Lab-grown blood for routine transfusions

How far are we from using lab-grown red blood cells for routine transfusions?

Red blood cells have been grown from stem cells in the laboratory, and by November 2022 two people in the UK RESTORE trial had each received a very small transfusion of lab-grown cells. A 2025 lab study reports about 4,600 red cells per stem cell, but a single unit of donated blood holds about 2 × 10^12 red cells, and that scale has not been tested. No results yet show how long lab-grown cells last in the body, so routine transfusion is not close.

AI illustration · Illustrative scene, not a photograph of the specific device or experiment.
WHERE WE AREEngineering prototypes

Getting closer. Prototypes exist, but not in real-world use.

Red cells have been made from stem cells at laboratory scale, and a small number of people have received minitransfusions of lab-grown cells. Production in bioreactors at the scale of one transfusion unit has not been shown, and no survival or safety results have been published, so the stage is engineering prototype rather than pilot.

The tech tree

Everything recorded on Vrulum that this future needs, oldest foundations at the top and the goal at the bottom. Lines show what each step requires.

What it takes: Lab-grown blood for routine transfusions Unlocked Being researched Locked
  1. 2021Lab-grown red blood cellsResearch and prototypes Being researched.
  1. 2022First human transfusions of lab-grown red cellsDone Unlocked.
  2. 2023Lab-grown platelets given to people in JapanDone Unlocked.
  3. 2025Red cells made from stem cells in the laboratoryDone Unlocked.
  4. 2025Lab-scale yield of about 4,600 red cells per stem cellDone Unlocked.
  5. Date not recordedControlled trial comparing lab-grown and donor cell survivalIn progress Being researched.
  6. Date not recordedPublished survival and safety results from the RESTORE trialNot started Locked.
  7. Date not recordedProduction in stirred-tank bioreactorsNot started Locked.
  8. Date not recordedProduction at the scale of one blood unitNot started Locked.
  9. Date not recordedRoutine clinical use for transfusionNot started Locked.
  1. GoalLab-grown blood for routine transfusionsGoalRequires: Lab-grown red blood cells, Red cells made from stem cells in the laboratory, Lab-scale yield of about 4,600 red cells per stem cell, First human transfusions of lab-grown red cells, Lab-grown platelets given to people in Japan, Controlled trial comparing lab-grown and donor cell survival, Published survival and safety results from the RESTORE trial, Production in stirred-tank bioreactors, Production at the scale of one blood unit, Routine clinical use for transfusion. Locked.

The road so far

4 of 9 steps done, 1 in progress.

  1. Done · 12 Jul 2025Red cells made from stem cells in the laboratory

    Researchers have grown red cells from induced pluripotent stem cells in lab culture, including enucleation, the step in which the cell ejects its nucleus. Ju and colleagues (2024) cite enucleation rates of 4 to 10% for hiPSCs, from earlier work by Lapillonne and colleagues (2010). Varga and colleagues (2025) report a consistent 40 to 70% enucleation rate in their optimised system. [3][5]

  2. Done · 12 Jul 2025Lab-scale yield of about 4,600 red cells per stem cell

    Varga and colleagues report about 4.6 × 10^3 red cells per iPSC in an optimised, feeder-free dynamic culture. Stirred-tank bioreactors were not tested, and the authors list them as future work. [3]

  3. Done · 7 Nov 2022First human transfusions of lab-grown red cells

    The RESTORE trial, a joint initiative of NHS Blood and Transplant and the University of Bristol, had given mini transfusions to two people by 7 November 2022. The lab-grown dose was about 5 to 10 ml. The trial team reported that both were well and that no untoward side effects were reported. No formal safety results were found in the sources reviewed. [1][2]

  4. Done · 10 Jan 2023Lab-grown platelets given to people in Japan

    The Japanese MEG-002 study (Megakaryon) gave three units of iPSC-derived platelets to one enrolled person. The study was marked complete on 10 January 2023, against a target sample size of 10. The registry reports a transient rise in platelet counts and no adverse events. The study used platelets, not red cells, and one person is not enough to show safety or benefit. [6]

  5. In progressControlled trial comparing lab-grown and donor cell survival

    RESTORE gives each volunteer two mini transfusions at least four months apart, one of lab-grown cells and one of standard red cells from the same donor. The trial examines how long each lasts in the body. The trial is planned for at least 10 participants. The sources reviewed do not report how many have completed both transfusions or any survival results. [1][2]

  6. Not startedPublished survival and safety results from the RESTORE trial

    No survival or formal safety results from RESTORE have been published in the sources reviewed. [1]

  7. Not startedProduction in stirred-tank bioreactors

    Varga and colleagues describe stirred-tank bioreactors as future work and expect them to reduce variation in production efficiency. They report no bioreactor data. [3]

  8. Not startedProduction at the scale of one blood unit

    A single unit of blood contains about 2 × 10^12 enucleated red cells (Lim and colleagues, 2021). Varga and colleagues estimate that about 4.9 × 10^7 iPSCs would be needed for one minitransfusion unit of about 1 × 10^11 enucleated cells, a much smaller dose. No one has shown production at the scale of a full transfusion unit. [4][3]

  9. Not startedRoutine clinical use for transfusion

    The trial team says that, for the foreseeable future, manufactured cells could only be used for a very small number of patients with very complex transfusion needs. Donated blood will still be needed. No date for routine use is given. [2]

Why it matters

Donated blood is the only source of red cells for transfusion. Some patients with complex transfusion needs can be hard to match with donor blood, and the RESTORE trial team says manufactured cells could, for the foreseeable future, only be used for a very small number of such patients. Lab-grown cells could one day add a supply that does not depend on donors, but only if they can be made in large amounts, at a cost the health service can pay, and with proven safety.

What stands in the way

  • Yield: lab-scale work gives about 4.6 × 10^3 red cells per stem cell, and one minitransfusion unit needs an estimated 4.9 × 10^7 iPSCs (Varga and colleagues, 2025). A full unit of about 2 × 10^12 enucleated cells needs far more.
  • Scale-up: the lab-scale process runs in dynamic culture, and stirred-tank bioreactors have not been tested for this process.
  • Cost: a 2021 review reports that most in vitro production processes conclude a blood unit could cost US$15,000 or more, and notes that some estimates are five times higher. These are estimates from the literature, not a measured cost.
  • Clinical-grade manufacture: Lim and colleagues (2021) state that fully defined, xenogeneic-free processes are an inescapable requirement for clinical translation, and that GMP must be observed. Varga and colleagues describe their system as xeno-free and GMP-compatible, but this has not been checked independently.
  • Survival and safety in people: RESTORE is a first-in-human trial of at least 10 participants. No survival results have been published, so it is not yet known whether lab-grown cells last as long as donor cells.

Signals to watch

  • Publication of RESTORE results comparing how long lab-grown and donor red cells survive in the body.
  • Formal safety reporting from the RESTORE trial in a peer-reviewed paper or an official NHS Blood and Transplant report.
  • Bioreactor data for the iPSC red cell process at larger volumes, which the Varga authors list as future work.
  • Independent repeats of the 40 to 70% enucleation rate in other laboratories.
  • Results from further platelet studies, such as the Japanese MEG-002 study, which the registry lists as completed with one participant.

Sources

  1. university press release
    First ever clinical trial of lab-grown red blood cell transfusion
    University of Cambridge, 7 Nov 2022.
  2. university press release
    First ever clinical trial of laboratory grown red blood cells being transfused into another person underway
    University of Bristol, 7 Nov 2022.
  3. peer reviewed paper
    Large-Scale Production of Transfusion-Ready Red Blood Cells From Induced Pluripotent Stem Cells
    Eszter Varga, Eelke Brandsma, Brenda E. Juarez-Garza et al.. Advanced Science, 12 Jul 2025.
  4. review article
    Industrially Compatible Transfusable iPSC-Derived RBCs: Progress, Challenges and Prospective Solutions
    Zhong Ri Lim, Svetlan Vassilev, Yew Wai Leong et al.. International Journal of Molecular Sciences, 10 Sept 2021.
  5. review article
    Progresses in overcoming the limitations of in vitro erythropoiesis using human induced pluripotent stem cells
    Hyeonwoo Ju, Yeowon Sohn, Yoojun Nam et al.. Stem Cell Research & Therapy, 15 May 2024.
  6. dataset
    Exploratory clinical study on the tolerability, safety and efficacy of iPS cell-derived platelets (MEG-002) in patients with thrombocytopenia (jRCT2053210068)
    Japan Registry of Clinical Trials (jRCT), 10 Jan 2024.

Last reviewed 21 Oct 2026.