Manabu Mizutani

Effects of residual H2O2 on the growth of MSCs after decontamination

Introduction Regenerative therapy is a developing field in medicine. In the production of cell products for these therapies, hygienic management is even more critical than in the production of a chemical drug. At the same time, however, care is required with the use of decontamination agents, considering their effects on cell viability and characteristics. To date, hydrogen peroxide (H2O2) is most widely used for decontamination in pharmaceutical plants and cell processing facilities. Methods In this study, we examined the effects of residual H2O2 in the atmosphere of cell processing units after decontamination on the viability and proliferation of mesenchymal stem cells derived from human bone marrow. Results We detected residual H2O2 sufficient to affect cell proliferation and survival even more than 30 h after decontamination ended. Our results suggest a longer time period is required before starting operations after decontamination and that the operating time should be as short as possible. Conclusions Here we show the effects of post-decontamination residual H2O2 on the viability and proliferation of mesenchymal stem cells derived from human bone marrow, which may provide us with important information about the hygienic management of cell processing facilities.

A novel, flexible and automated manufacturing facility for cell-based health care products: Tissue Factory

Introduction Current production facilities for Cell-Based Health care Products (CBHPs), also referred as Advanced-Therapy Medicinal Products or Regenerative Medicine Products, are still dependent on manual work performed by skilled workers. A more robust, safer and efficient manufacturing system will be necessary to meet the expected expansion of this industrial field in the future. Thus, the ‘flexible Modular Platform (fMP)’ was newly designed to be a true “factory” utilizing the state-of-the-art technology to replace conventional “laboratory-like” manufacturing methods. Then, we built the Tissue Factory as the first actual entity of the fMP. Methods The Tissue Factory was designed based on the fMP in which several automated modules are combined to perform various culture processes. Each module has a biologically sealed chamber that can be decontaminated by hydrogen peroxide. The asepticity of the processing environment was tested according to a pharmaceutical sterility method. Then, three procedures, production of multi-layered skeletal myoblast sheets, expansion of human articular chondrocytes and passage culture of human induced pluripotent stem cells, were conducted by the system to confirm its ability to manufacture CHBPs. Results Falling or adhered microorganisms were not detected either just after decontamination or during the cell culture processes. In cell culture tests, multi-layered skeletal myoblast sheets were successfully manufactured using the method optimized for automatic processing. In addition, human articular chondrocytes and human induced-pluripotent stem cells could be propagated through three passages by the system at a yield comparable to manual operations. Conclusions The Tissue Factory, based on the fMP, successfully reproduced three tentative manufacturing processes of CBHPs without any microbial contamination. The platform will improve the manufacturability in terms of lower production cost, improved quality variance and reduced contamination risks. Moreover, its flexibility has the potential to adapt to the modern challenges in the business environment including employment issues, low operational rates, and relocation of facilities. The fMP is expected to become the standard design basis of future manufacturing facilities for CBHPs.

Experience of contamination during autologous cell manufacturing in cell processing facility under the Japanese Medical Practitioners Act and the Medical Care Act

Cell therapy and regenerative medicine technologies require strict cell manufacturing procedures to be defined and addressed. Maintenance of the aseptic environment is critical to preclude extrinsic contamination risks, similar to conventional pharmaceutical manufacturing. However, intrinsic contamination risks exist in all cell manufacturing processes owing to the use of cells as the raw materials that cannot be sterilized, thus giving rise to the primary and secondary risks of cell contamination and cross-contamination, respectively. Analysis of contamination risks was conducted on experienced batches (29,858 batches) for the production of immune cells derived from autologous blood mononuclear cells under the Medical Practitioners Act and the Medical Care Act in Japan. From these batches, 0.06% (18 cases) of contamination occurred, representing low probability of contamination incidence during cell processing. Almost all the causes of these contaminations were regarded to be from the collected blood (intrinsic contamination), and subsequent cross-contaminations were prevented, considering that the secondary contamination risk can be reduced by adequate managements of operational procedures for changeover in aseptic environment.