# Antimicrobial blue light-activatable optical endotracheal tube to combat biofilms on the endotracheal tube

> **NIH NIH R21** · MASSACHUSETTS GENERAL HOSPITAL · 2024 · $205,735

## Abstract

PROJECT SUMMARY/ABSTRACT
Endotracheal intubation is a common hospital procedure implemented in patients requiring mechanical
ventilation. However, biofilms formed on endotracheal tubes (ETTs) represent a leading cause of ventilator-
associated pneumonia (VAP). VAP affects up to 28% of intubated patients and carries a 13% overall mortality.
Efforts to prevent VAP have included systemic antibiotics and silver-coated ETTs. However, systemic
antibiotics are reported to have little effect on biofilm formation on ETTs. Although silver‐coated ETTs have
been shown to reduce the VAP rate effectively, these tubes have a major limitation in being economically
feasible. Therefore, there is a critical need to develop new strategies that can effectively eradicate biofilms on
ETTs and are also cost-effective. The objective of this R21 application is to explore the utility of a novel
optical endotracheal tube (Optical-ETT), which can be activated by antimicrobial blue light (aBL; 405 nm)
and subsequently emit aBL uniformly from the ETT surface, to combat biofilms on ETTs. Our team is a pioneer
in the field of aBL. Our central hypothesis is that Optical-ETT can effectively prevent biofilm formation and
eradicate preexisting biofilm on the ETT. To address this hypothesis, we propose two Specific Aims.
In Aim 1, we will conduct in vitro studies to determine the anti-biofilm efficacy of Optical-ETT. Biofilms will be
formed on ETT segments in the growth medium. To prevent biofilm formation on ETTs, Optical-ETTs will be
"activated" by aBL within 3 h after bacterial inoculation. To eradicate preexisting biofilms on ETTs, Optical-
ETTs will be "activated" by aBL 24, 48, and 96 h after bacterial inoculation when biofilms of different stages
have formed. The efficacy found with Optical-ETTs will be compared with that of silver-coated ETTs.
In Aim 2, we will determine the anti-biofilm efficacy and safety of Optical-ETT in vivo using a swine model of
endotracheal intubation. Animals will be challenged by instilling bacterial suspensions (5 mL at 108 CFU/mL)
into the buccal pouch 30 min after intubation. To prevent biofilm formation on ETTs, Optical-ETTs will be
activated by aBL within 3 h after bacterial challenge. To eradicate preexisting biofilms on ETTs, the activation
of Optical-ETTs by aBL will be delayed until 24 h after bacterial challenge when mature biofilms have formed.
The bacterial loads of ETTs, the tracheas, and the lungs will be quantified. To evaluate the safety of Optical-
ETT, the tracheal tissue damages will be assessed using histology. The potential inflammatory response
triggered by Optical-ETT will be analyzed by measuring the proinflammatory cytokine profile in the
bronchoalveolar lavage fluid. Additionally, the effect of Optical-ETT on the ciliary motion will be evaluated using
micro-optical coherence tomography, a unique imaging technology invented in our department.
The most important impact of this application resides in the opening of a branch of...

## Key facts

- **NIH application ID:** 10789259
- **Project number:** 1R21AI180632-01
- **Recipient organization:** MASSACHUSETTS GENERAL HOSPITAL
- **Principal Investigator:** Lorenzo Berra
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $205,735
- **Award type:** 1
- **Project period:** 2024-08-02 → 2026-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10789259

## Citation

> US National Institutes of Health, RePORTER application 10789259, Antimicrobial blue light-activatable optical endotracheal tube to combat biofilms on the endotracheal tube (1R21AI180632-01). Retrieved via AI Analytics 2026-06-12 from https://api.ai-analytics.org/grant/nih/10789259. Licensed CC0.

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