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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.


Expansion of hydrogels by uptake of guest molecules G and of water for solvation.
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f15-sensors-07-01578: Expansion of hydrogels by uptake of guest molecules G and of water for solvation.

Mentions: Sensors are increasingly being used for monitoring changes in environmental conditions in a fully automated manner. This includes detecting the levels of chemical compounds in living systems. In most applications, a sensing unit is only one component of an operating system which responds to the sensor signal by a predetermined action, e.g. by correcting the pH of a medium by adding neutralizing agents. A unique feature of chemomechanical polymers is that they function simultaneously as both sensors and actuators. These intelligent materials can be designed to respond to changes in external conditions via macroscopic or microscopic motions, which may then be used to control electric circuits or to open or close, e.g., vessels for the release or uptake of different agents. The major advantage in comparison to traditional control systems is that chemomechanical polymers can operate without any additional devices such as transducers or transmitters, and without any external power supply. These new materials can be fabricated in a variety of ways, down to the micro- or nano scale, or as thin films, to afford the added advantages of enhanced sensitivity and speed of response. The field is expected to expand considerably after chemists have, in the framework of supramolecular chemistry, developed the principles of molecular recognition, which, until now have been studied mainly in solution [1]. Smart materials, into which suitable recognition sites are incorporated, hold much promise for a manifold of applications [2], including drug delivery [3], detoxification, control of biological functions in the body, artificial muscles [4], etc. Scheme 1 illustrates the mechanisms involved in expansion of hydrogels by the uptake of guest molecules G which bind non-covalently to acceptor sites A,B,C, etc., on the polymer backbone.


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

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

Expansion of hydrogels by uptake of guest molecules G and of water for solvation.
© Copyright Policy
Related In: Results  -  Collection

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

f15-sensors-07-01578: Expansion of hydrogels by uptake of guest molecules G and of water for solvation.
Mentions: Sensors are increasingly being used for monitoring changes in environmental conditions in a fully automated manner. This includes detecting the levels of chemical compounds in living systems. In most applications, a sensing unit is only one component of an operating system which responds to the sensor signal by a predetermined action, e.g. by correcting the pH of a medium by adding neutralizing agents. A unique feature of chemomechanical polymers is that they function simultaneously as both sensors and actuators. These intelligent materials can be designed to respond to changes in external conditions via macroscopic or microscopic motions, which may then be used to control electric circuits or to open or close, e.g., vessels for the release or uptake of different agents. The major advantage in comparison to traditional control systems is that chemomechanical polymers can operate without any additional devices such as transducers or transmitters, and without any external power supply. These new materials can be fabricated in a variety of ways, down to the micro- or nano scale, or as thin films, to afford the added advantages of enhanced sensitivity and speed of response. The field is expected to expand considerably after chemists have, in the framework of supramolecular chemistry, developed the principles of molecular recognition, which, until now have been studied mainly in solution [1]. Smart materials, into which suitable recognition sites are incorporated, hold much promise for a manifold of applications [2], including drug delivery [3], detoxification, control of biological functions in the body, artificial muscles [4], etc. Scheme 1 illustrates the mechanisms involved in expansion of hydrogels by the uptake of guest molecules G which bind non-covalently to acceptor sites A,B,C, etc., on the polymer backbone.

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.