# Combined RNA Production and Purification Reagents Using Liquid-Liquid Phase Separating Biopolymers

> **NIH NIH R43** · ISOLERE BIO, INC. · 2021 · $255,516

## Abstract

Project Summary
The goal of this Phase I SBIR project is to develop a novel purification method that is compatible with in vitro
transcription (IVT)-based manufacturing of RNA for use as a therapeutic or vaccine. As RNA becomes more
commonly used for pharmaceutical products, manufacturing methods must improve their scalability, speed, and
cost-effectiveness. There are several pain points in RNA manufacturing. First, current affinity resins have very
low capacity —only ~2mg RNA per mL— necessitating large volumes of resin at commercial scale. These resins
are priced at over $25,000 per liter, rendering commercial scale production extremely costly. Second, 5’ capping
of RNA – essential for in vivo function – and the subsequent removal of any residual uncapped RNA is a major
bottleneck for RNA production. Isolere Bio, Inc. specializes in designing innovative purification solutions that
combine a protein affinity tag that is genetically fused to an elastin-like polypeptide (ELP). This reagent is capable
of temperature or salt-controlled phase separation that enables capture of a specific target regardless of its
complexity or the presence of other impurities. We will develop a novel combination of biopolymers, referred to
here as IVTag™, that enables simultaneous RNA sequestration into concentrated, pure liquid droplets and
methylation of transcripts. Two ELP fusion proteins will be developed: one will contain an RNA-binding motif and
the second an O’-methyltransferase (O’-MTase) enzyme, responsible for 5’-capping of RNA. We will then
develop platform methods for simultaneous purification of RNA into droplets and high efficiency capping of the
sequestered RNA. This Phase I program is designed to demonstrate compatibility of this essential IVT enzyme
and complexing it with Isolere’s non-chromatographic purification methods. Key activities of the proposal include
synthesizing, purifying, and testing each biopolymer fusions’ functionality and then evaluating their efficacy when
applied in tandem and comparing process efficiency to the industry standard method. If successful, additional
functionality of the RNA micro-crucible will be developed in Phase II in the form of a T7 polymerase-ELP fusion
(for initial transcription of a DNA template) and a Poly-A polymerase-ELP fusion (for adding a 3’ poly-A tail to
transcripts). Our vision is to ultimately create a fully continuous RNA manufacturing process in smart droplets.
These smart droplets are expected to support a straightforward, scalable, and cost-effective manufacturing
workflow with micro-crucibles capable of carrying out a complex series of processing steps. Because the micro-
crucible is volume independent, the scale-up difficulties associated with affinity resins are eliminated. In addition,
with other applications of Isolere’s technology, including to antibodies and viral vectors, the ELP fusion reagents
have proven to be easily manufacturable and re-usable for multiple purification cycles, reduc...

## Key facts

- **NIH application ID:** 10325210
- **Project number:** 1R43GM143975-01
- **Recipient organization:** ISOLERE BIO, INC.
- **Principal Investigator:** Michael James Dzuricky
- **Activity code:** R43 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $255,516
- **Award type:** 1
- **Project period:** 2021-09-15 → 2022-12-14

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10325210

## Citation

> US National Institutes of Health, RePORTER application 10325210, Combined RNA Production and Purification Reagents Using Liquid-Liquid Phase Separating Biopolymers (1R43GM143975-01). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10325210. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*