Drug release profile of dissolving sugar-based untethered magnetic robot

The research investigates the drug release kinetics of untethered magnetic robots (UMRs), specifically focusing on dissolvable sugarbased UMRs, these UMRs are currently being developed. While the  goal is to deliver drugs to  places like obstructed vessels, traditional UMRs carry risks. To solve this, degradable sugar-based UMRs are used that mitigate the danger of getting stuck. This UMR is designed to dissolve in 5-10 minutes when in the bloodstream. The dissolving of the UMR acts as a drug release mechanism for the drug encapsulated in the UMR. Currently the drug release profile is underdefined, this research will focus on the visualising and charactering of this mechanism. Visualisation will be achieved by optical imaging of the released dye. Quantitative characterisation will be achieved by downstream periodic sampling of the fluorescence marker; this fluorescence marker is used to achieve precise quantification of the release rate.

For these experiments 2 experimental set-ups will be created. Set-up 1 consists of a pump which creates a constant flow in a closed system of saline solution. A certain spot in the tubing will have the rotating magnet above the tube which will keep the UMR in the same position, a camera will then image the drug (in this case dye) release of the UMR. Building on the visual data from set-up 1, Set-up 2 uses fluorescence dye encapsulated inside the UMR. As the UMR degrades periodic sampling of the fluorescence dye will be collected to measure the fluorescence intensity in Arbitrary Units (A.U.). By comparing these values to a calibration series, the intensity can be converted into a concentration. This way the drug release profile can be plotted.

If time allows, the research can be extend with two follow-up experiments focused on drug retention in obstructed vessels. The first experiment uses a parallel flow system with 2 tubes one containing a simulated clot and one unobstructed tube. The UMR will be steered magnetically to be close to the clot then the release of dye is imaged optically. The other tube will have no obstruction and act as other parallel blood vessels. The second experiment will have the same setup but imaged using CT-scanner and contrast agent.