FAQ

Exosomes, the nanoparticles secreted from cells, have demonstrated great potential for treating several diseases through intercellular communication of therapeutic factors such as therapeutic miRNAs. Specifically, mesenchymal stem cell–derived exosomes (MSC-Exos) have attracted increasing attention in the pharmaceutical industry.

However, given the rapid growth of exosome-related products in the market, an essential question must be asked: Are the vesicles you are using truly exosomes?

Purification technologies are the foundation  for ensuring exosome quality. Cell culture supernatants comprise  a complex milieu of particles of diverse sizes and functions, including cell debris, proteins, and other nano-sized vesicles. Only through rigorous purification processes can effectively isolated genuine exosomes while preserving their integrity and biological functionality.

In response to these challenges, the International Society for Extracellular Vesicles (ISEV) has published MISEV2023 guidelines, which provide detailed recommendations for exosome purification and characterization, including:

• Implementing multi-step purification workflows
• Selecting purification techniques based on sample characteristics
• Utilizing filtration or chromatography methods to improve purity
• Standardizing and documenting purification procedures with transparency

Despite the most efficient purification methods, obtaining completely pure exosomes in every batch is not guaranteed, which makes the characterization techniques indispensable for confirming whether the purified products are truly exosomes. Recommended practices include:

• Employing multiple complementary analytical techniques for exosome profiling
• Using appropriate controls to validate data accuracy
• Providing comprehensive data output (particle size distribution, quantification of biomarkers, and content analysis)

Only through stringent purification combined with precise characterization can the quality and safety of exosomes be assured. For producing clinical-grade exosomes, it is imperative not only to meet the GMP guidance in producting exosome-related products, but utilize clinical grade cell source as starting material and adopt validated assays to confirm exosome-specific features and functions.

Gwo Xi Stem Cell has developed a proprietary exosome technology platform, featuring GMP-compliant cell banks and manufacturing facilities. We provide comprehensive safety and functional assays to ensure the purity, consistency, and stability of exosome products, fully supporting clients’ CDMO manufacturing needs.

◎ Autologous Stem Cells

Autologous stem cell therapy utilizes stem cells derived from the patient’s own tissues (self-derived). This process requires harvesting tissue (i.e., fatty tissue, bone marrow) from the patient, followed by laboratory preparation, which includes isolation, expansion, quality control, and packaging (typically requiring at least two weeks), before being delivered to the hospitals for the therapeutic application.

GWOXI has developed two autologous stem cell products: GXHPC1^® for the treatment of Liver Cirrhosis in ongoing Phase II; GXNPC1^® for the treatment of Chronic Stroke in ongoing Phase III. Currently, under Taiwan regenerative medicine act, only autologous stem cell therapies are approved for clinical use without license under certain condition, which is limited. Additionally,  autologous cell therapy is “customized,” requiring multiple quality control (QC) steps in cell preparation, which is more costly compared to allogeneic stem cells, but it is generally considered safer than allogeneic stem cells.

◎ Allogeneic Stem Cells

Allogeneic stem cell therapy uses cells derived from a donor (donor-derived). The majority of allogeneic stem cell therapy uses mesenchymal stem cells (MSCs) for therapeutic application. MSCs exhibit very low levels of HLA-DR on their surface, which minimizes the risk of immune rejection when processed under proper manufacturing conditions and rigorous quality control. Consequently, allogeneic MSC therapies have seen increasing used in clinical application, particularly in orthopedic applications such as osteoarthritis.

GWOXI has developed two allogeneic stem cell therapy products: GXCPC1^® for the treatment of osteoarthritis in ongoing Phase III; GXIPC1^® for the treatment of type 1 diabetes in completed Phase I. The key advantages of allogeneic stem cell therapy are off-the-shelf availability and lower cost, which are more accessible to patients. Leveraging cells from qualified-donor working cell bank (WCB), the allogeneic cell therapy products can significantly reduce cost of cell preparation through one quality control within mass production and provide off-the-shelf product for immediate clinical application when needed, thereby offering a more accessible option for patients compared to autologous transplantation.

Good Tissue Practice (GTP)

GTP refers to the regulatory framework established to ensure the safe handling and use of human cells and tissues for a cell processing unit (CPU). To prevent the introduction, transmission, and spread of infectious diseases via human cells and tissues, the Taiwan Ministry of Health and Welfare formally issued the “Good Tissue Practice (GTP)” guidelines on December 13, 2002.

GTP standards assist organizations in ensuring that human cells and tissues are free from infectious agents, remain uncontaminated during processing, and maintain their functional integrity. GTP represents a proactive, risk-based approach, emphasizing meticulous quality control and preventive measures. Compliance with GTP enables cell therapy products to achieve safety, efficacy, and consistent quality.