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Frequently Asked Questions about Clinical MSCs

As a partner in your regenerative medicine development project, REPROCELL offers off-the-shelf cGMP and Research use MSCs from various sources. Additionally, with our CDMO partner Histocell, we can manufacture cGMP MSC Master Cell Banks (MCB) that are compliant with the current regulatory and manufacturing standards of the FDA and the EMA. We are committed to assisting your project by providing all necessary quality and regulatory documents.


A. General

1. What are mesenchymal stem cells?

Mesenchymal stem cells (MSCs), also referred to as mesenchymal stromal cells, are multipotent adult stem cells. They are a group of cells that exist in various tissues of the body, which can self-renew by dividing and can differentiate into various tissues including, bone, cartilage, adipose tissue (fat cells), connective tissue and muscle. These cells possess a unique set of characteristics, including anti-inflammatory, immunomodulatory, and regenerative properties, making them an attractive option for the treatment of a diverse range of medical conditions. MSCs can therefore be used as a direct therapeutic agent or for their potential to differentiate into clinically relevant somatic cell types and tissues. Additionally, these cells are generally immunosuppressive, but they may not always have low immunogenicity as some studies show that they are cleared but do not always persist at sites of transplantation. Generally, MSCs show a lower rejection compared to other cell types and may potentially not require a donor-patient match, and therefore the risk of rejection is much reduced. (Le Blanc et al., Exp Hematol 31:890 (2003))

2. Are MSCs safe for cell therapy?

Bone marrow-derived MSCs are considered to have an excellent safety profile, and multiple peer-reviewed studies have found them to be safe. See for example this publication Wang, et al., Stem Cell Res Ther 12:545 (2021)

3. What are the types of mesenchymal stem cells?

MSCs are categorized based on the origin, such as bone marrow-derived MSCs (BM-MSCs), umbilical cord MSCs, adipose-derived MSCs (ASCs), heart MSCs or lung MSCs.

4. What are Repro MSC mesenchymal stem cells? (See also section B.2.)

Repro MSCs are human iPSC-derived MSC lines differentiated from REPROCELL’s research-use RNA-iPSCs with minimal lot-to-lot variability, while still retaining the potential to differentiate into all 3 MSC lineages (adipocytes, chondrocytes and osteocytes). We currently offer these as off-the-shelf lines for research use only. If you are interested in a custom service project, please make an inquiry.

5. Which media is used to expand mesenchymal stem cells in culture?

All our MSC cell products are derived under xeno-free conditions. Standard culture MSC culture medium with DMEM and serum (e.g. human platelet lysate (hPL) or FBS) can be used or the defined medium MSC Nutristem XF Medium and related reagents. A protocol for culture in MSC NutriStem is available. Thawing, Passaging, Culturing, and Cryopreservation of Human MSCs (PDF)

6. What are MSC exosomes and the secretome?

Exosomes are small, lipid-bound sacs filled with fluid (extracellular vesicles) which mediate intercellular communication. Exosomes range in size from 30-150 nanometers in diameter and carry nucleic acids, proteins, lipids and other metabolites. MSC-derived exosomes have been found to contain growth factors relevant to regeneration and repair functions in the body.

The MSC secretome is the set of molecules and biological factors that are secreted by cultured MSCs into the extracellular space to induce paracrine actions between cells. All factors secreted by MSCs can be isolated and harvested. The secretome includes the micro-vesicles and exosomes, but also other important factors such as growth factors and cytokines, and it has been shown to promote immune modulation and tissue modulation during various applications in regenerative medicine therapy. (Ghasemi et al., Stem Cell res Ther 14:122 (2023))

In the past decade, exosome- and secretome-based therapies have emerged as a promising approach to overcome the limitations associated with cell-based therapies for tissue and organ regeneration. In some countries exosomes are regularly applied topically to the skin for beauty treatments.

Currently we do not have exosomes or secretomes products as catalogue items, but they can be made available as a custom item. Please inquire at

B. MSC ready to use products on REPROCELL’s web page

1. Primary Human Bone marrow (BM)-derived MSCs

i. What are BM-derived MSCs?

The BM-MSCs are derived from bone marrow donated by young and healthy individuals, ensuring high-quality cells. The donors are typically between the ages of 18-28 and undergo extensive health checks before donating. Once the bone marrow is donated, the cells are cultured in Cellcolabs’ state-of-the-art production facility in Solna/Stockholm, located adjacent to the world-renowned Karolinska Institute. One donation can provide up to 100 treatments, depending on the specific indication.

ii. What is the donor consent and donor recruitment process?

The MSCs are harvested from ethically sourced bone marrow of healthy donors 18-28 years old and cultivated following stringent production procedures in a cGMP manufacturing facility at the Karolinska Institute Campus in Stockholm Sweden. Donors are de-identified and, after tissue collection, are referenced by a unique ID. The donor-ID link is maintained only at the collection site. The consent form and all documents containing the donor identifiers are kept at the collection site in accordance with Cellcolabs Quality management Systems (QMS). The whole process follows EMA COMMISSION DIRECTIVE 2006/17/EC, 2006/86/EC and 2004/23/EC OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 31 March 2004, which sets standards of quality and safety for the donation, procurement, testing, processing, preservation, storage and distribution of human tissues and cells.

There is data indicating that MSCs from younger donors are more potent than from older ones, which is why Cellcolabs’ donors are young and rigorously screened prior to donation.

iii. What are cGMP BM-MSCs?

Every step in the process is quality controlled, and the cGMP grade MSCs are approved by the Swedish MPA (Swedish Medical Product Agency) and follows the principles and guidelines of Good Manufacturing Practice laid down in Directive (EU) 2017 /1572 and Commission Delegated Regulation (EU) 2017/1569. These requirements fulfil the cGMP recommendations of the World Health Organization (WHO). The whole process from donation, procurement, testing, processing, preservation, storage and distribution of human tissues and cells follows EMA COMMISSION DIRECTIVE 2006/17/EC, 2006/86/EC and 2004/23/EC.

Because of the strictly regulated and controlled quality, the patient is assured to receive the intended amount and potency of cells.

iv. What is the difference between cGMP grade and Research grade BM-MSCs?

The process and the quality control criteria for research grade and cGMP-grade MSCs are the same with the following differences: Prior to tissue acquisition it is defined if the new batch will be processed for research or cGMP as this determines the necessary documentation for the cGMP product. The culture environment for manufacturing cGMP-grade MSCs is within a B-grade clean room, and the cGMP-grade MSCs are tested for chromosomal stability, which is not included in the research-grade MSC QC package.

v. How are the MSCs isolated?

Human mesenchymal stem cells are isolated based on their tissue origin. A Ficoll density gradient method is used to isolate mesenchymal stem cells from bone marrow.

vi. What are the characteristics of the off-the-shelf BM-MSCs, and which other batch release assays have been conducted?

Human viral pathogen testing has been conducted at the donor level prior to tissue acquisition. Expression of cell surface markers, including CD105, CD73 and CD90 and lack expression of CD45, CD34, CD14 or CD11b, CD79, or CD19 and human leucocyte antigen-DR (HLA-DR) are measured. Additionally, morphology, viability, endotoxin, sterility, mycoplasma tests and chromosomal stability (cGMP-grade MSCs only) have been conducted. Datasheets and CoA can be sent to you upon request.

vii. What does Xeno-free mean?

Xeno-free means that our cells are not exposed to any kind of animal derived compounds at any stage of production. In particular, no Fetal Bovine Serum (FBS) is used to culture our cells before cryo-preservation.

viii. Are cells from a single or pool of donors in each vial?

Cellcolabs’ hBM-MSCs are manufactured from bone-marrow obtained from healthy donors 18-28 years old. The cells are prepared from single donors in each vial.

ix. Do you offer MSCs at different passages?

The BM-MSCs are usually cultured and cryopreserved at passage 2 or 3, which maintains the highest potency of stem cells compared to older passages.

2. Repro MSCs (iPSC-derived MSCs)

i. What are Repro MSCs?

The Repro MSC are differentiated from human iPSCs using an in-house proprietary protocol optimized to generate MSCs with high levels of CD73, CD90 and CD105 expression. Repro MSC3 and Repro MSC4 are MSC lines with minimal lot-to-lot variability, while still retaining the potential to differentiate into all three MSC lineages (adipocytes, chondrocytes and osteocytes). Repro MSC3 and Repro MSC4 are differentiated from the same human iPSC line generated from fibroblasts of a 20-year-old Asian-Indian female using REPROCELLʼs 3rd gen RNA reprogramming technology. The hiPSC line has been fully characterized as a hiPSC and the quality control of Repro MSC3 and Repro MSC4 includes sterility, mycoplasma and viral pathogen testing, G-band karyotyping, and flow cytometry characterization (CD73+, CD90+, CD105+ and CD45−). Trilineage differentiation (osteocytes, adipocytes and chondrocytes) has also been successfully performed to confirm the optimization and robustness of our differentiation protocol.

ii. Donor consent and recruitment

a. What mechanisms were put in place for the protection of donor privacy and confidentiality?

Donors are de-identified and, after tissue collection, are referenced by a unique ID. The donor-ID link is maintained only at the collection site. The consent form and all documents containing the donor identifiers are kept at the collection site in accordance with Institutional Review Board (IRB) guidance, regulatory guidelines, and REPROCELL’s Quality Management System (QMS).

b. Regarding donor tissue material, is there evidence of free and voluntary informed consent, in conjunction with independent review and oversight, with particular attention given to disclosure of potential research, clinical and commercial applications?

All donors are consented, provided HIPPA authorization agreement, and provided the Subject Bill of Rights for Clinical collection. The IRB provides an independent review of the documents and practices governing our tissue collection protocols. The donor tissues are consented for research, commercial and clinical use.

Current Repro MSC3 and Repro MSC4 are for research use only. For commercial and clinical use, please contact us at

c. What are the regulations governing the acquisition of human donor tissues guiding REPROCELLs protocols?

Tissue acquisition by REPROCELL USA follows federal regulations that govern the use of human tissue.

Three important federal regulations may apply to the use of human tissue and associated data in research: the “Common Rule” (HHS, 45 CFR part 46 Subpart A), the US Food and Drug Administration (FDA) human subjects regulations (21 CFR part 50, 56, and 812), and the Health Insurance Portability and Accountability Act (HIPAA) Privacy Rule (45 CFR part 160 and Subparts A and E of part 164) and Security Rule (45 CFR part 160 and Subparts A and C of part 164). Bledsoe and Grizzle, Diag Histopathol (Oxford) 19:322 (2013)

These regulations ensure the safety and privacy of the donors.

C. Custom MSC Services for research and clinical projects

REPROCELL offers CDMO services to manufacture Advanced Therapies Medicinal Products (ATMPs) generated from mesenchymal stem cells (MSC) through a partnership with Histocell, a clinical-stage biopharmaceutical company specializing in developing cell therapy products for regenerative medicine. Histocell has established an authorized cGMP ATMP manufacturing facility in Bilbao, Spain. Histocell has been providing cGMP manufacturing services since 2011, and they are highly experienced in manufacturing clinical MSC products including cell-free MSC-derived secretome and exosome cell therapies for European and US customers. Around 300 patients have already been treated with ATMPs manufactured by Histocell, and more than 350 batches have been manufactured under cGMP. We provide all regulatory QC specified by the EMA or FDA, and all the required documentary support for the cells.

1. What kind of services can be provided?

The newly built 600 m2 cGMP facility is authorized and registered by the EMA for manufacturing clinical grade cells in compliance with cGMP guidelines of European Union Manufacturer Authorization (EMA) Regulation (EU) 2017/1569. Histocell manufactures investigational medicinal products for human use for European, US, and Japanese customers. Regulations in many other countries are harmonized with those of the FDA and EMA based on regulatory and quality aspects. Histocell can offer a wide range of custom cGMP services including creation of cGMP iPSC MCBs and cGMP MSC MCBs and related services.

Some of the available services include:

  • Isolation and expansion of autologous or allogeneic adult adipose-derived MSCs
  • Expansion of autologous and allogeneic adult bone marrow MSCs
  • Mesodermal Trilineage differentiation of MSCs (chondrocytes, osteocytes, adipocytes)
  • Production and characterization of cell-derived products like secretome and exosomes

2. Do I need to provide starting tissue like BM or adipose tissue?

No, REPROCELL can source these tissues for you based on your donor requirements. We also offer expansion services of research grade or cGMP- grade MSCs to create an cGMP MSC MCB from existing early passage MSCs (see section C1).

D. Pricing and Royalties

1. Are there any royalty payments or other fees?

There is no royalty for research use only. For any revenue generating activities (commercialization of an iPSC- or MSC-derived product or fee for services) please contact REPROCELL at

E. Glossary

  1. BM = Bone Marrow
  2. cGMP = current Good Manufacturing Practice
  3. CFR = Code of Federal Regulations (US)
  4. EMA = European Medicines Agency
  5. FDA = Food and Drug Administration (US)
  6. HIPPA = Health Insurance Portability and Accountability Act (US)
  7. iPSC= Induced pluripotent stem cells
  8. IRB = Institutional Review Board
  9. MCB = Master Cell Bank
  10. MSC = Mesenchymal Stem Cells
  11. QC = Quality Control
  12. WHO = World Health Organization