Pivoting Cas9 to Cas12a: in vivo delivery of next-gen editors and tradeoffs

[ScarlettFA]

I'm a research scientist in a therapeutic development lab, and we're closely following the recent CRISPR gene editing advances, particularly the move towards more precise base and prime editing techniques that reduce off-target effects. Our team is evaluating whether to pivot our approach for a specific genetic disorder from traditional CRISPR-Cas9 to a newer editor like Cas12a for its different PAM requirements and potential efficiency in our target cells. For others working at this cutting edge, what are the most promising recent papers or pre-prints you've seen regarding in vivo delivery systems for these next-generation editors? How are you assessing the trade-offs between the increased precision of base editors and their current limitations in scope and size of editable sequences compared to the more established, but less accurate, knockout approaches?

[Justin.H]

Exciting area. At a high level, the big questions are how to deliver editors safely in vivo, and whether the precision gains of base/prime editors justify the current limits in target scope and delivery. A good starting point is to assemble a reading list that covers both the molecular engineering side and the delivery technologies.

[Sofia85]

Delivery remains the bottleneck. Base/primes editors are often too large for standard AAV; people are using dual-AAV split approaches or smaller Cas variants (e.g., SaCas9- or Cas12a-based platforms) to fit payloads. Non-viral routes like lipid nanoparticles carrying mRNA and gRNA are promising for particular tissues, but tropism and immune responses complicate translation. Virus-like particles (VLPs) are another avenue to reduce exposure time. In vivo assessments typically compare on-target editing efficiency, off-target profiles, and any immune or toxicities.

[JacobL]

For a literature starter, look for: foundational base-editing papers (ABE/CBE) and prime editing; the in vivo delivery papers that demonstrate editing in mouse models; and reviews on delivery strategies. Then check recent preprints that discuss Cas12a-enabled editors and expanded PAM compatibility. Keep an eye on papers about minimizing off-target effects (engineered deaminases, high-fidelity Cas variants) and on methods to quantify mosaicism in vivo. Because this field moves fast, set alerts on bioRxiv for terms like 'in vivo base editing' and 'prime editing delivery.'