Chemical coatings can affect microparticles 'swimming' in mucus solutions, study shows

The joint research, "Spontaneous symmetry breaking propulsion of chemically coated magnetic microparticles," has been published in Scientific Reports.

Designing specialized surface coatings to generate specific propulsion properties will provide new approaches to drug delivery strategies, the study concludes. Being able to navigate microparticles quickly will support drug deployment when delivery speed is critical for patient recovery. In addition, being able to precisely navigate these "swimming" microparticles will allow them to travel through complex fluids and tissue environments to targeted locations in the human body.

"Thanks to SMU's partnership, we will continue to push the boundaries of microrobotics research and look forward to sharing our ongoing work with the scientific community," said Louis William Rogowski, lead microrobotics investigator at ARA. "We are honored to have our joint research published in Scientific Reports."

Rogowski, Kim and their team members were able to demonstrate that changing the surface chemistry of microparticles can dynamically change propulsion behavior.

"We are excited to see the feasibility of chemically coated magnetic microparticles for precise navigation in bodily fluidic environments," said Kim, the Robert C. Womack Chair in SMU's Lyle School of Engineering and principal investigator of the BAST Lab. "We will continue to work together to develop a new type of microrobotics for targeted drug delivery systems."

For this study, biotin, Biotin-PEG3-amine and biotin chitosan were chemically applied to the surface of microparticles. Coated microparticles were then suspended in mucus synthesized from porcine stomach mucins (glycoproteins found in mucus) and navigated with rotating magnetic fields using a spontaneous symmetry breaking propulsion mechanism. The surface coatings altered the propulsion behavior of microparticles, depending on both magnetic field properties and localized mucus properties.

Next steps, say the researchers, include coating microparticles with an actual pharmaceutical compound and measuring uptake within live environments using "swarms" of microparticles, or examining cellular membrane interactions. Designing specialized surface coatings to generate specific propulsion properties will also provide new approaches to drug delivery strategies. The authors hope the study will increase interest into microparticle-based propulsion mechanisms and help provide novel innovations to targeted drug delivery applications.