# Airborne delivery of microbots for chemical and mechanical attack of pulmonary biofilms

> **NIH NIH R21** · COLORADO SCHOOL OF MINES · 2020 · $190,589

## Abstract

Project Summary: In cystic fibrosis (CF), treatment is difficult because chronic lung infections
lead to biofilm formation and drug-resistant bacterial strains prevent antibiotics from working
effectively. Antibiotic approaches specifically designed to address infections in the lung include
inhaled antibiotics; however, resistant strains are a significant challenge. For delivery, such
inhaled drugs must be formulated within a specified size range. Too large and they do not
remain suspended to reach deep within the lungs. Too small and they remain in the air and are
simply exhaled without embedding. Our scientific premise is that individual magnetic particles of
this optimal size range can be inhaled into the lungs and subsequently assembled in place in
the form of wheel-like assemblies, or µwheels, to travel deep down lung pathways and disrupt
mucus layers to enhance drug-induced biofilm removal. As both µwheel assembly and driving
forces are provided by an external magnetic field, once the procedure is finished, devices “self-
disassemble” into small building blocks removable by the body's natural mechanism for removal
of dust and other foreign particles in the mucus lining. Our aims include: Aim 1: Identify applied
magnetic field conditions that promote µwheel-enhanced biofilm degradation. We will study
model P. aeruginosa and CF patient-derived biofilms, with and without artificial sputum, and
attach antibiotics or dispersal agents onto the magnetic particle surface and within tortuous
microenvironments. We will also use nanoparticle-decorated µwheels to perforate and penetrate
the film and test with antibiotic/dispersal agent in solution. Aim 2: Determine conditions that
support airborne delivery and transport of µwheels in 3D environments. We will demonstrate
airborne delivery of µwheels and translation within 3D models of patient respiratory systems,
with and without artificial sputum.

## Key facts

- **NIH application ID:** 9828617
- **Project number:** 5R21AI138214-02
- **Recipient organization:** COLORADO SCHOOL OF MINES
- **Principal Investigator:** DAVID WM MARR
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $190,589
- **Award type:** 5
- **Project period:** 2018-11-23 → 2023-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9828617

## Citation

> US National Institutes of Health, RePORTER application 9828617, Airborne delivery of microbots for chemical and mechanical attack of pulmonary biofilms (5R21AI138214-02). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/9828617. Licensed CC0.

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