Structural Biochemistry/Drug Platform
Different administration of drugs is to enhance the drug effects on the body, depending on the symptom of the patient. Below is an illustration showing therapeutic window. The goal and the challenge of the researchers is to minimize the drug toxicity to the body and to maximize the drug activity inside the body. In order to keep the drug concentration inside of blood at the therapeutic window, a sustainable drug release is desired. To achieve this, many nanotechnology drug platforms are available. The most common ones are liposomes and hydrogels.
Hydrogel can encapsulate drugs inside its core. When the environment changes, the hydrogel is able to swell, which causes the release of drug.
Types of hydrogel
Acidic or basic hydrogel
change in pH causes swelling causes release of drug
change in ionic strength causes change in concentration of ions inside the gel causes change in swelling causes release of drug
hydrogel containing electron-accepting groups
Electron-donating compounds causes formation of charge and transfer complex causes change in swelling causes the release of drug.
Hydrogel containing immobilized enzymes
A substrate is present, and enzymatic conversion causes the product the change and swell, which causes the release of drug.
Magnetic particles disperse in alginate microshapes
A magnetic field is applied to change the pores in gel to change in swelling and thus release of drug.
A change in temperature causes change in polymer-polymer and water-polymer interactions that changes the shape of hydrogel and causes the release of drug.
An electric field is applied that causes the membrane the charge and causes the electrophoresis of charged drug and change the shape of hydrogel to release the drug
Ethylene-vinyl alcohol hydrogel
Untralsound irradiation is used to increase the temperature to cause the hydrogel to swell to release the drug.
Zhang, Liangfang. "Controlled Drug Delivery Systems." CENG 207 Lecture 11. University of California, San Diego, La Jolla. 10 May 2012. Lecture.