Smart Delivery Tech increases CRISPR efficiency and restores mouse vision

Researchers from Helmholtz Munich and the Institute of Technology Munich have developed an advanced delivery system that transports gene editing tools to live cells more efficiently than before, based on the CRISPR/CAS9 gene editing system. Their technology, Envlpe, uses engineered non-infectious virus-like particles to accurately correct bad genes.

The system also retains the possibility of advancement in cancer treatment by allowing precise genetic manipulation of engineered immune cells, making it more universally compatible and therefore more accessible to a larger group of cancer patients.

This work has been featured in Journal Cell.

Overcoming the delivery challenges in gene editing

Modern genome editing technologies, including the CRISPR system, have great potential to treat genetic disorders. However, ensuring that these molecular tools are delivered to target cells remains an important challenge.

“Previous viral and non-viral delivery systems such as adeno-associated viruses (AAVS), lipid nanoparticles (LNPs), and other virus-like particles (VLPs) are valuable, but facial limitations are valuable.”

“The challenges include increased sustainability of gene editors that can trigger immune responses, or simply limited efficiency. Envlpe addresses these issues directly, but its modular design will remain compatible with future advances in gene editing.”

Envlpe is based on a modified non-infectious virus-derived shell. These act as carriers for molecular gene editors such as base editors and prime editors. This is a special CRISPR tool that allows you to chemically alter a single DNA base in the genome to remove or insert new DNA sequences. The Envlpe design solves the logistics challenges of previous methods during VLP production by hijacking the intracellular transport mechanism so that all components come together at the right time and place.

In many cases, previous methods included partially assembled nonfunctional gene editors, which reduced delivery efficacy.

“Envlpe not only guarantees a fully assembled package of gene editors, but also includes an extra molecular shield that protects the most vulnerable parts of the editor in transit from degradation,” explains Truong. “This allows for the safe delivery of genetic tools to the target cell, where the intended DNA editing is done.”

Vision Restoration: Working Gene Editing

Working closely with a team led by Professor Krzysztof Palczewski, an ophthalmology professor at UC Irvine, scientists tested the Evlpe system in a mouse model of hereditary blindness.

“Mice carry a disturbing mutation to the RPE65 gene, which is essential for generating photosensitive molecules in the retina, and therefore do not respond completely blindly to light,” explains co-authors and Samuel W. Du, MD/Ph.D. Candidate for UC Irvine.

After injecting Envlpe into the subretinal space (the area between the retinal pigment epithelium and the photoreceptor) to correct the mutation, the animals began to respond again to light stimuli.

“The degree of repair was incredible,” says Julian Geylencuzer, co-author of the study and a doctoral researcher at the Institute of Synthetic Biomedicine. “Our particles have shown that there is a real potential for treatment in living animals.”

Compared to established systems, Envlpe achieved significantly better results. Competing systems required more than 10 times more doses to achieve similar effects.

“Our goal was to build tools that are useful for researchers and suitable for practical applications,” said Niklas Armbrust, co-author of the Institute of Synthetic Biomedical Sciences and a doctoral researcher. “We solved important bottlenecks and achieved a more efficient package with delivery agents.”

Advances in cancer therapy with universal T cells

Envlpe can also open up new possibilities for adoptive T-cell therapy so that immune cells collected from patients are genetically modified in the lab, allowing them to specifically recognize and attack tumor cells.

In collaboration with Andrea Schmidts’ lab at Tum University Hospital, researchers using Envlpe promoted targeted removal of certain surface molecules that can trigger immune responses when cells are administered to recipients that are different from donors. This could lead to the development of so-called “universal” T cells that do not need to be customized for individual patients, making treatments more accessible and cost-effective.

These innovations address both the key challenges of in vivo gene therapy for genetic genetic diseases, provide ex vivo cell therapy for cancer, paving the way for important translational advances.

“The highly modular Envlpe system is virtually close to on-demand and accurate genetic modifications of complex cell models,” says Professor Gilwestmeyer, professor of Synthetic Biomedical Institute and Neurobiological Engineering at TUM and co-author of the study. “This is an example of how synthetic biology can help drive medical innovation.”

Move towards clinical use

Currently, the team that has achieved highly efficient delivery of the most common gene editing tools is looking to use the diversity found in nature along with recent advances in AI-assisted protein design to increase targeting accuracy by limiting the delivery of these tools to specific cell or tissue types.

To migrate Envlpe into clinical applications, the research team is pursuing follow-up funding from translation grants and partnerships in the pharmaceutical industry. The goal is to optimize technologies for a variety of therapeutic applications and ultimately make them available to patients.