# Controlled-release Microbeads to Replace Growth Factors in Fetal Bovine Serum

> **NIH NIH R42** · STEMCULTURES, LLC · 2024 · $826,379

## Abstract

Scientific Abstract:
The frequent use of fetal bovine serum (FBS) to support cell cultures is challenged by lot-to-lot variability, supply
constraints, pathogen contaminants and ethical questions. These issues have increased significance due to the
burgeoning use of FBS in cell research and therapy development. FBS has been used for over a century to
culture cells, but with the need to define culture conditions for efficient manufacturing, along with modern
approaches to control delivery of key molecules, many of the problems associated with FBS use can now be
alleviated. The need to reduce animal products is critically important, as is the need to use human growth factors
to optimize human cell growth. The company StemCultures specializes in controlling the growth factor (GF)
component of cell culture media. Our goal is to replace FBS GFs with a bioengineered DISCTM (Defined Insert
for Sustainable Culture) device providing controlled-release human recombinant GFs. The advanced cell
manufacturing DISCTM device will address concerns about FBS and improve the reproducibility of cell production.
In this application we will develop a DISCTM device for growth of human retinal pigment epithelial (RPE) cells.
Human RPE was selected as a testbed for FBS replacement as these cells are a vanguard for stem cell
replacement therapy in the US, Europe and Asia. A barrier to reducing FBS use is the lack of knowledge about
the GF content of FBS that is critical for growth of the RPE cell product. We will measure levels of FBS GFs that
stimulate human RPE cell proliferation. Selected recombinant human GFs will be encapsulated in controlled-
release GF microbeads that provide a standardized growth signal over time, to replace the variable levels of
bovine GFs provided by FBS with defined levels of native human recombinant GFs. The GF microbeads will be
assessed in a factorial design experiment to identify microbead combinations that support RPE cell growth at a
reduced level of FBS. The microbead combination that supports RPE cell growth without FBS or at the lowest
level of FBS will be packaged in a Defined Insert for Sustainable Culture (DISCTM) device to simplify RPE cell
manufacture. The DISCTM will be manufactured as a commercial product marketed to reduce FBS dependence
of the commercially important RPE cells. Future work will apply the microbead/DISCTM platform strategy to
reduce FBS dependence of other cell types. The company StemCultures (SCL) routinely manufactures
microbeads and DISCsTM for sustained release of GFs in culture media and the co-located Neural Stem Cell
Institute (NSCI) has extensive RPE cell culture expertise. The SCL-NSCI collaboration successfully completed
Phase 1 aims, in preparation to make Phase 2 goals highly feasible.

## Key facts

- **NIH application ID:** 10806135
- **Project number:** 5R42GM142345-03
- **Recipient organization:** STEMCULTURES, LLC
- **Principal Investigator:** Kristina Roberts
- **Activity code:** R42 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $826,379
- **Award type:** 5
- **Project period:** 2023-04-01 → 2026-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10806135

## Citation

> US National Institutes of Health, RePORTER application 10806135, Controlled-release Microbeads to Replace Growth Factors in Fetal Bovine Serum (5R42GM142345-03). Retrieved via AI Analytics 2026-05-26 from https://api.ai-analytics.org/grant/nih/10806135. Licensed CC0.

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