Haritosh wins Young Investigator Award at Bioengineering & Translational Medicine Conference!

Haritosh presented his work on "Tunable and Deployable Drug Eluting Stent with Passive Bimodal Drug Release" at the 8th Annual Translational Medicine and Bioengineering Conference, a subdivision of AiCHE. Olivia Snapper started working on this project as an MRSEC REU student and is continuing working with Haritosh on the development of drug-eluting stents as a Research Fellow in the group.

Abstract: Implanted medical devices must withstand the foreign body response, risking infection, blood clotting, or malfunction. We propose a drug-eluting stent with a slippery liquid-infused porous surface (SLIPS) on a TiNi base substrate. This alloy's superelastic properties allow it to deform during surgery and return to its shape after deployment, making it ideal for minimally invasive applications like brain aneurysms and heart stents. The coating's multilayer nanoparticle system creates a porous matrix, infused with a biocompatible lubricant to repel pathogens and cellular debris. We demonstrate the SLIPS coating’s adherence on TiNi substrates, showcasing omniphobic repellency and mechanical stability. This system reduces infection risk post-surgery, increases device patency, and improves flow within the conduit. Additionally, TiNi-SLIPS devices can be drug-loaded for treatments like antibiotics, anti-inflammatory drugs, or cancer molecules. We confirmed multilayer deposition stability on TiNi, with SEM images showing an amorphous, porous structure. The average particle size was 13.620 nm ± 2.431 nm (n=15) with 18.46% free space. Surface repellency was measured using static contact angle, contact angle hysteresis, and sliding angle with deionized water and DMSO. Non-SLIPS TiNi samples showed significant pinning, with high contact angle hysteresis and droplet removal failure after a 25° tilt. Deionized water had a 112.6° ± 10.0° contact angle and >36.6° ± 12.7° CAH. Post-lubrication with silicone oil (350 cP), the TiNi substrate had a 94.9° ± 7.3° contact angle, 4.2° ± 5.3° CAH, and 4.4° ± 5.2° sliding angle, confirming high repellency. Our initial tests have also demonstrated tunability of the drug delivery kinetics using various oil-infused viscosity and loading types. Our method applies SLIPS to a biocompatible, shape memory, and superelastic alloy, potentially reducing restenosis and thrombosis complications, and can be used in coronary and carotid stents.