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Chemomechanical Polymers as Sensors and Actuators for Biological and Medicinal Applications.

Schneider HJ, Kato K, Strongin RM - Sensors (Basel) (2007)

Bottom Line: Two different effector molecules can induce motions as functions of their concentration, thus representing a logical AND gate.Another principle relies on the fast formation of covalent bonds between an effector and the chemomechanical polymer.The speed of the responses can significantly increase by increasing the surface to volume ratio of the polymer particles.

View Article: PubMed Central - PubMed

Affiliation: FR Organische Chemie der Universität des Saarlandes, D-66041 Saarbrücken, Germany.

ABSTRACT
Changes in the chemical environment can trigger large motions in chemomechanical polymers. The unique feature of such intelligent materials, mostly in the form of hydrogels, is therefore, that they serve as sensors and actuators at the same time, and do not require any measuring devices, transducers or power supplies. Until recently the most often used of these materials responded to changes in pH. Chemists are now increasingly using supramolecular recognition sites in materials, which are covalently bound to the polymer backbone. This allows one to use a nearly unlimited variety of guest (or effector) compounds in the environment for a selective response by automatically triggered size changes. This is illustrated with non-covalent interactions of effectors comprising of metal ions, isomeric organic compounds, including enantiomers, nucleotides, aminoacids, and peptides. Two different effector molecules can induce motions as functions of their concentration, thus representing a logical AND gate. This concept is particularly fruitful with effector compounds such as peptides, which only trigger size changes if, e.g. copper ions are present in the surroundings. Another principle relies on the fast formation of covalent bonds between an effector and the chemomechanical polymer. The most promising application is the selective interaction of covalently fixed boronic acid residues with glucose, which renders itself not only for sensing, but eventually also for delivery of drugs such as insulin. The speed of the responses can significantly increase by increasing the surface to volume ratio of the polymer particles. Of particular interest is the sensitivity increase which can be reached by downsizing the particle volume.

No MeSH data available.


a) Size changes of a PMMA-derived hydrogel (I, Scheme 1) as function of pH; calculated maximum volume change 390 % ; in 0.05M phosphate buffer (circles), and in 0.5M sodium chloride (triangles).; b) pH expansion profiles at different salt concentrations; in 0.5 M (●-a), 0.05 M(Δ-b), and 0.025 M(Ñ-c) sodium chloride solution, respectively, and in water with very dilute HCl or NaOH (▼-d;. Schneider, H. J.; Liu, T. J.; Lomadze, N. Molecular recognition in a supramolecular polymer system translated into mechanical motion. Angew. Chem.-Int. Edit. 2003, 42, 3544-3546. Copyright Wiley-VCH Verlag GmbH & Co. [39a].
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f1-sensors-07-01578: a) Size changes of a PMMA-derived hydrogel (I, Scheme 1) as function of pH; calculated maximum volume change 390 % ; in 0.05M phosphate buffer (circles), and in 0.5M sodium chloride (triangles).; b) pH expansion profiles at different salt concentrations; in 0.5 M (●-a), 0.05 M(Δ-b), and 0.025 M(Ñ-c) sodium chloride solution, respectively, and in water with very dilute HCl or NaOH (▼-d;. Schneider, H. J.; Liu, T. J.; Lomadze, N. Molecular recognition in a supramolecular polymer system translated into mechanical motion. Angew. Chem.-Int. Edit. 2003, 42, 3544-3546. Copyright Wiley-VCH Verlag GmbH & Co. [39a].

Mentions: The hydrogel I derived from the reaction of poly(methyl)methylacrylate (PMMA), diethylenetriamine and dodecylamine (Scheme 2) provides both pH-sensitive and lipophilic binding groups, It appears to be the only known gel which displays a symmetric pH profile above and below pH 7 (Figure 1) [39]. Xanthan-chitosan gels were reported to be sensitive not only to high pH with a maximum swelling at pH 10, but to some degree also at pH 0, where, however, the gel dissolves in the course of swelling [40].


Chemomechanical Polymers as Sensors and Actuators for Biological and Medicinal Applications.

Schneider HJ, Kato K, Strongin RM - Sensors (Basel) (2007)

a) Size changes of a PMMA-derived hydrogel (I, Scheme 1) as function of pH; calculated maximum volume change 390 % ; in 0.05M phosphate buffer (circles), and in 0.5M sodium chloride (triangles).; b) pH expansion profiles at different salt concentrations; in 0.5 M (●-a), 0.05 M(Δ-b), and 0.025 M(Ñ-c) sodium chloride solution, respectively, and in water with very dilute HCl or NaOH (▼-d;. Schneider, H. J.; Liu, T. J.; Lomadze, N. Molecular recognition in a supramolecular polymer system translated into mechanical motion. Angew. Chem.-Int. Edit. 2003, 42, 3544-3546. Copyright Wiley-VCH Verlag GmbH & Co. [39a].
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3814870&req=5

f1-sensors-07-01578: a) Size changes of a PMMA-derived hydrogel (I, Scheme 1) as function of pH; calculated maximum volume change 390 % ; in 0.05M phosphate buffer (circles), and in 0.5M sodium chloride (triangles).; b) pH expansion profiles at different salt concentrations; in 0.5 M (●-a), 0.05 M(Δ-b), and 0.025 M(Ñ-c) sodium chloride solution, respectively, and in water with very dilute HCl or NaOH (▼-d;. Schneider, H. J.; Liu, T. J.; Lomadze, N. Molecular recognition in a supramolecular polymer system translated into mechanical motion. Angew. Chem.-Int. Edit. 2003, 42, 3544-3546. Copyright Wiley-VCH Verlag GmbH & Co. [39a].
Mentions: The hydrogel I derived from the reaction of poly(methyl)methylacrylate (PMMA), diethylenetriamine and dodecylamine (Scheme 2) provides both pH-sensitive and lipophilic binding groups, It appears to be the only known gel which displays a symmetric pH profile above and below pH 7 (Figure 1) [39]. Xanthan-chitosan gels were reported to be sensitive not only to high pH with a maximum swelling at pH 10, but to some degree also at pH 0, where, however, the gel dissolves in the course of swelling [40].

Bottom Line: Two different effector molecules can induce motions as functions of their concentration, thus representing a logical AND gate.Another principle relies on the fast formation of covalent bonds between an effector and the chemomechanical polymer.The speed of the responses can significantly increase by increasing the surface to volume ratio of the polymer particles.

View Article: PubMed Central - PubMed

Affiliation: FR Organische Chemie der Universität des Saarlandes, D-66041 Saarbrücken, Germany.

ABSTRACT
Changes in the chemical environment can trigger large motions in chemomechanical polymers. The unique feature of such intelligent materials, mostly in the form of hydrogels, is therefore, that they serve as sensors and actuators at the same time, and do not require any measuring devices, transducers or power supplies. Until recently the most often used of these materials responded to changes in pH. Chemists are now increasingly using supramolecular recognition sites in materials, which are covalently bound to the polymer backbone. This allows one to use a nearly unlimited variety of guest (or effector) compounds in the environment for a selective response by automatically triggered size changes. This is illustrated with non-covalent interactions of effectors comprising of metal ions, isomeric organic compounds, including enantiomers, nucleotides, aminoacids, and peptides. Two different effector molecules can induce motions as functions of their concentration, thus representing a logical AND gate. This concept is particularly fruitful with effector compounds such as peptides, which only trigger size changes if, e.g. copper ions are present in the surroundings. Another principle relies on the fast formation of covalent bonds between an effector and the chemomechanical polymer. The most promising application is the selective interaction of covalently fixed boronic acid residues with glucose, which renders itself not only for sensing, but eventually also for delivery of drugs such as insulin. The speed of the responses can significantly increase by increasing the surface to volume ratio of the polymer particles. Of particular interest is the sensitivity increase which can be reached by downsizing the particle volume.

No MeSH data available.