---
title: "nCage Therapeutics — Programmable synthetic protein cages"
description: "nCage Therapeutics builds TRAP-cages: synthetic virus-like particles that display antigens on their surface and open on command to release cargo inside the cell."
url: https://www.ncage.org/en
language: en
site: nCage Therapeutics
---

# A protein cage that opens on command

> nCage Therapeutics is developing a novel synthetic protein cage based on the bacterial TRAP protein

Protein cages are synthetic virus-like particles (VLPs). They display biological material on their surface, and carry molecules such as nucleic acids or proteins into the interior of the cell.

## What are TRAP-cages?

TRAP-cages are protein cages formed from rings of the bacterial TRAP protein. They act like a virus — displaying biological material on their surface, or transporting nucleic acids and proteins into the cell — without carrying any genetic material of their own.

### Synthetic virus-like particles

- Formed by multiple copies of modified or de novo protein components, designed to assemble into stable, hollow shapes.
- Built on the bacterial TRAP protein.
- Akin to synthetic viral particles, but without nucleic material.
- The exterior carries mounted protein or other biological material.
- Proteins can be mounted in repeating arrays, mimicking the patterns found in nature.

### Programmable opening

- Programmable opening and closing is unique to the TRAP-cage platform.
- Cargo is loaded into the interior of the cage and released inside cells.
- Cargo can be proteins, peptides, nucleic acids or small molecule drugs.

_Figure: TRAP-cage structure. Twenty-four protein rings held at their vertices by gold(I) ions, shown in yellow._

## Loaded shut. Opened on cue.

- **Closed** — Gold(I) links hold the protein rings together. The cargo is sealed inside and protected in circulation.
- **Triggered** — Inside the cell, a reducing agent breaks the gold links. Nothing else about the cage has to change.
- **Released** — The cage falls apart and delivers its payload where it is needed — not on the way there.

## Two segments of focus

One platform, two therapeutic problems it is unusually well suited to.

### Synthetic VLP Vaccines

Stronger and more durable vaccines against respiratory disease, with antigens mounted on both the outside and the inside of the cage.

[Read the science](https://www.ncage.org/en/synthetic-vlp-vaccines)

### Antibody Drug Conjugates

A safer profile for blockbuster anti-cancer drugs, by holding the payload shut until the cage reaches the target cell.

[See delivery systems](https://www.ncage.org/en/drug-delivery-systems)

## Working on vaccines or targeted delivery?

We partner with pharmaceutical companies and research groups on programs where antigen density, payload protection or controlled release is the bottleneck.