# Circulating Red Blood Cell Based Nanosensors for Continuous, Real-Time Drug Monitoring

> **NIH NIH R01** · NORTHEASTERN UNIVERSITY · 2020 · $353,250

## Abstract

PROJECT SUMMARY
In this project we will develop new technology for non-invasive and continuous therapeutic drug
monitoring. Drug dosing is normally prescribed based on population averages, but in most cases
direct clinical testing of systemic drug levels is performed infrequently or not at all. This is particularly
problematic for drugs with narrow therapeutic indices, where treatment can be ineffective or outright
toxic. Therefore, there is a persistent need for new technology for routine drug monitoring to allow
better therapeutic outcomes while minimizing side-effects.
We propose to address this problem by developing drug-sensitive fluorescent nanosensors that will
use circulating red blood cell (RBC) ghosts as a vehicle to remain in circulations. By using near-
infrared fluorophores at high local concentrations, these will produce drug-dependent signals that will
be measurable with an external optical reader. Because unmodified RBCs are known to stay in
circulation for weeks or months, this will allow long-term, continuous monitoring directly in the
peripheral blood. Although there are many potential uses for this technology, we will first develop it for
monitoring lithium and sodium as examples of a prescribed drug and its toxic side-effect.
The project has three main phases. First we will design fluorescent red blood cell (f-RBC)
nanosensors that circulate stably in the blood stream. These will encapsulate novel fluorescent
sensor constructs for accurate quantification of Lithium and sodium blood concentrations. Second, we
will develop an f-RBC fluorescence reader that for non-invasive and accurate quantification of f-RBC
signals in vivo without having to draw blood samples. The reader will measure circulating f-RBC
sensors in major blood vessels in the forearm in diffuse reflectance configuration. Third, we will
validate and optimize our f-RBC sensor and reader in optical flow-phantom models in vitro and in rats
treated with lithium and a diuretic in vivo.
Longer term, we anticipate that there will be many uses for our f-RBC nanosensor technology for
personalized therapeutic dose monitoring in many areas of medicine. The technology could also be
extended to monitor effects on downstream drug targets in the future.

## Key facts

- **NIH application ID:** 9820730
- **Project number:** 5R01EB024186-03
- **Recipient organization:** NORTHEASTERN UNIVERSITY
- **Principal Investigator:** Heather A Clark
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $353,250
- **Award type:** 5
- **Project period:** 2018-02-01 → 2021-11-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9820730

## Citation

> US National Institutes of Health, RePORTER application 9820730, Circulating Red Blood Cell Based Nanosensors for Continuous, Real-Time Drug Monitoring (5R01EB024186-03). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/9820730. Licensed CC0.

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