Cellular Replacement
Transplantation established that functional cells could restore biological systems damaged by disease, radiation or treatment.
History of Regenerative Medicine
From bone-marrow transplantation to cellular reprogramming.
Modern regenerative medicine developed through decades of work in transplantation, stem-cell biology, tissue culture, extracellular-vesicle research, molecular signalling and cellular reprogramming. Its progress reflects the work of many independent laboratories rather than a single physician, clinic or institution.
Historical Overview
A field built through connected scientific discoveries
Regenerative medicine did not begin with a single commercial therapy. It developed from several scientific traditions, including transplantation medicine, haematology, developmental biology, tissue engineering, cell culture and molecular signalling.
Bone-marrow transplantation provided the earliest practical demonstration that living cells could restore a damaged physiological system.
Later work identified distinct stem and progenitor populations, including haematopoietic stem cells and bone-marrow stromal precursors.
The discovery of extracellular vesicles and cell-secreted signalling factors broadened the field beyond the concept that transplanted cells must permanently engraft or directly replace damaged tissue.
Induced pluripotent stem-cell technology later demonstrated that mature somatic cells could be experimentally reprogrammed to a pluripotent state.
Scientific Foundations
Three foundations of regenerative medicine
Endogenous Repair
Stem- and progenitor-cell research demonstrated that tissues contain populations capable of self-renewal, differentiation and repair.
Cellular Signalling
Secretome, growth-factor and extracellular-vesicle research showed that cells may influence repair through released biological signals as well as through direct tissue integration.
Chronological Timeline
Principal milestones in regenerative medicine
The dates below represent major published scientific and clinical milestones. They should not be interpreted as the sole origin of each field, because related research often developed simultaneously in several laboratories.
1957
Clinical Transplantation
Early intravenous bone-marrow infusion in human patients
E. Donnall Thomas, H. L. Lochte Jr., W. C. Lu and J. W. Ferrebee
Mary Imogene Bassett Hospital, Cooperstown, New York, United States
Thomas and colleagues published an early clinical report describing intravenous bone-marrow infusion in patients receiving radiation and chemotherapy.
These early studies helped establish the clinical foundation for modern bone-marrow and haematopoietic stem-cell transplantation.
View the indexed publication →
1960–1961
Haematopoietic Stem Cells
Quantitative demonstration of bone-marrow colony-forming cells
Ernest A. McCulloch and James E. Till
Ontario Cancer Institute and University of Toronto, Canada
Till and McCulloch developed quantitative methods for studying the survival and colony-forming capacity of normal mouse bone-marrow cells.
Their work became foundational to the experimental concept of haematopoietic stem cells and clonal self-renewal.
View the 1961 publication →
1968
Bone-Marrow Stromal Precursors
Identification of osteogenic stromal precursor activity
Alexander J. Friedenstein, K. V. Petrakova, A. I. Kurolesova and G. P. Frolova
USSR Academy of Medical Sciences, Moscow
Friedenstein and colleagues described precursor cells associated with osteogenic and haematopoietic tissue formation in heterotopic bone-marrow transplantation experiments.
This work is widely regarded as one of the foundational publications in the history of bone-marrow stromal and mesenchymal-cell biology.
View the 1968 publication →
1970
Colony-Forming Fibroblasts
Development of fibroblast colonies from bone marrow
Alexander J. Friedenstein, R. K. Chailakhjan and K. S. Lalykina
Moscow-based Soviet research laboratories
The investigators documented fibroblast-like colony formation in monolayer cultures of bone-marrow and spleen cells.
These colony-forming fibroblastic precursors later became closely associated with the CFU-F concept used in stromal-cell research.
View the 1970 publication →
1983
Extracellular Vesicle Observation
Vesicular release during reticulocyte maturation
Bin-Tao Pan and Rose M. Johnstone
McGill University, Montreal, Canada
Pan and Johnstone observed the release of transferrin-receptor-containing vesicles during the in-vitro maturation of sheep reticulocytes.
These experiments formed part of the work that led to the recognition of exosome release during reticulocyte maturation.
View the 1983 publication →
1987
Exosome Terminology
The term “exosomes” appears in the reticulocyte literature
Rose M. Johnstone, Margaret Adam, J. R. Hammond, Lloyd Orr and Catherine Turbide
McGill University, Montreal, Canada
Johnstone and colleagues described vesicle formation during reticulocyte maturation and used the term “exosomes” for the released vesicles.
At the time, their principal recognised function was the disposal of membrane components that were no longer required by maturing red blood cells.
View the 1987 publication →
1991
MSC Terminology
“Mesenchymal stem cells” formally enter the scientific literature
Arnold I. Caplan
Case Western Reserve University, Cleveland, Ohio, United States
Caplan proposed the term “mesenchymal stem cells” for culture-expandable cells considered capable of forming multiple mesenchymal tissues.
The paper strongly influenced the terminology, biological model and later commercial development of MSC-based technologies.
View the 1991 publication →
1995
Early Human MSC Trial
Phase I infusion of culture-expanded human marrow stromal progenitors
Hillard M. Lazarus, Stephen E. Haynesworth, Stanton L. Gerson, Nathan S. Rosenthal and Arnold I. Caplan
Ireland Cancer Center, University Hospitals of Cleveland and Case Western Reserve University, United States
The investigators reported the collection, ex-vivo culture expansion and intravenous infusion of autologous human bone-marrow-derived stromal progenitor cells.
The phase I study was designed principally to evaluate feasibility and infusion safety rather than clinical efficacy.
View the 1995 clinical publication →
2006
Induced Pluripotent Stem Cells
Mouse somatic cells reprogrammed to pluripotency
Kazutoshi Takahashi and Shinya Yamanaka
Kyoto University, Kyoto, Japan
Takahashi and Yamanaka demonstrated that mouse embryonic and adult fibroblasts could be reprogrammed into induced pluripotent stem cells by introducing four defined transcription factors: Oct3/4, Sox2, Klf4 and c-Myc.
This discovery established a new route to pluripotency without directly deriving the cells from an embryo.
View the original Cell publication →
2007
Human iPS Cells
Human adult fibroblasts reprogrammed to pluripotency
Kazutoshi Takahashi, Koji Tanabe, Mari Ohnuki, Megumi Narita, Tomoko Ichisaka, Kiichiro Tomoda and Shinya Yamanaka
Kyoto University, Kyoto, Japan
The Kyoto University team generated induced pluripotent stem cells from adult human dermal fibroblasts using defined transcription factors.
The achievement accelerated research in disease modelling, developmental biology, drug discovery and regenerative medicine.
View the original human iPSC publication →
2007
Exosomal RNA Communication
Exosomes shown to transfer functional RNA between cells
Hadi Valadi, Karin Ekström, Apostolos Bossios, Margareta Sjöstrand, James J. Lee and Jan O. Lötvall
University of Gothenburg, Gothenburg, Sweden
Valadi and colleagues demonstrated that exosomes contain messenger RNA and microRNA that can be transferred to recipient cells.
The study helped transform the interpretation of exosomes from cellular disposal particles into biologically active mediators of intercellular communication.
View the 2007 publication →
2011–2014
EV Standardisation
International organisation and reporting standards emerge
International extracellular-vesicle research community
International Society for Extracellular Vesicles
The formation of an international professional society and the later publication of Minimal Information for Studies of Extracellular Vesicles recommendations helped formalise terminology, isolation, characterisation and reporting expectations.
These efforts were necessary because vesicle preparations may contain mixed populations and non-vesicular contaminants.
Visit the International Society for Extracellular Vesicles →
2012
Nobel Recognition
Cellular reprogramming recognised by the Nobel Committee
Sir John B. Gurdon and Shinya Yamanaka
University of Cambridge and Kyoto University
Gurdon and Yamanaka received the Nobel Prize in Physiology or Medicine for the discovery that mature cells can be reprogrammed to become pluripotent.
The award connected earlier nuclear-reprogramming experiments with the development of induced pluripotent stem-cell technology.
Review the Nobel scientific background →
2017
MSC Concept Reassessment
Caplan proposes reconsidering the meaning of “MSC”
Arnold I. Caplan
Case Western Reserve University, Cleveland, Ohio, United States
Caplan argued that the term “mesenchymal stem cell” was frequently misunderstood and proposed “medicinal signalling cells” as a functional interpretation.
The proposal emphasised immunomodulatory and trophic signalling rather than assuming direct replacement of damaged tissue through differentiation.
View the 2017 publication →
2023
Modern EV Guidance
MISEV2023 updates extracellular-vesicle research guidance
International Society for Extracellular Vesicles contributors
International scientific consortium
MISEV2023 updated international recommendations concerning extracellular-vesicle nomenclature, collection, separation, characterisation, functional studies and reporting.
The guidance reflects the continuing need to distinguish demonstrated product identity from broad or unsupported use of the term “exosome.”
Review MISEV2023 →
Principal Pioneers
Scientists and physicians who shaped the field
The following individuals represent key milestones, but the development of regenerative medicine involved many additional collaborators, research teams and institutions.
E. Donnall Thomas
Physician and transplantation researcher
Conducted pioneering clinical work that helped establish bone-marrow transplantation as a therapeutic discipline.
James E. Till and Ernest A. McCulloch
Ontario Cancer Institute and University of Toronto
Developed quantitative clonal assays that became foundational to experimental stem-cell biology.
Alexander J. Friedenstein
USSR Academy of Medical Sciences
Identified colony-forming fibroblastic and osteogenic precursor activity in bone-marrow stromal populations.
Arnold I. Caplan
Case Western Reserve University
Popularised the mesenchymal stem-cell concept and later argued for greater emphasis on the cells' signalling functions.
Hillard M. Lazarus and Collaborators
University Hospitals of Cleveland and Case Western Reserve University
Reported an early phase I study involving culture-expanded and intravenously infused human marrow stromal progenitor cells.
Rose M. Johnstone and Collaborators
McGill University
Characterised vesicular release during reticulocyte maturation and helped establish the term exosome.
Hadi Valadi, Jan O. Lötvall and Collaborators
University of Gothenburg
Demonstrated that exosomes contain transferable messenger RNA and microRNA capable of functioning in recipient cells.
Shinya Yamanaka and Kazutoshi Takahashi
Kyoto University
Reprogrammed differentiated somatic cells into induced pluripotent stem cells using defined transcription factors.
Sir John B. Gurdon
University of Cambridge
Earlier nuclear-transfer experiments established that differentiated-cell nuclei retain the genetic information required to direct development.
Historical Interpretation
Scientific discovery is not the same as clinical validation
Important qualification
The date on which a biological phenomenon was first described is not necessarily the date on which it became a safe, effective or approved treatment.
Bone-marrow transplantation required extensive clinical development before it became established for defined indications. MSCs, extracellular vesicles, secretome products and iPSC-derived therapies have followed different and generally more complex translational pathways.
Many proposed applications remain investigational. Historical importance should not be used as a substitute for product-specific manufacturing, safety, clinical and regulatory evidence.
Primary and Foundational References
Scientific sources supporting this timeline
Thomas ED, Lochte HL Jr, Lu WC, Ferrebee JW. Intravenous infusion of bone marrow in patients receiving radiation and chemotherapy. New England Journal of Medicine. 1957;257:491–496. PubMed
Till JE, McCulloch EA. A direct measurement of the radiation sensitivity of normal mouse bone marrow cells. Radiation Research. 1961;14:213–222. PubMed
Friedenstein AJ, Petrakova KV, Kurolesova AI, Frolova GP. Heterotopic of bone marrow. Analysis of precursor cells for osteogenic and haematopoietic tissues. Transplantation. 1968;6:230–247. PubMed
Friedenstein AJ, Chailakhjan RK, Lalykina KS. The development of fibroblast colonies in monolayer cultures of guinea-pig bone marrow and spleen cells. Cell and Tissue Kinetics. 1970. PubMed
Pan BT, Johnstone RM. Fate of the transferrin receptor during maturation of sheep reticulocytes in vitro. Cell. 1983. PubMed
Johnstone RM, Adam M, Hammond JR, Orr L, Turbide C. Vesicle formation during reticulocyte maturation. Association of plasma membrane activities with released vesicles (exosomes). Journal of Biological Chemistry. 1987;262:9412–9420. PubMed
Caplan AI. Mesenchymal stem cells. Journal of Orthopaedic Research. 1991;9:641–650. PubMed
Lazarus HM, Haynesworth SE, Gerson SL, Rosenthal NS, Caplan AI. Ex vivo expansion and subsequent infusion of human bone marrow-derived stromal progenitor cells. Bone Marrow Transplantation. 1995;16:557–564. PubMed
Takahashi K, Yamanaka S. Induction of pluripotent stem cells from mouse embryonic and adult fibroblast cultures by defined factors. Cell. 2006;126:663–676. Journal
Takahashi K, Tanabe K, Ohnuki M, Narita M, Ichisaka T, Tomoda K, Yamanaka S. Induction of pluripotent stem cells from adult human fibroblasts by defined factors. Cell. 2007;131:861–872. Journal
Valadi H, Ekström K, Bossios A, Sjöstrand M, Lee JJ, Lötvall JO. Exosome-mediated transfer of mRNAs and microRNAs is a novel mechanism of genetic exchange between cells. Nature Cell Biology. 2007;9:654–659. PubMed
Caplan AI. Mesenchymal stem cells: Time to change the name! Stem Cells Translational Medicine. 2017;6:1445–1451. PubMed
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From scientific history to present-day technology
Explore how these historical discoveries now inform CELLMEX research, laboratory work and technology development.