Frequently Asked Questions by Patients

Basics: device and function

1. How does the device work? And how big is the device?

The bioartificial kidney, the size of a coffee cup, consists of two modules that work together to get rid of wastes. First, a hemofilter module processes incoming blood to create a watery ultrafiltrate that contains dissolved toxins as well as sugars and salts. Second, a bioreactor of kidney cells processes the ultrafiltrate and sends the sugars and salts back into the blood. In the process, water is also reabsorbed back into the body, concentrating the ultrafiltrate into “urine,” which will be directed to the bladder for excretion.

2. What is the surgical process like to insert the device? Where can I have the procedure done?

The procedure will be similar to kidney transplant surgery and it will be performed under general anesthesia. Once the bioartificial kidney device is available publicly, the procedure can be completed at any hospital with a trained transplant surgical team.

3. How will the filter be cleaned?

The filter is coated with a special thin biocompatible film to prevent fouling and blood clots. Additionally, the blood flowing over the coated filter surface will also help to keep the membrane free of debris accumulation.

4. How long will the device survive after implantation? Will it have to be replaced?

The device is meant to be permanent and that is what our efforts are pushing towards. Current testing and research suggest that it could be possible for the device to operate for many years, without failure. However, if failures occur, the replacement of the filter and/or cells would likely involve a minimally invasive surgery.

5. Will patients still have to take immunosuppressive drugs or anticoagulant after implantation? Will there be a risk of blood clotting?

The cells in the bioreactor are isolated from the patient’s immune system by the scaffold on which they are grown. The coatings on the device work to prevent blood clotting. In earlier human trials of a large scale bioartificial kidney, no antirejection drugs were needed, and in recent preclinical experiments, no blood thinners were needed.

6. How are the cells in the bioreactor simultaneously isolated from the immune system but still kept alive?

The immunoisolation is provided by the membranes on which the cells are grown. The cells are grown on a porous scaffold which allows water, salts, glucose, amino acids, and other very small molecules to pass through it freely. These nourish the cells and allow the cells to dispose of small wastes, such as carbon dioxide.

The immune system relies on fairly large molecules to identify and attach foreign intruders, which are a thousand times larger than, say, glucose. They are too large to penetrate the sieve of the membrane supporting the cells.

7. Will it also help Polycystic Kidney Disease and Focal Segmental Glomerulosclerosis (FSGS)?

Yes. In any case where a kidney transplant is needed, our device will be a viable option.

8. Will the "cell reactor" part of your kidney be able to generate Erythropoietin and eliminate the need for artificial EPO injections?

The kidney cells in the bioreactor are different cells than the cells that secrete erythropoetin.

9. What kind of GFR value would you expect to see once this device gets implanted in you? How much increase in GFR might occur?

While this will be confirmed as we progress through preclinical studies, we anticipate a GFR value of 20-30 ml/min with this device implanted.

10. Can you still get this device if you still have 15% kidney function? Or is it exclusive to those whose kidneys have totally failed?

This is case-specific, so it would depend on the details of a particular patient’s case and will be decided by both the patient and physician.

11. Will this be available internationally? Or will international patients have to go to United States for procedure?

Once the device is released commercially, it will be available to all patients in need, domestic or international. Clinical trials, however, will likely be conducted in the United States initially because it is where the key research is taking place as well as needing to adhere to all FDA guidelines.

12. Any predicted side effects?

Adverse side-effects that might occur would be similar to side effects known in other procedures involving implanted medical devices. These include complications like surgical trauma, scars, and infections. Additionally, there might be a need for increased fluid consumption.

13. How much will this device cost?

We anticipate that the device will cost no more than what transplant costs. It is challenging to put a dollar figure on procurement, implantation, and monitoring in the future due to what the business and economic climate will be at the time the device is released.

14. Will this device be covered by insurance?

Generally, medical devices that are successful are products for which insurance provides coverage. Our analysis suggests that the implantable bioartificial kidney will be associated with over 50% cost savings compared to dialysis and, as such, we anticipate that the device will be attractive to those considering coverage decisions.

15. What are the challenges (long term and short term)?

The Kidney Project is an ambitious project and is not without its challenges. In the short term, our primary challenge is funding the research and development. A significant hurdle is procuring enough money in order to complete the preclinical studies for both device components, and build full-scale prototypes for the first rounds of in-human studies.

The long term challenges center around keeping the device operating trouble-free after implantation beyond a few months. Some problems won’t become clear until we do clinical trials, so for now, we are looking at ways to increase the lifetime of cells as well as ways to minimize, or even eliminate, thrombus formation (blood clotting). We will get a better handle on the long-term challenges once we transition to preclinical studies and begin to gather clinical-scale data.

16. I am waiting for the implantable bioartificial kidney, but my physician or health care provider is recommending that I start dialysis. Or I am going on the kidney transplant list. What should I do?

We recommend that you heed the advice of your physician or other qualified health provider, as they best understand the needs of their individual patients. Please do not delay any recommended treatments.

The implantable bioartificial kidney is still under development and it will address the current limitation of donor organs. While our device will be a revolutionary, alternative solution to kidney failure patients, it will not surpass the performance of a natural, healthy kidney.

17. Why did The Kidney Project partner with Home Dialyzors United (HDU), and what does that partnership mean?

In spring of 2017, The Kidney Project announced a new partnership with Home Dialyzors United. We are very excited about the opportunities this partnership will bring, and believe it is an important milestone for The Kidney Project.

Partnerships with patient-advocacy groups, such as HDU, allow The Kidney Project to access the opinions and the unique perspectives of kidney disease patients, helping to improve the bioartificial kidney device for all users. The FDA (Food and Drug Administration) encourages medical device developers to incorporate patient perspectives, acknowledging that their voice is often unheard in the medical device development process.

HDU works tirelessly within today’s legal and medical systems to advocate for, and inform dialysis patients about their options for dialysis care. We have partnered with HDU because of their advocacy experience, and their deep understanding of the daily obstacles presented to dialysis patients, and their loved ones.


18. What can be done to speed up the research and development process?

Our progress is driven by two components: time required to conduct scientific analysis and development, and funding. The scientific analysis and development process cannot necessarily be forced into a faster pace. Because we are developing a novel device and are held to the safety standards of the FDA, we must maintain scientific rigor and technical excellence in a logical order without skipping steps.

However, additional funding allows us to hire more personnel, expedite our ordering, purchase additional equipment and generally complete tasks faster. Therefore, donations, fundraisers, and federal funding all help to speed up the research and development process. In short, more funds allow us to operate at a faster pace.

19. How long will clinical trials take to complete?

There are several required steps in the clinical trials process.

Our initial clinical trial is a material safety test of the Hemofilter. During this trial, we will confirm that all the materials included in our Hemofilter component are safe for human blood exposure. This is the first step of many to receive FDA approval for a completed bioartificial kidney device.

Once our initial clinical trial is complete and the data analyzed, we will apply for a follow-up study to test the Hemofilter’s functional components, namely its ability to sufficiently filter human blood. Subsequent clinical tests will focus on verifying individual components of the Hemofilter until we graduate into full device implantation in humans.

A truncated series of clinical trials will then be required for the combined Hemofilter and Bioreactor device, i.e. the bioartificial kidney. After these trials are completed successfully, the bioartificial kidney will be available to the public.

We expect to arrive at this final stage of clinical trials by late 2021. This scenario assumes that we have sufficient funding and no unanticipated scientific, technical, or regulatory drawbacks.

20. When will the device be ready after clinical trials?

See: How long will the clinical trials take to complete, above.

During the clinical trials, we will be working with manufacturers to discuss and manage the details of production. Once the clinical trials are complete, the device will be made available for patients.


21. How much more money do you need to finish preclinical testing?

We have successfully raised all funds necessary to complete preclinical testing of the Hemofilter component. To finish preclinical testing of the Bioreactor, we still need an additional $3 million.

22. How much more money do you need to finish clinical trials?

At this time, we’re not sure how much all the clinical trials will cost, because we don’t know precisely how many trials will be required, and the cost of a single clinical trial is significant.

To complete the initial clinical trials, we anticipate an additional $5 million will be needed. These funds include the $2 million that is required for Hemofilter safety testing, and $3 million for the combined Bioreactor and Hemofilter device testing.

23. What kind of federal funding do you receive? How do you get more?

In 2015 The Kidney Project was awarded $6 million from the National Institute of Health (NIH) to be distributed over the next four years -- $1.5 million per year. In addition, The Kidney Project has received an additional almost $7 million from various federal agencies in the United States including NIH, National Aeronautics and Space Administration (NASA) and the Department of Defense (DOD). These agencies have provided federal funding for the basic research and groundwork behind the artificial kidney. We have since received very positive feedback from these federal agencies, recognizing our success with the fundamental proof-of-concept work. In order to proceed to the next steps in commercialization, we now need the help of industry partners and investors. However, as mentioned below, the challenge with procuring these industry partners and investors is that they want to see more data from preclinical studies before they invest.

24. Why do you not have a lot of investors? Is it too risky for them?

Investors have expressed interest in our project and have indicated its potential. Additionally, they have also commented that their comfort with investing in our project would increase significantly once we can show them human safety studies.

25. Is it worth contacting our government officials to ask for more funding to your project?

Yes, absolutely! The Kidney Project’s artificial kidney will enhance patient outcomes and reduce treatment costs, which provides an overall improvement to the patients’ quality of life and current healthcare costs. Writing to your congressional representatives lets them know about The Kidney Project's potential impact.

26. How can I make a donation? (Domestically and Internationally)


Make a gift.


  1. Make checks payable to UCSF Foundation.
  2. Include allocation instructions on the memo line: The Kidney Project.
  3. Send gifts by U.S. Mail to:

    P.O. Box 45339
    San Francisco, CA 94145-0339


Call toll-free 877-499-UCSF (877-499-8273) to charge by phone.

Clinical trials: before and after

27. What is the status of preclinical testing?

The Kidney Project is in the midst of preclinical testing for the Hemofilter, while preclinical testing for the Bioreactor has just begun.

Results from preclinical testing of the Hemofilter are encouraging. We have successfully implanted the Hemofilter component into large animal models for up to 1 month. The animals responded well, without serious complications. We have collected enough preclinical data to apply for our first clinical trial, but are still acquiring the data that we need to convince private investors to fund our project.

28. Do you have a waitlist for clinical trials? How do I sign up?

If you are interested in potentially participating in the clinical trials, complete this form to submit your information into our [confidential] database:


We can’t guarantee anyone’s participation since this is not an official wait-list. We will contact everyone in our database after we receive clinical trial approval.

29. I filled out the form to be included in clinical trials – now what?

Thank you for your interest in participating in our upcoming clinical trials. Each clinical trial will include a round of patient selection for involvement. Until we have clearance from our Institutional Review Board (IRB), we are unable to release any patient involvement criteria for our studies. Once each trial receives approval, our team of doctors are allowed to begin the recruitment process. We will message all individuals in our database to alert them of our progress and provide information concerning the next steps.

30. Who decides who will participate in the clinical trials? If I donate, will that increase my chances of participation?

To ensure the clinical trials are conducted safely and without bias, all patient selection decisions are led by our medical team. None of The Kidney Project management or staff are able to contribute or personally recommend any particular individual for participation in the trials. While donations are hugely appreciated and continue to serve a vital role in our project’s funding, no donations are accepted under the expectation of payment to be involved in our trials. This is to protect the integrity of our project and ensure that all participant decisions are made for medically and scientifically sound reasons.

31. Where will the clinical trials take place?

Clinical trials will likely take place at multiple locations within the United States. As with patient criteria, the location of each clinical trial will not be confirmed until trial approval is granted. The first clinical trial will likely take place in San Francisco, CA or Nashville, TN, as these are the locations where the majority of The Kidney Project team is based.

32. What are the criteria for choosing the first group of clinical trials patients?

We are not allowed to share patient criteria for participation in our clinical studies until after our studies receive approval. Once approval is given, we will message all individuals in our online database to provide information about next steps.

33. Will stage 4 patients be accepted?

The initial clinical trials will concentrate on End Stage Renal Disease patients.

34. Will international patients be considered?

International patients will certainly be considered. However, it is likely that the first round of patients will be domestic due to hospital logistics and operating under FDA (Food and Drug Administration) guidelines.

35. Will there be a trial for pediatric patients?

Safety will be our main concern during the initial phase of clinical trials, so we do not intend to use vulnerable populations, such as children, until after we have positive and consistent data from clinical trials with adults.

36. Will the clinical trials be fully funded or will the patients need to help with funding their participation?

Ideally, if we have procured all necessary funding, the clinical trials should be fully funded. We will know more details after the successful completion of our first clinical trial, and will update everyone accordingly.

37. What is the current timeline of clinical trials now?  Why have there been delays?

When we projected a timeline where clinical trials begin in 2020, it was our most favorable scenario at the time. Our projected timeline has always been dependent on obtaining the required funding, and not encountering unanticipated scientific hurdles.

In 2020, the global community faced the COVID-19 pandemic. Thereby, we must acknowledge that it is inevitable that our timeline for starting the first clinical trials has been adversely impacted.

We went through an abrupt stoppage of lab operations in March. We gradually reopened lab activities in the subsequent summer months, with a strict adherence to local guidelines and our organizations’ policies. Unfortunately, we were also facing supply chain interruptions and backlogs at testing facilities, which also held back the overall progress of our reopening. Eventually, we brought up our lab staff to 50% in September. And as local COVID-19 numbers continued to rise in November, we had to bring that back to 25% in December. Currently, we are still at this limited capacity and operations.

We are committed to advancing the development of the bioartificial kidney to patients as quickly as possible. Currently, we estimate that our delay may be 6 to 9 months from our original projection. We remain hopeful that we will be able to start the initial clinical studies in 2021; however this is dependent upon the projection that the COVID-19 situation improves and will allow us to ramp up in operations in early 2021.

We appreciate your patience, understanding, and continued faith in The Kidney Project. We will continue to do our utmost to deliver a safe and effective bioartificial kidney to patients as quickly as possible.

38. The Kidney Project's Facebook page mentions something called iHEMO. What is iHEMO?

iHEMO refers to the hemofilter component of the implantable bioartificial kidney which is connected to an external dialysate recirculation pump, allowing patients to do frequent and prolonged hemodialysis from the comfort of their homes.Unlike standard hemodialysis, iHEMO would not need a needle-based vascular access and its compact design will allow for greater lifestyle flexibility.

39. Where can I find updates regarding the progress of the project?

Our Facebook page is a great place to stay informed about our progress: The Kidney Project on Facebook.

In addition, we keep an archive of news stories on our site at News and Events.

Refer to the UCSF Fundraising Event Guidelines for more information regarding the use of the UCSF logo, financial and legal information, liabilities, and fundraiser approval.

Contact us at [email protected] with additional questions or for information about fundraising.