Study shows chemical coatings can affect microparticles 'swimming' in mucus solutions

Study shows chemical coatings can affect microparticles 'swimming' in mucus solutions
Overview of experimental setup and magnetic field interactions. (a) Avidin coated magnetic microparticles are functionalized with one of three compounds: biotin, Biotin-PEG3-amine, or biotin chitosan. Functionalized microparticles are suspended in a 4% mucin solution and loaded into a sample chamber which is placed in the middle of an approximate Helmholtz coil system. Programmable power supplies and camera visualization are used to navigate microparticles through the mucus with rotating magnetic fields. Chemical structures were extracted from Chemspyder and HAworks. (b) Magnetic fields produced from the Helmholtz coil system and their relationship to Eqs. (1–3). When torqued by a magnetic field, a microparticle in a rod-climbing-like fluid will propel along a propulsion axis perpendicular to its plane of symmetry. Two propulsion states can be achieved (U+,U) randomly when no static field is applied (Bs = 0). Either propulsion state can be selected at will when a non-zero static field is applied (Bs ≠ 0). Red and blue hemispheres represent magnetic dipoles. Credit: Scientific Reports (2022). DOI: 10.1038/s41598-022-21725-z

Collaborative research between SMU nanorobotics authority MinJun Kim's Biological Actuation, Sensing, and Transport (BAST) Lab and international research and engineering company ARA has demonstrated for the first time that certain chemical coatings, applied to micro/nanoparticles, can alter their swimming propulsion within biological fluids.

The joint research 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 ," 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 properties and localized mucus properties.

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

More information: Louis William Rogowski et al, Spontaneous symmetry breaking propulsion of chemically coated magnetic microparticles, Scientific Reports (2022). DOI: 10.1038/s41598-022-21725-z

Journal information: Scientific Reports

Citation: Study shows chemical coatings can affect microparticles 'swimming' in mucus solutions (2022, November 22) retrieved 4 December 2022 from
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