Protocols by Charles Sieg

The research frontier

Research frontier: organ replacement

Pig organ transplants, lab-grown and bioprinted tissue, organ preservation, and transplant tolerance without lifelong drugs, with the real numbers and where each stands as of November 2026.

Overall evidence Early26 sourcesReviewed November 5, 2026

Pig-organ results are single patients or brain-dead recipients, tolerance studies have 5 to 10 patients each, and only organ preservation has randomized trials behind it; the one approved lab-grown product here is a blood vessel.

The short version

  • Pig kidneys have worked in living people for as long as 271 days. In every case here the pig kidney was eventually removed or the patient died, so they are a bridge, not yet a replacement1,2,3.
  • The first pig heart (2022) worked until day 49, and life support was withdrawn on day 60. Pig livers and lungs have mostly been tested in brain-dead recipients; in the one living liver case here, the pig liver was removed on day 38 and the patient died on day 1714,5,6,7.
  • The strongest evidence is for keeping donor organs alive outside the body. In randomized trials, warm machine perfusion cut liver graft injury by 50%, and hearts from circulatory-death donors preserved by perfusion outside the body had 6-month survival similar to standard hearts8,9.
  • Transplant tolerance, living without anti-rejection drugs, has worked in a handful of kidney patients given donor bone marrow or stem cells, some off drugs for up to 11.4 years, but it takes heavy conditioning and does not always last10,11.
  • Bioprinting a solid organ is not a clinical technology. The one lab-grown product on this page with FDA approval is a blood vessel, not an organ12,13.

What "cure" means here

Replacing a failing organ is treatment, not cure of the underlying disease. I grade each item by what it has actually delivered: a graft that works, how long, and whether the patient still needs lifelong immunosuppressive drugs. A single patient or a brain-dead recipient is Early. Everything is dated "as of November 2026."

What the research says

Pig kidneys

Early Massachusetts General Hospital, January 25, 2025. A patient with end-stage kidney disease, facing a long wait for a deceased-donor kidney and with no suitable living donor, received a gene-edited pig kidney from eGenesis (EGEN-2784: major glycan antigens deleted, pig retroviruses inactivated, seven human genes added). It worked immediately and kept the patient off dialysis for 271 days. A T-cell rejection found on day 14 resolved with treatment. Function held for about 6 months, until immunosuppression was reduced during a bacterial infection; inflammation and thrombotic microangiopathy followed, and the graft failed and was removed. Eighty-two days later the patient received a human kidney that worked immediately, with no sign of sensitization over 231 days of follow-up, and no pig pathogen transmission was detected. This was the first recipient in a planned three-patient study under FDA expanded access, funded by the hospital and eGenesis1.

A separate study profiled the immune response in a different recipient of the same EGEN-2784 kidney, a 62-year-old man who died of a cardiac event on day 51. His early T-cell rejection reversed with stronger immunosuppression, after which T-cell immunity stayed suppressed but innate immune activity persisted; the authors say anti-rejection regimens need to target innate as well as adaptive immunity3.

Early NYU Langone Health. A news report says Towana Looney, 53, of Alabama, had her gene-edited pig kidney removed on April 4, 2025, after 130 days, when her body began to reject it. Her surgeon, Robert Montgomery, pointed to an earlier infection, slightly lowered anti-rejection drugs, and an immune system that was reactivating; she went back on dialysis2. I found no peer-reviewed paper on her case, so this rests on a news report.

Honest read: 130 and 271 days are single patients, and both pig kidneys were lost. The result that matters most is that the 271-day patient then received a human kidney without trouble, so a pig kidney can serve as a bridge1,2.

The formal trials (as of November 2026)

The FDA go-aheads were reported in early February 2025. United Therapeutics' trial of a 10-gene-edited kidney (UKidney) starts with six patients and expands to 50, for adults aged 55 to 70 who have been on dialysis for at least six months; eGenesis's study was described as three patients under an FDA expanded access protocol14. A 2025 editorial describes the United Therapeutics study (EXPAND, NCT06878560) as an open-label, single-arm phase 1/2/3 trial with 24-week primary endpoints, NYU Langone first, and says the first transplant took place in November 202515.

What I could not confirm: any efficacy results from either formal trial, and a primary-source FDA or sponsor page for the clearances. The two sources above are a patient-organization blog and an editorial, so ClinicalTrials.gov and the sponsors are the places to confirm the details.

Pig hearts, livers, and lungs

Early Heart. In the 2022 report, a 57-year-old man with nonischemic cardiomyopathy who depended on ECMO received a heart from a pig with 10 gene edits. He came off ECMO and the graft worked normally until day 49, when it suddenly thickened and failed; life support was withdrawn on day 60. The autopsy findings were not consistent with typical rejection4. This page covers only the peer-reviewed heart case I could open.

Early Liver. In a brain-dead recipient, a six-gene-edited pig liver, added as an auxiliary graft, made bile (66.5 mL by day 10), raised porcine albumin, and showed no signs of rejection on tissue analysis over 10 days5. In a living patient with a large liver cancer, a 10-edit pig liver was placed as an auxiliary graft and worked metabolically, but it was removed on day 38 because of xenotransplant-associated thrombotic microangiopathy, and the patient died on day 171 after repeated upper gastrointestinal bleeding. The authors call it feasible as a bridge to a human liver and call thrombotic microangiopathy a significant challenge to long-term success6.

Early Lung. A six-gene-edited pig lung in a 39-year-old brain-dead man stayed viable and working for the 216 hours of monitoring, with no hyperacute rejection or infection, but it developed severe edema at 24 hours, and antibody-mediated rejection appeared to damage it on days 3 and 6, with partial recovery by day 97.

Keeping donor organs alive outside the body

This is where the evidence is strongest, because it is randomized.

Moderate Normothermic machine perfusion of livers. In a randomized trial of 220 liver transplants, warm perfusion versus cold storage cut graft injury (measured by liver enzyme release) by 50% and organ discard by 50%, and allowed a 54% longer mean preservation time; bile duct complications, graft survival, and patient survival did not differ significantly8. It makes more organs usable and gives surgeons time. It has not been shown to extend life.

Moderate Hearts from circulatory-death donors. In a randomized noninferiority trial, 180 patients were transplanted: 90 with hearts from circulatory-death donors restarted and assessed by perfusion outside the body, and 90 with standard brain-death donor hearts kept in cold storage. In the 166 patients in the main analysis, risk-adjusted 6-month survival was 94% versus 90%, which met the trial's noninferiority margin of 20 percentage points, a wide one. TransMedics, which makes the perfusion device, funded the trial9. Six-month data from one industry-funded trial is the limit of what this shows.

Transplant tolerance without lifelong drugs

Early The idea is to give the recipient part of the donor's immune system so the new organ is seen as self. It works in a minority, with heavy conditioning.

  • In 2008, a Massachusetts General Hospital team reported five patients who got a kidney plus donor bone marrow after nonmyeloablative conditioning. One had irreversible rejection, and in the other four all immunosuppression was stopped at 9 to 14 months, with stable kidney function for 2.0 to 5.3 years16.
  • By 2014 the same team reported 10 patients. Seven stopped drugs for 4 or more years, four stayed off for 4.5 to 11.4 years, three went back on after 5 to 8 years, and 3 of the 10 kidneys failed10.
  • A separate approach used a bioengineered stem-cell graft: of 8 patients, 5 were weaned off all drugs at 1 year and none developed graft-versus-host disease, but one had viral sepsis and a clot in the kidney's artery11.

This is durable remission of the drug requirement in a few people, not a cure, and the series are small and uncontrolled.

Lab-grown and bioprinted organs

Early A 2023 review says moving from printed tissue models to real medical use is still a challenge, that capillaries cannot be built by direct printing, and that current technology cannot yet meet the needed precision, efficiency, and cell compatibility at the same time. The authors set goals of implantable volumetric organs in about 5 years, full-size transplantable organs in about 15, and patient-matched organs in about 30. Those are goals, not forecasts12. In the sources I opened, I found no bioprinted solid organ transplanted into a person.

Early (approved, but a vessel, not an organ). On December 20, 2024, the FDA announced its approval of Symvess, the first acellular tissue-engineered vessel, for adults with an arterial injury in an arm or leg who urgently need blood flow restored to avoid losing the limb and whose own vein can't be used. In a single-arm study of 54 patients, 67% kept primary patency (blood flowing with no further procedure) at day 30, and 15% had an amputation of the treated limb by month 36; its serious risks include graft rupture, anastomotic failure, and thrombosis13. It is a real approval of engineered tissue, based on a small uncontrolled study, and it is a long way from a kidney or a heart.

Related: in June 2023 the FDA approved Lantidra, an islet cell therapy made from deceased-donor pancreas cells, for adults with type 1 diabetes whose repeated severe hypoglycemia keeps them from reaching their HbA1c target despite intensive management. In its two single-arm studies, 21 of 30 participants did not need insulin for a year or more, though a majority had at least one serious adverse reaction tied to the procedure and the immunosuppressive drugs17. The newer diabetes cell therapies are on the heart and diabetes frontier page.

Bioprinting in orbit

Early Small pieces of tissue have been printed on the International Space Station. No organ has been, and I found no source showing Elon Musk or SpaceX printing organs. SpaceX's part is the ride: its cargo and crew flights carried printers, supplies, and samples.18,19,20,21

  • Russia, 2018. 3D Bioprinting Solutions' Organ.Aut magnetic bioprinter reached the station on Soyuz MS-11 on December 3, 2018, and cosmonaut Oleg Kononenko printed human cartilage tissue and a rodent thyroid gland, which the company calls a first in orbit.22 The team's peer-reviewed paper, with Kononenko as a coauthor, describes 3D tissue constructs assembled in microgravity from spheroids of human cartilage cells, which it calls the first made in space.23
  • Techshot and Redwire, 2019 to 2023. The BioFabrication Facility was built by Techshot with nScrypt and is now owned and operated by Redwire Space. It launched on SpaceX's CRS-18 cargo mission in 2019 and made its first prints that December with human heart cells.18,19 Materials for test prints of a partial human meniscus went up on SpaceX's CRS-20 in March 2020, and NASA astronaut Andrew Morgan prepared the printer for those prints.19 An upgraded unit flew on Northrop Grumman's NG-18 cargo mission.24 Redwire says the upgraded printer made a human knee meniscus in July 2023 with the Uniformed Services University's 4D Bio3 center, cultured it on the station for 14 days, and sent it home on SpaceX's Crew-6 flight (a company press release, not peer-reviewed).20
  • Auxilium Biotechnologies, 2026. Trade-press and news reports of the company's announcement say its AMP-1 orbital printer made kidney and liver tissue from cells supplied by the Wake Forest Institute for Regenerative Medicine, plus cartilage and 28 nerve-repair implants, and that the samples returned on SpaceX's CRS-34 mission on June 17, 2026. These are company claims reported by the press, not peer-reviewed results.21,25

SpaceX and Elon Musk. SpaceX flew the hardware, the supplies, and the samples home. I found no statement from Musk about printing organs in orbit. A 3Dnatives story about Musk planning 3D-printed wombs for Mars was the site's own April Fools' joke, and the site says that as far as it knows, Musk isn't looking into bioprinting to help populate Mars.26

Still unknown. What has come back from orbit is small tissue samples, not transplant-ready organs; threading blood vessels through thick tissue is still unsolved, and the nearer use is research such as drug testing.25 The ISS National Lab said in 2019 that a printed human lung or other organ is likely many years away.18

Cautions

  • This page describes research, and it is not a recommendation to seek any procedure.
  • Every pig-organ result here is a single patient or a brain-dead recipient. As of November 2026, I found no published results from the formal xenotransplant trials in anything I opened.
  • My only source for the Looney kidney is a news report, and the formal-trial clearances are described by a blog post and an editorial, not by the FDA or the sponsors2,14,15.
  • One machine perfusion trial was funded by the device maker, and the liver trial did not show a survival difference8,9.
  • The bioprinting timelines are the authors' goals, not predictions12.

References

  1. Riella LV, Borges TJ, Rosales IA, Avillach CT, Palsson R, Hullekes F, et al. Porcine kidney xenotransplantation as a bridge to allotransplantation: a first-in-human study. The Lancet, 2026.ArticlePubMed 42692038 · DOI

    What it found: Case report of the first recipient of eGenesis's gene-edited pig kidney (EGEN-2784) at Massachusetts General Hospital, transplanted January 25, 2025. The patient stayed off dialysis for 271 days; early T-cell rejection on day 14 resolved, then the graft failed after immunosuppression was reduced during an infection, and 82 days after removal the patient received a human kidney that worked immediately, with no sensitization over 231 days. No porcine pathogen transmission was detected.

    Limits: One patient under an expanded-access protocol, funded by Massachusetts General Hospital and eGenesis, so it shows feasibility as a bridge and not routine durability.

  2. Shaw C. Alabama woman has pig kidney removed after a record 130 days. KTVU FOX 2 (with AP contributions), April 13, 2025.ArticleRead

    What it found: News report that Towana Looney, 53, of Alabama had her gene-edited pig kidney removed at NYU Langone Health on April 4 after 130 days because her body began to reject it; surgeon Robert Montgomery cited a prior infection, slightly lowered anti-rejection drugs, and a reactivating immune system, and she returned to dialysis.

    Limits: A news report; I found no peer-reviewed paper on this case.

  3. Ribas GT, Cunha AF, Avila JP, Giarraputo A, Morena L, Lima K, et al. Immune profiling in a living human recipient of a gene-edited pig kidney. Nature Medicine. 2026;32(1):270-280.Lab or mechanistic studyPubMed 41507576 · DOI

    What it found: High-dimensional immune profiling of one living recipient of a gene-edited pig kidney. Early T-cell-mediated rejection occurred within 1 week and reversed with intensified immunosuppression; afterward adaptive immunity stayed suppressed but innate immune activation persisted, no antibody-mediated rejection was detected, and pig cell-free DNA rose during rejection and fell with treatment.

    Limits: One patient, a different recipient of the same eGenesis kidney from the Lancet bridge-to-transplant case, so the immune signatures and the cell-free DNA biomarker idea are hypotheses to test, not established rules.

  4. Griffith BP, Goerlich CE, Singh AK, Rothblatt M, Lau CL, Shah A, et al. Genetically Modified Porcine-to-Human Cardiac Xenotransplantation. The New England Journal of Medicine, 2022.ArticlePubMed 35731912 · DOI

    What it found: Case report of a 57-year-old man with nonischemic cardiomyopathy on ECMO who received a heart from a pig with 10 gene edits, with CD40-blockade-based immunosuppression. He was weaned from ECMO and the graft worked normally until day 49, when it suddenly thickened and failed; life support was withdrawn on day 60.

    Limits: One patient who was too sick for a human heart, with a graft failure the authors could not fully explain.

  5. Tao KS, Yang ZX, Zhang X, Zhang HT, Yue SQ, Yang YL, et al. Gene-modified pig-to-human liver xenotransplantation. Nature, 2025.ArticlePubMed 40140580 · DOI

    What it found: A six-gene-edited pig liver was transplanted as an auxiliary graft into one brain-dead recipient and monitored for 10 days. Bile production began about 2 hours after reperfusion and reached 66.5 mL by day 10, porcine albumin rose, and histology showed no signs of rejection.

    Limits: One brain-dead recipient followed for 10 days, so it shows early function and not survival of a living patient.

  6. Zhang W, Xu Q, Xu K, Jiang R, Wang S, Zheng M, et al. Genetically engineered pig-to-human liver xenotransplantation. Journal of Hepatology, 2026.ArticlePubMed 41076089 · DOI

    What it found: Case report of the first genetically modified pig auxiliary liver in a living person, a patient with a large liver cancer; the 10-edit graft showed metabolic function and bile secretion, but on day 38 it was removed because of xenotransplant-associated thrombotic microangiopathy, and the patient died on day 171 after repeated upper gastrointestinal bleeding.

    Limits: One patient, and the PubMed record lists an erratum (J Hepatol 2026;85(2):431) that I did not read.

  7. He J, Shi J, Yang C, Peng G, Ju C, Zhao Y, et al. Pig-to-human lung xenotransplantation into a brain-dead recipient. Nature Medicine, 2025.ArticlePubMed 40855190 · DOI

    What it found: A lung from a six-gene-edited pig was transplanted into a 39-year-old brain-dead man and monitored for 216 hours with no hyperacute rejection or infection. Severe edema appeared at 24 hours, and antibody-mediated rejection appeared to damage the graft on days 3 and 6, with partial recovery by day 9.

    Limits: One brain-dead recipient followed for 9 days, so it cannot show how a living patient would do.

  8. Nasralla D, Coussios CC, Mergental H, Akhtar MZ, Butler AJ, Ceresa CDL, et al. A randomized trial of normothermic preservation in liver transplantation. Nature. 2018;557(7703):50-56.Randomized trialPubMed 29670285 · DOI

    What it found: Randomized trial of 220 liver transplants comparing normothermic machine perfusion with conventional cold storage. Perfusion cut graft injury by 50% (enzyme release), cut the organ discard rate by 50%, and allowed a 54% longer mean preservation time, while bile duct complications, graft survival, and patient survival did not differ significantly.

    Limits: Not powered to show better survival, and it tested livers only.

  9. Schroder JN, Patel CB, DeVore AD, Bryner BS, Casalinova S, Shah A, et al. Transplantation Outcomes with Donor Hearts after Circulatory Death. The New England Journal of Medicine. 2023;388(23):2121-2131.Randomized trialPubMed 37285526 · DOI

    What it found: Randomized noninferiority trial of hearts from circulatory-death donors (perfused outside the body) versus standard brain-death donor hearts, with 180 patients transplanted (90 in each group). Risk-adjusted 6-month survival was 94% in the circulatory-death group and 90% in the brain-death group, and noninferiority was met.

    Limits: Six-month survival in one trial funded by TransMedics, which makes the perfusion device, so it does not show longer-term results.

  10. Kawai T, Sachs DH, Sprangers B, Spitzer TR, Saidman SL, Zorn E, et al. Long-Term Results in Recipients of Combined HLA-Mismatched Kidney and Bone Marrow Transplantation Without Maintenance Immunosuppression. American Journal of Transplantation. 2014;14(7):1599-1611.Cohort studyPubMed 24903438 · DOI

    What it found: Ten patients received HLA-mismatched kidney and bone marrow transplants. Immunosuppression was stopped for 4 or more years in seven; four remained off drugs for 4.5 to 11.4 years, three resumed after 5 to 8 years, and 3 of the 10 kidneys failed from thrombotic microangiopathy or rejection.

    Limits: Ten patients in a single-center series without a randomized control group.

  11. Leventhal J, Abecassis M, Miller J, Gallon L, Ravindra K, Tollerud DJ, et al. Chimerism and Tolerance Without GVHD or Engraftment Syndrome in HLA-Mismatched Combined Kidney and Hematopoietic Stem Cell Transplantation. Science Translational Medicine, 2012.ArticlePubMed 22399264 · DOI

    What it found: Eight recipients of HLA-mismatched kidneys plus bioengineered stem and facilitating-cell grafts received fludarabine, 200-cGy total body irradiation, and cyclophosphamide. Five had durable chimerism and donor-specific tolerance and were weaned off all immunosuppression 1 year after transplant, and no recipient developed graft-versus-host disease.

    Limits: Eight patients, no randomized comparison, and the abstract reports follow-up only through the first year.

  12. Wang H, Liu X, Gu Q, Zheng X. Vascularized organ bioprinting: From strategy to paradigm. Cell Proliferation. 2023;56(5):e13453.ReviewPubMed 36929675 · DOI

    What it found: Review arguing that 3D bioprinting is the most promising route to vascularized organs made in the lab, but that moving from simple tissue models to real biomedical use is still a challenge. The full text proposes a three-stage set of goals ending in patient-matched organs, says capillaries cannot be built by direct printing, and says current technology cannot yet meet precision, efficiency, and cytocompatibility requirements together.

    Limits: A 2023 review whose timelines are the authors' goals, not forecasts, and it reports no new data.

  13. U.S. Food and Drug Administration. FDA Approves First Acellular Tissue Engineered Vessel to Treat Vascular Trauma in Extremities. FDA press announcement, December 20, 2024.Regulatory noticeRead

    What it found: FDA announcement approving Symvess, an acellular lab-grown blood vessel, as a conduit for adults with extremity arterial injury when urgent revascularization is needed and a patient's own vein graft is not an option. In a single-arm study of 54 patients, 67% kept primary patency at day 30 and 15% had an amputation of the treated limb by month 36; warnings include graft rupture and thrombosis.

    Limits: A single-arm study of 54 patients, and the product is a blood vessel for trauma, not a solid organ.

  14. Deeley M. FDA greenlights first clinical trials for genetically modified pig kidney transplants in humans. American Kidney Fund, February 6, 2025.ArticleRead

    What it found: Patient-organization blog post dated February 6, 2025, reporting that two companies had received FDA go-aheads: United Therapeutics' trial would start with six patients and expand to 50, for adults aged 55 to 70 on dialysis for at least six months, while eGenesis's study would be three patients under an expanded access protocol.

    Limits: A secondary blog post relaying news coverage, with no exact clearance dates, so the trial terms should be checked against the sponsors and ClinicalTrials.gov.

  15. Nashan B. The First Clinical Renal Xenotransplantation Study (EXPAND): Evaluating Safety, Function, and Zoonotic Risks. Health Care Science, 2025.ArticlePubMed 41451389 · DOI

    What it found: Editorial describing United Therapeutics' EXPAND trial (NCT06878560), the first regulated clinical trial of a gene-edited pig kidney (UKidney): an open-label, single-arm, multicenter study with an initial cohort that is to expand pending a safety review, NYU Langone Health as the first site, and a first transplant announced in November 2025. The trial's age range, cohort sizes, and endpoint timing are in the editorial's full text, not in an abstract.

    Limits: A one-author editorial with no abstract that is inconsistent about what "EXPAND" stands for, so trial details should be checked against the registry.

  16. Kawai T, Cosimi AB, Spitzer TR, Tolkoff-Rubin N, Suthanthiran M, Saidman SL, et al. HLA-mismatched renal transplantation without maintenance immunosuppression. The New England Journal of Medicine, 2008.ArticlePubMed 18216355 · DOI

    What it found: Five patients received combined kidney and bone marrow transplants from living donors mismatched at one HLA haplotype after nonmyeloablative conditioning. One had irreversible humoral rejection; in the other four all immunosuppression was stopped 9 to 14 months after transplant and kidney function stayed stable for 2.0 to 5.3 years.

    Limits: Five patients, no control group, and one lost the kidney to rejection.

  17. U.S. Food and Drug Administration. FDA Approves First Cellular Therapy to Treat Patients with Type 1 Diabetes. FDA press announcement, June 28, 2023.Regulatory noticeRead

    What it found: FDA announcement that Lantidra, a deceased-donor islet cell therapy infused into the liver portal vein, was approved for adults with type 1 diabetes and repeated severe hypoglycemia despite intensive management. In two single-arm studies of 30 participants, 21 did not need insulin for a year or more, and most had a serious reaction to the procedure or the immunosuppressive drugs.

    Limits: Two non-randomized studies; the islets need immunosuppressive drugs to survive, and some serious reactions forced those drugs to stop, which ended islet function and insulin independence.

  18. ISS National Laboratory. America's First Automated Bioprinter for Spaceflight Launching to ISS National Lab on SpaceX CRS-18. ISS National Laboratory press release, July 17, 2019.ArticleRead

    What it found: ISS National Lab press release saying the 3D BioFabrication Facility, built by Techshot with nScrypt's micro-dispensing tool head and now owned and operated by Redwire Space, would launch on SpaceX's CRS-18 Dragon mission no earlier than July 24, 2019, starting with simple engineering prints before cardiac-like tissue. It notes about 75,000 people on the U.S. organ waiting list and that building a human lung is likely many years away.

    Limits: A launch announcement, not results, and it does not mention Elon Musk.

  19. ISS National Laboratory. Our BFF Gets to Know the Knee. ISS National Laboratory (iss360), April 8, 2020.ArticleRead

    What it found: ISS National Lab article reporting that the BioFabrication Facility completed its first space-based prints in December 2019 with human heart cells and then made test prints of a partial human meniscus, with the meniscus materials launched in March 2020 on SpaceX CRS-20.

    Limits: A sponsor's news article, not a peer-reviewed result, with no tissue-quality data.

  20. Redwire Corporation. Redwire BioFabrication Facility Successfully Prints First Human Knee Meniscus on ISS Paving the Way for Advanced In Space Bioprinting Capabilities to Benefit Human Health. Redwire press release (rdw.com), September 7, 2023.ArticleRead

    What it found: Company press release, not yet peer-reviewed: Redwire says its upgraded BioFabrication Facility printed a human knee meniscus on the ISS in July 2023 with the Uniformed Services University's 4D Bio3 center, cultured it for 14 days in its ADSEP processor, and that the SpaceX Crew-6 mission brought it back to Earth.

    Limits: A company press release with no tissue data, so the 'first' claim and the quality of the print are Redwire's.

  21. Frost LS. The first kidney and liver tissue bioprinted in space, aboard the ISS. 3Dnatives, August 3, 2026.ArticleRead

    What it found: Trade-press report of Auxilium Biotechnologies' announcement that its AMP-1 orbital bioprinter made kidney and liver tissue, cartilage, and 28 nerve-repair implants on one flight, with cells and models from Wake Forest Institute for Regenerative Medicine; the samples returned to Earth on June 17, 2026, aboard SpaceX's CRS-34 mission.

    Limits: Based on the company's announcement, with no tissue-quality data, and the 'first' claim is Auxilium's.

  22. 3D Bioprinting Solutions. About the Laboratory. 3D Bioprinting Solutions (bioprinting.ru), 2018.ArticleRead

    What it found: The company says its Organ.Aut magnetic bioprinter was delivered to the ISS on December 3, 2018, aboard Soyuz MS-11 under an August 2017 agreement with RSC Energia, and that cosmonaut Oleg Kononenko printed human cartilage tissue and a rodent thyroid gland, which it calls the first such printing in orbit.

    Limits: The company's own page, undated, so the claims are the company's.

  23. Parfenov VA, Khesuani YD, Petrov SV, Karalkin PA, Koudan EV, Nezhurina EK, et al. Magnetic levitational bioassembly of 3D tissue construct in space. Science Advances. 2020;6(29):eaba4174.Lab or mechanistic studyPubMed 32743068 · DOI

    What it found: The authors biofabricated 3D tissue constructs from human chondrocyte spheroids in microgravity aboard a space mission, which they describe as a first. Spheroid fusion matched their models, and the constructs showed good cell viability.

    Limits: A small cartilage-tissue experiment, not an organ, and the abstract gives no numerical results.

  24. ISS National Laboratory. NG-18 Research: RedWire BioFabrication Facility. ISS National Laboratory, November 3, 2022.ArticleRead

    What it found: ISS National Lab page saying an upgraded Redwire BioFabrication Facility, a 3D bioprinter for human tissue, traveled to the station on Northrop Grumman's 18th commercial resupply mission (NG-18), aiming to advance in-space bioprinting of tissues and possibly organs in the future.

    Limits: A mission preview that does not name SpaceX or Elon Musk and reports no results.

  25. The Next Web. A startup just 3D-printed kidney and liver tissue in space, a first. The Next Web, July 9, 2026.ArticleRead

    What it found: News report on Auxilium Biotechnologies' announcement. It says the samples are small and not transplant-ready organs, that a printed kidney for patients is still years away with blood-vessel formation unsolved, and that the near-term use is research such as organoids for drug testing.

    Limits: Reports the company's own announcement, with the caveats coming from the article, not a trial.

  26. 3Dnatives. Elon Musk Hopes to Enable Human Reproduction on Mars With 3D Printing. 3Dnatives, April 1, 2025.ArticleRead

    What it found: An April Fools' Day piece describing an invented 25-year Mars plan with 3D-printed artificial wombs, whose own disclaimer calls it a joke and says that as far as the publisher knows Musk is not pursuing bioprinting to populate a Mars colony.

    Limits: A satire, cited only to flag that it exists and is not evidence of anything Musk said or did.