For the first two decades of regenerative-medicine research the conversation was almost entirely about cells: which cell type to use, which source to draw it from, how to expand it in culture, how to deliver it into the body, and how to keep it alive once delivered. The shift to thinking about what cells secrete rather than the cells themselves was a long, quiet pivot that accumulated across roughly a decade of evidence before becoming a mainstream position.
Three reviews from the 2013 to 2014 period are useful landmarks. Yeo and colleagues in 2013 surveyed the musculoskeletal and immune literature and reached a clear conclusion: in most documented contexts, the cells were not doing the work directly. They were sending biological signals into the surrounding tissue, and those signals were the active material. Tan and colleagues in 2014 reached similar conclusions in cardiac contexts. Sinden and colleagues in the same year focused on neurological models and again found that paracrine activity, rather than cellular engraftment, explained most of the observed effects.
Beyond the review literature, the empirical case for cell-free preparation methods kept accumulating. Lopatina and colleagues had already shown in 2012 that microvesicle preparations isolated from cell cultures produced comparable biological effects to the whole-cell preparations from which they were derived. The Stem Cells International 2014 review consolidated much of this evidence and made the broader case that the field should reconsider its operational assumptions about cell-based therapy.
What this meant in practice was a shift in research agenda. If the active material was the secretome rather than the cell, the practical problems shifted with it. The work of generating, characterising, and delivering a reproducible biological preparation looks different from the work of expanding a cell line, maintaining its viability through transit, and engrafting it into a target tissue. Cell-free approaches inherited their own set of problems, including the question of how to standardise a complex biological mixture, but they shed the engraftment and viability problems that had complicated the cell-therapy field for two decades.
There were also operational implications. A cell-based therapy programme requires sterile transport of living cells, defined cold-chain logistics, and tight scheduling between the clinic, the processing facility, and the clinic again. A cell-free preparation programme can use a stable, characterised, non-cellular biological preparation that travels under less demanding conditions. None of this makes cell-free preparation methods easy. It makes them differently constrained.
By 2020 these threads had largely converged. The peer-reviewed literature on extracellular vesicles, exosomes, and secretome-derived preparations had grown from a niche topic to a substantial body of work spanning multiple therapeutic areas. Clinical-stage trials in cell-free approaches had begun appearing on registries. Regulatory agencies, including the United States Food and Drug Administration, had clarified their thinking on the autologous, minimally manipulated end of the space through guidance documents that informed how compliant programmes were structured.
Wellbeing’s research programme had been working on cell-free, autologous, secretome-led preparations since well before this convergence. The pivot in the wider field meant the conversation around the work became easier to have. What had previously been an unusual position became, increasingly, a mainstream one. Wellbeing’s own research focus narrowed and tightened through this period rather than expanded, reflecting a confidence that the underlying approach was correct and that the work to be done was deepening the rigour of preparation, characterisation, and delivery.
For readers who want to understand the science of why the field landed where it did, the three review papers referenced earlier in this piece are the right starting point. For readers who want to understand what this means for Wellbeing’s current programme specifically, the white-paper series being published through 2026 is the more direct reference. Paper 5 of the series, Quality Over Quantity, is the entry point that most readers find useful.
The pivot from cells to cell-free was not a single moment. It was a decade of accumulated evidence pointing in a consistent direction. By the time it had become the field’s mainstream working position, the work had already shifted to refining how to do cell-free preparation well.