Ultrasonic Permeation of Stimuli-Responsive Microgels through Porous Media as a Model Process for Drug Transfer
Final Report Abstract
As the primary goal of this project, we achieved successful utilization of high-frequency surface acoustic waves (SAWs) to generate a jet from poly(N-Isopropylacrylamide) (PNIPAM) microgel dispersions. Through our research, we demonstrated that the mechanical properties of microgels, particularly their softness, play a critical role in controlling the stability of the formed jet, despite its rapid formation (in milliseconds). Our findings revealed that microgels possess the ability to rearrange themselves at the extended water-air interface, thereby maintaining the integrity of the jet. Furthermore, we observed that this response becomes more pronounced as the microgels become softer. This understanding of the relationship between microgel softness and their response at the water-air interface opens up new possibilities for applications in fields such as microfluidics, drug delivery, and surface engineering. As the secondary goal of our research, we introduced high-frequency ultrasound as a novel stimulus for poly(N-Isopropylacrylamide) (PNIPAM). Through our investigations, we demonstrated the acousto-response of linear PNIPAM and examined its kinetics, which was found to be influenced by both the ultrasound frequency and the solution concentration. Additionally, we successfully combined dynamic light scattering (DLS) with ultrasound to characterize the system using compact silica particles as a preliminary step for characterizing PNIPAM microgel size under the influence of ultrasound. Our results showed that PNIPAM microgels are indeed acousto-responsive and exhibit much faster kinetics compared to temperature-induced changes. These findings are significant as they offer new insights into the behavior of PNIPAM microgels under ultrasound stimulation, and they highlight the potential of high-frequency ultrasound as a non-invasive and efficient stimulus for applications such as drug delivery, smart materials, and responsive devices.
Publications
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Visualization of Acoustic Energy Absorption in Confined Aqueous Solutions by PNIPAM Microgels: Effects of Bulk Viscosity. Langmuir, 37(19), 5854-5863.
Rahimzadeh, Amin; Rutsch, Matthias; Kupnik, Mario & Klitzing, Regine von
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Frequency-Dependent Ultrasonic Stimulation of Poly(N-Isopropylacrylamide) Microgels in Water. Gels, 8(10), 628.
Razavi, Atieh; Rutsch, Matthias; Wismath, Sonja; Kupnik, Mario; von Klitzing, Regine & Rahimzadeh, Amin
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Impact of Ultrasound on the Motion of Compact Particles and Acousto-responsive Microgels. Research Square Platform LLC.
Stock, Sebastian; von Klitzing, Regine & Rahimzadeh, Amin
