In order to create polymers that are responsive to changes in temperature, metal cations can be used. When the temperature changes, the metal cations will bind to the molecules in the polymer, causing the polymer to change shape. This change in shape can be used to create materials that are responsive to changes in temperature. These materials can be used in a variety of applications, including in medical devices and in electronic devices.
In recent years, with the continuous development of intelligent or “smart” materials, the application of these materials in various fields has gradually increased. Smart materials are able to sense and respond to external stimuli such as temperature, light, magnetic field, electric field, pressure and humidity. Among them, thermoresponsive polymers are one of the most studied and investigated groups of smart materials. When the temperature of the surrounding environment changes, the aggregation state or conformation of the thermoresponsive polymer changes accordingly, giving rise to remarkable physicochemical changes. As one of the thermoresponsive polymers, metal cation-recognizable thermoresponsive polymers are a new type of thermoresponsive polymer with potential application in the field of drug delivery.
Under physiological conditions, the majority of drugs exist in insoluble form and cannot be taken up by cells. In order to improve the bioavailability of these drugs, a delivery system is required to transport the drug to the target site. Metal cation-recognizable thermoresponsive polymers can be used as drug carriers because of their unique structure and function. The polymer consists of a linear poly(N-isopropylacrylamide) (PNIPAM) backbone with pendant groups that can specifically recognize and bind to metal cations. When the temperature is below the lower critical solution temperature (LCST) of the polymer, the polymer is in a hydrophilic state and can surround and solubilize the drug. Above the LCST, the polymer undergoes a transition to a hydrophobic state, which leads to the release of the drug. This temperature-responsive behaviour makes the metal cation-recognizable thermoresponsive polymer an ideal drug delivery system, as the drug can be released at the desired site by simply controlling the temperature.
In addition, the metal cation-recognizable thermoresponsive polymer can be modified to change its drug release behaviour. For example, the addition of a charged group to the polymer backbone can cause the polymer to transition to the hydrophobic state at a lower temperature, while the addition of a long chain alkyl group can delay the transition to the hydrophobic state. This allows for greater control over the drug release, which is an important factor in determining the efficacy of the drug delivery system.
The metal cation-recognizable thermoresponsive polymer is a new type of thermoresponsive polymer with potential application in the field of drug delivery. This polymer has the ability to specifically bind to metal cations and release the drug at a desired site by simply controlling the temperature. The metal cation-recognizable thermoresponsive polymer can be modified to change its drug release behaviour, giving it potential to be used in a wide range of applications.