# Damage-Free, Ultrasonic Cell Isolation from Retinal Pigment Epithelium (RPE) Monolayers

> **NIH NIH R01** · UNIVERSITY OF SOUTHERN CALIFORNIA · 2023 · $566,755

## Abstract

Abstract
Age-related macular degeneration (AMD) is the leading cause of severe visual impairment in people over age
50 in developed countries [1,2]. Transplantation of stem cell derived retinal pigment epithelium (RPE) is
currently a promising method to treat retinal degeneration and advanced non-neovascular AMD (NNAMD) [3-
6]. Many protocols have been developed for the derivation of RPE from pluripotent stem cells from human
embryonic stem cells (hESC) or human induced pluripotent stem cell (iPSC) [7-12]. The quality control of
donor cells is a basic requirement for cell production in clinical trials. Stem cell residues and chromosome
number variation during long-term culture must be tested before clinical use. However, quality control for stem
cell residues (pluripotency) and stem cell tumorigenicity is not trivial. Physically removing cells from an RPE
monolayer during culture will result in hypotrophy of the monolayer due to epithelial-mesenchymal transition
(EMT) and wound healing. There is an unmet need in the molecular profiling of RPE implants with spatial
RNA sequencing (RNA-seq). A focused ultrasound (FUS) offers a solution to this unmet need, as it can
produce ejection of cells via cell-containing liquid droplets from a solid surface with minimum impact on the
edges surrounding the ejection spot. Ultrasound propagates through liquid and solid, and the FUS transducer
does not have to be in physical contact with the substrate where cells are grown. The number of cells that are
ejected by a FUS transducer depends on the focal size of the FUS, which can be very small, and is very
precise and repeatable. Further, it is low-cost and effective for isolating tens to hundreds of single-cells in
parallel through an array of transducers. To satisfy the unmet need and allow realization of RPE cell therapy
for AMD, we propose to use self-focusing acoustic transducers (SFATs) for damage-free, cell-containing
droplet ejection from RPE monolayers grown on thin solid scaffolds for spatial single-cell RNA-seq. Besides
for quality control in RPE implant production, the SFAT’s unprecedented capability of on-demand ejection of
microparticles or cells (of tens - hundreds of microns in diameter) will open up many new possibilities in
spatial molecular cell study, gene transfection, juxtaposition and manipulation.

## Key facts

- **NIH application ID:** 10717828
- **Project number:** 1R01EY035281-01
- **Recipient organization:** UNIVERSITY OF SOUTHERN CALIFORNIA
- **Principal Investigator:** EUN SOK KIM
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2023
- **Award amount:** $566,755
- **Award type:** 1
- **Project period:** 2023-08-01 → 2027-02-28

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10717828

## Citation

> US National Institutes of Health, RePORTER application 10717828, Damage-Free, Ultrasonic Cell Isolation from Retinal Pigment Epithelium (RPE) Monolayers (1R01EY035281-01). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10717828. Licensed CC0.

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