Rapid Deswelling Response of Poly(<i>N</i>-isopropylacrylamide) Hydrogels by the Formation of Water Release Channels Using Poly(ethylene oxide) Graft Chains

Kaneko, Yuzo; Nakamura, Satoki; Sakai, Kiyotaka; Aoyagi, Takaaki; Kikuchi, Akihiko; Sakurai, Yasuhisa; Okano, Teruo

doi:10.1021/ma971899g

Cited by 342 publications

(302 citation statements)

References 33 publications

(77 reference statements)

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“…However, most of the polymers which exhibit coil-globule transition possess dubious biocompatibility and biodegradation [20]. Moreover, the LCST of these polymers are often not appropriate for hyperthermia application and must be adjusted by copolymerisation with other hydrophilic or hydrophobic moieties, which may negatively affect their thermosensitive behaviour [21]. The LCST may also depend on the nature and molar concentration of the co-monomers [22], solvent quality [23], and co-solvents or additives present in the solution [24].…”

Section: Discussionmentioning

confidence: 99%

Low-melting-point polymeric nanoshells for thermal-triggered drug release under hyperthermia condition

Dabbagh

Mahmoodian

Abdullah

et al. 2015

International Journal of Hyperthermia

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Purpose: The aim of this paper was to synthesise core-shell nanostructures comprised of mesoporous silica core and a low melting-point polyethylene glycol (PEG) nanoshell with a sharp gel-liquid phase transition for rapid drug release at hyperthermia temperature range. Materials and methods:The phase transition behaviours of PEGs with molecular weights of 1000, 1500, and 2000 Da were analysed using differential scanning calorimetry (DSC) to determine the optimal formulation with phase transition in the hyperthermia range. The 'graftto' method was employed to synthesise core-shell nanostructures using the selected PEG formulation. The drug loading and release behaviours of these nanocarriers were examined by ultra-violet visible spectroscopy (UV-Vis) using doxorubicin as a model drug. Magnetic resonance-guided focused ultrasound (MRgFUS) was also applied as a typical thermal modality to evaluate the rate of drug release from the core-shell nanostructures. Results: The PEG molecular weight of 1500 Da presented the optimal phase transition temperature for thermaltriggered release under hyperthermia conditions. Drug release measurements at different temperatures using UV-Vis methods showed a 20.2 ± 4.3% leakage in aqueous solution at 37 C after 30 min, while this value was significantly increased to 68.2 ± 3.7% at 50 C. A 45.5 ± 3.1% drug release was also obtained after sonication of the drug-loaded nanoparticles for 5 Â 20 s using MRgFUS. Conclusion: Although the ratio of drug leakage at physiological temperatures was relatively high, the sharp transition temperature, high loading efficiency, and fast drug release at hyperthermia temperature range could make these core-shell nanoparticles prominent for enhancing the efficacy of various hyperthermia modalities in the treatment of cancer tumours.

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Section: Discussionmentioning

confidence: 99%

Low-melting-point polymeric nanoshells for thermal-triggered drug release under hyperthermia condition

Dabbagh

Mahmoodian

Abdullah

et al. 2015

International Journal of Hyperthermia

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“…Several years ago, our laboratory reported the comb-type grafted PIPAAm hydrogel [40,41]. Poly(ethylene glycol) (PEG) chains were grafted into a PIPAAm cross-linked network by co-polymerization of IPAAm and PEG macromonomer, which has been prepared by the etherification reaction of alpha-hydroxy-omega-methoxy-PEG with acryloyl chloride.…”

Section: Poly(n-isopropylacrylamide) Co-grafted With Poly(ethylene Glmentioning

confidence: 99%

Temperature-Responsive Polymer Modified Surface for Cell Sheet Engineering

2012

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Abstract:In the past two decades, as a novel approach for tissue engineering, cell sheet engineering has been proposed by our laboratory. Poly(N-isopropylacrylamide) (PIPAAm), which is a well-known temperature-responsive polymer, has been grafted on tissue culture polystyrene (TCPS) surfaces through an electron beam irradiated polymerization. At 37 °C, where the PIPAAm modified surface is hydrophobic, cells can adhere, spread on the surface and grow to confluence. By decreasing temperature to 20 °C, since the surface turns to hydrophilic, cells can detach themselves from the surface spontaneously and form an intact cell sheet with extracellular matrix. For obtaining a temperature-induced cell attachment and detachment, it is necessary to immobilize an ultra thin PIPAAm layer on the TCPS surfaces. This review focuses on the characteristics of PIAPAm modified surfaces exhibiting these intelligent properties. In addition, PIPAAm modified surfaces giving a rapid cell-sheet recovery has been further developed on the basis of the characteristic of the PIPAAm surface. The designs of temperature-responsive polymer layer have provided an enormous potential to fabricate clinically applicable regenerative medicine.

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“…In this respect, a simple method was used to synthesize two crosslinkers based on polyfunctional acrylate and methacrylate [20]. The chemical structures of the prepared crosslinkers were elucidated by FT IR, 1 H NMR and 13 C NMR. The ability to use these new crosslinkers to synthesize a novel series of porous crosslinked polymers is important for the objective of this work.…”

Section: Chemical Structures Of the Networkmentioning

confidence: 99%

“…As previously described [13], melamine (0.1 mole) was dissolved in NMP (100 ml) at room temperature for 24 h. The solution was transferred into a four-necked flask fitted with a mechanical stirrer, thermometer, nitrogen inlet and dropping funnel. Triethyl amine (0.3 mole) was added to the solution.…”

Section: Synthesis and Purification Of N-melamine Acrylamide Crosslinmentioning

confidence: 99%

Synthesis and Characterization of Porous Crosslinked Copolymers for Oil Spill Sorption

et al. 2007

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Cinnamoyloxy ethyl methacrylate (CEMA) was copolymerized with different monomer feed ratios of octadecyl acrylate (ODA) and crosslinked using azobisisobutyronitrile (AIBN) as the initiator and N,N',N"-trisacryloyl melanine (AM) or N,N',N",-trismethacryloylmelanine (MM) crosslinkers. The networks are characterized by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA). For crosslinked CEMA/ODA copolymer sol fraction values are lower when MM is used rather than AM. The thermal stability of crosslinked network increases with increasing ODA concentration and also in the presence of MM crosslinker, a consequence of higher crosslinking density. SEM results show a porous structure; micropores are formed when ODA contents increases. According to DMA results, the flexibility of the network is enhanced by incorporation of MM rather than AM. Since our crosslinked networks are both flexible and porous, they are applicable as oil sorber networks to alleviate pollution from oil spills.

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Rapid Deswelling Response of Poly(N-isopropylacrylamide) Hydrogels by the Formation of Water Release Channels Using Poly(ethylene oxide) Graft Chains

Cited by 342 publications

References 33 publications

Low-melting-point polymeric nanoshells for thermal-triggered drug release under hyperthermia condition

Low-melting-point polymeric nanoshells for thermal-triggered drug release under hyperthermia condition

Temperature-Responsive Polymer Modified Surface for Cell Sheet Engineering

Synthesis and Characterization of Porous Crosslinked Copolymers for Oil Spill Sorption

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