Ultrasonic Permeation of Stimuli-Responsive Microgels through Porous Media as a Model Process for Drug Transfer

• Applicant: Dr. Seyedamin Rahimzadeh
• Subject Area: Polymer Materials
• Term: from 2021 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 460540240

Needle-free drug delivery (NFDD) systems drive a specific amount of a drug into the site of delivery, bypassing the hypodermic needle with a reusable option. Achieving a successful drug delivery depends on the ability to make the liquid jet and accelerate it while no harm is done to the skin or the integrity of drug molecules. The primary goal of the proposed research is to utilize high-frequency ultrasonic (MHz-order) waves to form a thin liquid jet from microgel aqueous solutions and permeate through a simulated porous tissue. Poly(N-isopropylacrylamide) (PNIPAM) microgels, which are thermo-responsive and undergo a volume phase transition at 32 °C, will be used as the model system for drug carriers. Formation of a stable liquid jet that contains swollen PNIPAM microgels on the one hand and its ability to penetrate through the porous tissue, on the other hand, are the most important objectives of the proposed research. A secondary goal is to introduce and investigate the high-frequency acoustic waves as a novel stimulus for PNIPAM microgels. It was shown in preliminary experiments that upon low enough excitation amplitude, the liquid-air interface does not experience the jet formation. Hence, the solution has sufficient time to absorb adequate energy for breaking the hydrogen bonds and PNIPAM microgels undergo a volume phase transition due to the absorption of acoustic energy instead of thermal energy. This opens up a new research direction in contrast to jet formation using ultrasonic actuation.

• DFG Programme: WBP Position