# Encapsulated platelets in cast hydrogels (EPIC) to measure single platelet structure-function relationships in old age

> **NIH NIH R21** · UNIVERSITY OF COLORADO DENVER · 2021 · $233,250

## Abstract

PROJECT SUMMARY
A critical challenge laid out in the NHLBI Strategic Vision is the development of single-cell analytics to assess
health and resiliency. An area where single-cell methods are lacking is in the measurement of platelet
reactivity. Specifically, the link between structural heterogeneity and function heterogeneity in platelets is
poorly defined. This is a problem because platelets are regulators of bleeding, thrombotic, and inflammatory
disorders, and we lack markers of resilience against these disorders. The long-term goal of this line of research
is to develop technology that can reveal the mechanistic links between structural and functional heterogeneity
in blood cells. The overall objective of this proposal, which is the first step along this continuum of research, is
to develop an analytical approach to measure the relationships between mitochondria mass and RNA content
and agonist-induced activation at the single platelet level and use that approach to measure changes from
individuals from young to old age. Additionally, this approach should allow for pulsatile presentation of agonists
because studies in other cells have shown pulsatile stimuli can synchronize response, better identifying
subpopulations, and detect low and high frequency band pass filters in signal transduction. The rationale for
this approach is that most clinical assays of platelet function measure ensembles of platelets that are unable to
discriminate the role of different platelet subpopulations, nor are they able to tie structure and function at the
single cell level. We will meet our overall objective with two specific aims: 1) Fabricate and test encapsulated
platelets in cast (EPIC) hydrogels to quantify single cell structural and functional heterogeneity; and 2)
Measure changes in platelet structure and function with age. We will develop a hydrogel-based platform to
rapidly encapsulate fresh platelet isolates and measure the number of organelles or RNA content and correlate
these measures with intracellular calcium dynamics and activation markers in response to pulsatile
presentation of agonist(s). Using the EPIC platform, we will measure platelet structure and functional changes
in platelet from childhood to old age in both sexes. We will test the hypothesis that mitochondrial mass
increases with age and correlates with platelet hyperactivity. These studies will be compared to a
comprehensive set of platelet phenotyping assays including platelet aggregometry, microfluidic flow assays,
flow cytometry, and bioenergetics. The proposed research is innovative, in our opinion, because it represents a
substantive departure from the status quo by developing a platform for studying thousands of single platelets in
response to dynamic (temporally-modulated) stimuli in minutes. These contributions will be significant because
they are expected to provide the means to study normal biological function in platelets in terms of their ability to
sense, integrate, and re...

## Key facts

- **NIH application ID:** 10126899
- **Project number:** 5R21HL152350-02
- **Recipient organization:** UNIVERSITY OF COLORADO DENVER
- **Principal Investigator:** Keith B Neeves
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $233,250
- **Award type:** 5
- **Project period:** 2020-04-01 → 2023-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10126899

## Citation

> US National Institutes of Health, RePORTER application 10126899, Encapsulated platelets in cast hydrogels (EPIC) to measure single platelet structure-function relationships in old age (5R21HL152350-02). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10126899. Licensed CC0.

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