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A Boost for the Precision of Genome Editing

The FDA’s recent approval of the first CRISPR-Cas9–based gene therapy has marked a major milestone in biomedicine, validating genome editing as a promising treatment strategy for disorders like sickle cell disease, muscular dystrophy, and certain cancers.

CRISPR-Cas9, often likened to “molecular scissors,” allows scientists to cut DNA at targeted sites to snip, repair, or replace genes. But despite its power, Cas9 poses a critical safety risk: the active enzyme can linger in cells and cause unintended DNA breaks—so-called off-target effects—which may trigger harmful mutations in healthy genes.

Now, researchers in the labs of Professor Ronald T. Raines (MIT Department of Chemistry) and Professor Amit Choudhary (Harvard Medical School) have engineered a precise way to turn Cas9 off after its job is done—significantly reducing off-target effects and improving the clinical safety of gene editing. Their findings are detailed in a new paper published this week in the Proceedings of the National Academy of Sciences (PNAS).


Researchers used cells that glow green due to a green fluorescent protein (GFP) gene. If Cas9 is working, it disrupts the GFP gene and the cells stop glowing. If LFN-Acr blocks Cas9, the cells keep glowing. These images depict cells in different conditions: some with active Cas9 (which stopped the green glow), some with Cas9 and LFN-Acr (glow stayed on).

Image courtesy of the researchers.

DNA nanostructures can mimic molecular organization of living systems without chemical cross-linking

Newly developed DNA nanostructures can form flexible, fluid, and stimuli-responsive condensates without relying on chemical cross-linking, report researchers from the Institute of Science Tokyo and Chuo University, in the journal JACS Au.

Owing to a rigid tetrahedral motif that binds the linkers in a specific direction, the resulting string-like structures form condensates with exceptional fluidity and stability. These findings pave the way for adaptive soft materials with potential applications in drug delivery, artificial organelles, and bioengineering platforms.

Within living cells, certain biomolecules can organize themselves into specialized compartments called biomolecular condensates. These droplet-like structures play crucial roles in cellular functions, such as regulating and ; they essentially represent nature’s clever way of organizing cellular activity without the need for rigid membranes.

CRISPR-GPT Turns Novice Scientists into Gene Editing Experts

CRISPR technology has revolutionized biology, largely because of its simplicity compared to previous gene editing techniques. However, it still takes weeks to learn, design, perform, and analyze CRISPR experiments; first-time CRISPR users often end up with low editing efficiencies and even experts can make costly mistakes.

In a new study, researchers from Stanford University, Princeton University, and the University of California, Berkeley, teamed up with Google DeepMind to create CRISPR-GPT, an artificial intelligence (AI) tool that can guide researchers through every aspect of CRISPR editing from start to finish in as little as one day.1 The results, published in Nature Biomedical Engineering, demonstrate that researchers with no previous CRISPR experience could achieve up to 90 percent efficiency in their first shot at gene editing using the tool.

CRISPR-GPT is a large language model (LLM), a type of AI model that uses text-based input data. Led by Le Cong of Stanford University and Mengdi Wang of Princeton University, the team trained the model on over a decade of expert discussions, as well as established protocols and peer-reviewed literature. They designed it to cover gene knockout, base editing, prime editing, and epigenetic editing systems, and benchmarked the tool against almost 300 test questions and answers.

First gene-edited islet transplant in a human passes functional trial

Uppsala University Hospital-led investigators report that gene-edited donor islet cells survived 12 weeks inside a man with long-standing type 1 diabetes without any immunosuppressive medication.

Intensive insulin therapy can delay complications and improve life expectancy. Early-onset type 1 diabetes remains linked to reduced quality of life, serious cardiovascular risk, and shortened lifespan. Toxicity from lifelong immune suppression also drives morbidity and mortality in organ recipients.

In the study, “Survival of Transplanted Allogeneic Beta Cells with No Immunosuppression,” published in the New England Journal of Medicine, researchers conducted a first-in-human open-label trial to test whether hypoimmune-engineered islet cells could evade rejection.

Chinese Scientists Unveil Major Breakthrough in Large-scale DNA Editing

Chinese scientists have developed a gene editing technology capable of precisely manipulating large DNA segments ranging from thousands to millions of base pairs in both plant and animal cells, marking a significant advance in the field of life sciences.

The research team from the Institute of Genetics and Developmental Biology at the Chinese Academy of Sciences announced the new technology in a study published online Monday in the journal Cell.

The method, called PCE (Programmable Chromosomal Engineering), combines three innovative techniques to enable programmable editing of large chromosome segments. In lab tests, researchers successfully inserted an 18,800-base-pair DNA fragment, replaced a 5,000-base-pair sequence, inverted a 12-million-base-pair chromosomal region, deleted a 4-million-base-pair segment, and even relocated entire chromosomes.

Scientists just cracked the code to editing entire chromosomes flawlessly

A group of Chinese scientists has created powerful new tools that allow them to edit large chunks of DNA with incredible accuracy—and without leaving any trace. Using a mix of advanced protein design, AI, and clever genetic tweaks, they’ve overcome major limitations in older gene editing methods. These tools can flip, remove, or insert massive pieces of genetic code in both plants and animals. To prove it works, they engineered rice that’s resistant to herbicides by flipping a huge section of its DNA—something that was nearly impossible before.

Rationale engineering generates a compact new tool for gene therapy

Scientists at the McGovern Institute for Brain Research at MIT and the Broad Institute of MIT and Harvard have re-engineered a compact RNA-guided enzyme they found in bacteria into an efficient, programmable editor of human DNA.

The protein they created, called NovaIscB, can be adapted to make precise changes to the genetic code, modulate the activity of specific genes, or carry out other editing tasks. Because its small size simplifies delivery to cells, NovaIscB’s developers say it is a promising candidate for developing gene therapies to treat or prevent disease.

The study was led by Feng Zhang, the James and Patricia Poitras Professor of Neuroscience at MIT who is also an investigator at the McGovern Institute and the Howard Hughes Medical Institute, and a core member of the Broad Institute. Zhang and his team reported their open-access work this month in the journal Nature Biotechnology.


Researchers at MIT and the Broad Institute, led by Professor Feng Zhang, redesign a compact RNA-guided enzyme from bacteria, making it an efficient editor of human DNA.

Humanlike “teeth” have been grown in mini pigs

Lose an adult tooth, and you’re left with limited options that typically involve titanium implants or plastic dentures. But scientists are working on an alternative: lab-grown human teeth that could one day replace damaged ones.

Pamela Yelick and Weibo Zhang at Tufts University School of Dental Medicine in Boston have grown a mixture of pig and human tooth cells in pieces of pig teeth to create bioengineered structures that resemble real human teeth.


The toothlike structures represent a step toward bioengineered replacements for dental implants, say researchers behind the work.

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