleic acid. The OSAs tested in this study show varying proton‐buffering regions and pH‐dependent solubility transitions within the endosomal pH range, and are influenced by the pKa value and hydrophobicity of a given sulfonamide group. In addition, OSA presents negligible toxicity. The oligomers are added to the nucleic acid solution for polyplex formation with positively charged polymeric nucleic acid carriers. The resulting nanoscale, positively charged, and OSA‐incorporated poly(L‐lysine) (PLL)/DNA complexes (OSA‐polyplexes) show a 4–55‐fold increase in in vitro gene expression compared to PLL/DNA (control), depending upon the cell line and the nature of the used OSA. In cellular uptake and intracellular trafficking studies using pH‐sensitive or pH‐insensitive dye‐labeled DNAs, there is no significant difference in the amount of DNA uptake using OSA polyplexes and PLL/DNA. However, OSA–polyplexes induce a broader intracellular distribution of the DNA than PLL/DNA complexes do. These results, coupled with the enhanced DNA transfection using OSA–polyplexes, indicate a mechanism by which OSA induces endosomal release of polyplexes and/or nucleic acids. The findings suggest that OSA could enhance polymer‐based nucleic acid delivery. Furthermore, such materials offer significant potential for effective cytosolic delivery of chemical, biological, and diagnostic therapeutics.

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“…Moreover, lipase immobilization was achieved within the self-assembling of the synthesized carriers, a larger particle size would lead to a higher immobilization efficiency owing to the occurrence of embedding and adsorption. introduction of sulfadimethoxine (SDM), a member of the sulfonamide family, which is an important factor responsible for the polymer pH sensitivity [23]. In an acidic environment, SDM was deionized and became hydrophobic, which led to a strong self-assembling of the pullulan derivatives.…”

Section: Particle Characterization and Ph Responsibilitymentioning

confidence: 99%

Immobilized Burkholderia cepacia Lipase on pH-Responsive Pullulan Derivatives with Improved Enantioselectivity in Chiral Resolution

Cui

et al. 2018

Catalysts

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Abstract:A kind of pH-responsive particle was synthesized using modified pullulan polysaccharide. The synthesized particle possessed a series of merits, such as good dispersity, chemical stability and variability of particle size, making it a suitable carrier for enzyme immobilization. Then, Burkholderia cepacia lipase (BCL), a promising biocatalyst in transesterification reaction, was immobilized on the synthesized particle. The highest catalytic activity and immobilization efficiency were achieved at pH 6.5 because the particle size was obviously enlarged and correspondingly the adsorption surface for BCL was significantly increased. The immobilization enzyme loading was further optimized, and the derivative lipase was applied in chiral resolution. Under the optimal reaction conditions, the immobilized BCL showed a very good performance and significantly shortened the reaction equilibrium time from 30 h of the free lipase to 2 h with a conversion rate of 50.0% and ee s at 99.2%. The immobilized lipase also exhibited good operational stability; after being used for 10 cycles, it still retained over 80% of its original activity. Moreover, it could keep more than 80% activity after storage for 20 days at room temperature in a dry environment. In addition, to learn the potential mechanism, the morphology of the particles and the immobilized lipase were both characterized with a scanning electron microscope and confocal laser scanning microscopy. It was found that the enlarged spherical surface of the particle in low pH values probably led to high immobilized efficiency, resulting in the improvement of enantioselectivity activity in chiral resolution.

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Novel pH-sensitive polymers containing sulfonamide groups

Cited by 107 publications

References 22 publications

Novel pH Sensitive Block Copolymer Micelles for Solvent Free Drug Loading

Novel pH Sensitive Block Copolymer Micelles for Solvent Free Drug Loading

pH‐Tunable Endosomolytic Oligomers for Enhanced Nucleic Acid Delivery

Immobilized Burkholderia cepacia Lipase on pH-Responsive Pullulan Derivatives with Improved Enantioselectivity in Chiral Resolution

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