Novel Hydrogels for Rhythmic Pulsatile Drug Delivery

Mujumdar, Siddharthya K.; Bhalla, Amardeep S.; Siegel, Ronald A.

doi:10.1002/masy.200790081

Cited by 2 publications

(2 citation statements)

References 15 publications

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“…The pH response of these hydrogels was attenuated compared to conventionally crosslinked NIPA/acrylic acid or NIPA/methacrylic acid hydrogels 43. Also, optical clarity of the double network hydrogels was significantly compromised compared to the NC hydrogels synthesized with NIPA alone.…”

Section: Discussionmentioning

confidence: 95%

Introduction of pH‐sensitivity into mechanically strong nanoclay composite hydrogels based on N‐isopropylacrylamide

Mujumdar

Siegel

2008

J. Polym. Sci. A Polym. Chem.

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AbstractpH-sensitive nanoclay composite hydrogels based on N-isopropylacrylamide (NIPA) were synthesized by copolymerization with cationic and anionic comonomers. Laponite nanoclay particles served as multifunctional crosslinkers, producing hydrogels with exceptionally high mechanical strengths, as measured by elongation at break. Cationic copolymer gels based on NIPA and dimethylaminoethylmethacrylate were prepared by aqueous free radical polymerization, adopting a procedure reported by Haraguchi (Adv Mater 2002, 14, 1120-1124. Without modification, this technique failed to produce anionic copolymer gels of NIPA and methacrylic acid due to flocculation of clay particles. Three methods were conceived to incorporate acidic MAA into nanoclay hydrogels. First, NIPA was copolymerized with acidic comonomer under dilute conditions, producing hydrogels with good pH-sensitivity but weak mechanical characteristics. Second, NIPA was copolymerized with methyl methacrylate, which was then hydrolyzed to generate acid sidegroups, yielding hydrogels that were much stronger but less pH sensitive. Third, NIPA was copolymerized with an acid comonomer following modification of the nanoclay surface with pyrophosphate ions. The resulting hydrogels exhibited both strong pHsensitivities at 37 °C and excellent tensile properties. Optical transparency changed during polymerization, depending on hydrophobicity of the components. This work increases the diversity and functionality of nanoclay hydrogels, which display certain mechanical advantages over conventionally crosslinked hydrogels.

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Section: Discussionmentioning

confidence: 95%

Introduction of pH‐sensitivity into mechanically strong nanoclay composite hydrogels based on N‐isopropylacrylamide

Mujumdar

Siegel

2008

J. Polym. Sci. A Polym. Chem.

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“…The remarkable feature of the BZ gels 8 9 is that they are the only known polymer networks that undergo periodic swelling and deswelling in the absence of external stimuli and an imposed flow. (Other remarkable examples of oscillating gels include pH-responsive systems based on the bromate–sulfite (BS) reaction that undergo oscillations in a continuously-stirred tank reactor 10 or gel-based oscillators that occur due to a chemo-mechanical feedback mechanisms in multi-component systems such as hydrogel-enzyme oscillators 11 12 13 or self-regulating, homeostatic materials 14 .) When Ru(bpy) 3 is grafted to a poly(NIPAAm) gel and the material is immersed in a solution of BZ reagents, the ensuing chemical reaction provides the fuel for this BZ gel's rhythmic mechanical oscillations.…”

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confidence: 99%

Designing Dual-functionalized Gels for Self-reconfiguration and Autonomous Motion

Kuksenok

Balazs

2015

Sci Rep

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Human motion is enabled by the concerted expansion and contraction of interconnected muscles that are powered by inherent biochemical reactions. One of the challenges in the field of biomimicry is eliciting this form of motion from purely synthetic materials, which typically do not generate internalized reactions to drive mechanical action. Moreover, for practical applications, this bio-inspired motion must be readily controllable. Herein, we develop a computational model to design a new class of polymer gels where structural reconfigurations and internalized reactions are intimately linked to produce autonomous motion, which can be directed with light. These gels contain both spirobenzopyran (SP) chromophores and the ruthenium catalysts that drive the oscillatory Belousov-Zhabotinsky (BZ) reaction. Importantly, both the SP moieties and the BZ reaction are photosensitive. When these dual-functionalized gels are exposed to non-uniform illumination, the localized contraction of the gel (due to the SP moieties) in the presence of traveling chemical waves (due to the BZ reaction) leads to new forms of spontaneous, self-sustained movement, which cannot be achieved by either of the mono-functionalized networks.

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Novel Hydrogels for Rhythmic Pulsatile Drug Delivery

Cited by 2 publications

References 15 publications

Introduction of pH‐sensitivity into mechanically strong nanoclay composite hydrogels based on N‐isopropylacrylamide

Introduction of pH‐sensitivity into mechanically strong nanoclay composite hydrogels based on N‐isopropylacrylamide

Designing Dual-functionalized Gels for Self-reconfiguration and Autonomous Motion

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