News from Science China Press

Even a local mRNA injection can produce unwanted expression in the liver. Researchers have redesigned the lipid nanoparticles that carry mRNA to reduce this spillover in mice while preserving expression in injected muscle. The formulation also supports repeated dosing and improves the confinement of expression after local brain and eye delivery.

Umbilical cord blood is more than a source of stem cells for transplantation. A review in Science China Life Sciences examines how its diverse cells and bioactive components are being explored for cancer immunotherapy, inherited disorders and tissue repair. The authors connect these opportunities with advances in cell expansion, gene engineering and manufacturing, while identifying barriers to clinical translation. They emphasize that many emerging applications still require further evidence of safety, effectiveness and durable benefit.

A recent study published in National Science Review has revealed silicate magma can store far more oxygen than its chemically allows. In high-pressure experiments, silicate melt can store up to about 5 wt.% excess oxygen, which is released as the magma rising. The findings suggest that oxygen-rich magmas could carry oxidizing power from Earth’s interior toward the surface, and may explain links between large-scale magmatism episodes and atmospheric oxidation in Earth’s history.

Immune maturation after weaning has long been considered a one-time developmental milestone. By profiling 120,649 immune cells from 10 tissues of germ-free and microbiota-colonized mice from weaning to adulthood, researchers show that microbial signals are needed continuously: they maintain antigen-processing capacity in myeloid cells and relieve PDCD4-mediated translational repression in lymphocytes. Restoring the microbiota reversed the immune suppression, indicating that immune competence is a maintained state rather than a fixed endpoint.

A nationwide ChinaHEART cohort of 4,258,033 adults found that no single obesity measure provided consistently strong discrimination across all major chronic diseases. Relatively higher discrimination was observed for the Chinese visceral adiposity index (CVAI) in cardiovascular disease, the triglyceride-glucose index (TyG) in diabetes, and the a body shape index (ABSI) in COPD, while discrimination for cancer was generally limited. All measures showed limited discrimination for cancer, supporting disease- and population-specific risk assessment beyond BMI.

The tumor-confined nano-activator (iCLAN_TSP-SAg) can drive localized expression of bacterial superantigens within tumors, enabling potent, antigen-independent T-cell activation while avoiding systemic toxicity.

Scientists have developed a simple yet powerful strategy to overcome a long-standing challenge in cancer phototheranostics—the trade-off between imaging brightness, therapeutic efficacy, and biological stability. By systematically replacing hydrogen atoms with deuterium (a heavier isotope) in a near-infrared fluorescent molecule, researchers achieved simultaneous improvements in all three critical properties. The optimized nanoparticles delivered 26% higher fluorescence brightness, 14% more reactive oxygen species for killing cancer cells, and 20% better stability in blood. In mouse models, a single treatment completely eliminated breast tumors, and fluorescence-guided surgery enabled precise removal of colorectal cancer remnants that were invisible under white light—extending survival from under 20 days to over 60 days. The strategy is broadly applicable and does not require redesigning the molecular backbone, offering a versatile platform for next-generation cancer theranostics.