#mesenchymal stem cells

An 'extra-large extracellular vesicle' (XLEV), far bigger than an exosome, is released from the region around the cell nucleus loaded with sonic hedgehog, the molecule that shapes the body. The work comes from the University of Tokyo. The surprise was that what pushed that release was the 'off' form of a protein called Rab18 — a logic that contrasts with conventional models, which have emphasized the GTP-bound form.

Rats had their spinal cords hemisected at two separated levels—the right side at T7 and the left side at T12—and received a single intravenous dose of bone-marrow-derived mesenchymal stem cells the day after injury. At 28 days the motor score was 12.2 versus 5.4. The nerve pathways drawn from nine hours of 7-tesla MRI on the excised cords had built a detour to the outside at the rostral lesion. At the caudal lesion, however, what stood out was not a lateral detour but a route crossing the midline to the opposite side. Dr. Exotaro reads a preclinical study.

An original research paper that ran human bone marrow–derived MSCs continuously in a hollow fiber bioreactor for about 40 days and kept harvesting the small extracellular vesicles (sEVs) that came out, four times a week. The paper reports that particle size, markers, and yield were stable (no numerical value for particle size appears in the main text), while mass spectrometry found 1,618 proteins differentially altered between Phase 3 and Phase 1. It is entirely a story from inside a culture device, and whether the later vesicles work was never measured once.

We read a review that promotes the "young" mesenchymal stem cells harvested from the umbilical cord jelly thrown away at every birth, along with their secreted products, as the trump card of post-stroke regenerative medicine. There are no new data, and no literature search procedure is written down. And among its 285 references, there was not a single clinical trial that gave stroke patients material explicitly identified as Wharton's jelly-derived.

A narrative review of knee injections, corticosteroids to exosomes: an RCT tying repeated triamcinolone to cartilage loss, and the evidence-maturity gap across PRP, orthobiologics, MSCs, exosomes.

MSC-derived extracellular vesicles are biocompatible, low-immunogenicity 'natural nanocapsules.' This review maps six strategies to engineer them into drug carriers and their clinical safety data.