Technologies

New tools for human gene editing are rapidly advancing all sectors of biomedicine from basic biology to somatic gene therapy in the clinic. Precise editing of DNA sequences in the human genome can be used to correct mutations or introduce novel genetic functionality for many biomedical purposes. Currently, nonviral delivery of preformed CRISPR ribonucleoproteins (RNPs) is being developed for somatic gene editing applications.

Writing specific DNA sequences into the human genome is challenging with nonviral gene-editing reagents, since most of the edited sequences contain various imprecise insertions or deletions. Faithful writing of DNA – or scarless gene editing – within human cells remains an outstanding challenge, and improved strategies are sought. UW–Madison researchers have developed a modular RNA aptamer-streptavidin strategy, termed S1mplex, to ‘sharpen the scalpels’ used in genome surgery. In the new approach, CRISPR-Cas9 RNPs are complexed with a nucleic acid donor template, as well as other biotinylated molecules (e.g., quantum dots).

In human pluripotent stem cells, tailored S1mplexes increased the ratio of precisely edited to imprecisely edited alleles up to 18-fold higher than standard gene editing methods, and enriched cell populations containing multiplexed precise edits up to 42-fold.

These advances with versatile, preassembled reagents could greatly reduce the time and cost ofin vitro/ex vivogene editing applications in precision medicine and drug discovery, and aid in the development of increased and multiple dosing regimens for somatic gene editingin vivo.

The Wisconsin Alumni Research Foundation (WARF) is seeking commercial partners interested in advancing precision gene editing using modular CRISPR ribonucleoprotein complexes.

This highly novel approach has the potential to generate off-the-shelf, preassembled reagents customizable for any patient.