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

Abstract

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.

Keywords: Automation; CBHP, cell-based health care product; Cell processing facility; Decontamination; Manufacturing; Regenerative medicine; fMP, flexible Modular Platform.

Graphical abstract

Fig. 1

Schema of ‘flexible Modular Platform (fMP)’. The fMP system comprises four categories of modules: Processing, Transfer, Load/unload and Incubation modules. Each process, except for the cell culture process, is conducted in a combination of multiple modules. Cell culture processes are conducted by incubation modules only, apart from the Transfer Modules or other processing modules releasing them for other processes.

Fig. 2

Overview of the Tissue Factory. A total of nine modules and a manual operation isolator were built for the Tissue Factory. Each module conducts a relatively simple function but combining multiple modules via the Transfer Module enables a wide variety of cell culture processes. All modules docked to the Transfer Module are controlled from the Control Panel.

Fig. 3

Inter-module connection interface. (1) Article transfer doors. (2) H₂O₂ Injection port to decontaminate the interface. (3) Electrical couplings. (4) Gas connections. (5) Docking guides. (6) Clamping bars. (7) Inflation sealing. (8) Door-combining socket. (9) Sealing. (10) Door-combining pin. (11) Manual clamp. (12) Non-contact power coupling (supplier). (13) Non-contact power coupling (receiver).

Fig. 4

Culture processes in Tissue Factory. In the Tissue Factory, multiple modules cooperatively perform a culture process. Each module can be attached and detached according to the requirements. Materials are prepared in the Material Preparation Isolator (M10) and carried to the Tissue Factory using the Material Loading Module (M6) (A). The other processes are performed in the Tissue Factory (B–E). The Large Scale Culture Module (M9) conducts culture processes apart from the Transfer Module (M1). Module is indicated by the symbols in Table 1.

Fig. 5

Multi-layered myoblast sheets. Five-layer myoblast sheets were manufactured by the Tissue Factory. A) A swine five-layer myoblast sheet adhered on a temperature-responsive culture dish. B) A swine five-layer myoblast sheet detached from the temperature-responsive culture dish by reducing the temperature. C) A cross-sectional view of a human five-layer myoblast sheet obtained by a confocal microscope. Cell sheets stained by three different fluorescent dyes before stacking.

Fig. 6

Growth rates of human chondrocytes. Three independent strains of human articular chondrocytes were passaged both manually and by the Tissue Factory. Growth rates were calculated from seeding densities and harvested cell numbers for each passage. Passage numbers are indicated as additional passage times in the experiment.

Fig. 7

Culture results of human iPS cells. Human induced pluripotent stem cells (hiPSCs) were passaged both manually and by the Tissue Factory. hiPSCs cultured by the Tissue Factory showed comparable growth ratios and characteristics to hiPSCs cultured manually. A) Microscopic view of hiPSCs passaged manually. B) Microscopic view of hiPSCs passaged in the Tissue Factory. C) Growth rates through three successive passages. D) Live cell ratios measured using Trypan Blue dye. E) Flow cytometric analysis of hiPSCs after three passages by stage specific embryonic antigen 4 (SSEA4) and rBC2LCN lectin. Outlined histograms shows isotype control and no-dye control in SSEA4 and rBC2LCN, respectively. Filled histograms show the measured data. Horizontal axes indicate the fluorescent intensities of fluorescein isothiocyanate (FITC) conjugated with SSEA4 and rBC2LCN. Vertical axes indicate cell numbers at each intensity. Percentages of positive (undifferentiated) cells are annotated by the thresholds where the control samples were measured as 0.5%.