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Report

Teaser, summary, work performed and final results

Periodic Reporting for period 1 - SUSPENCE (SUSPension ENvironment for CEll culture)

Teaser

Summary

The large-scale production of cells is a mandatory step to set up economically viable in vitro experimental models for basic research, disease modelling and drug testing, and to definitely translate tissue engineering and regenerative medicine strategies to the clinical practice for therapeutic applications. However, scalability and standardization in cellular manufacturing processes are still major challenges. In particular, when large numbers of cells are required, conventional two-dimensional (2D) culture strategies, mainly based on manual, extremely space- and labour-intensive interventions, are practically and financially unsustainable. For these reasons, methods providing a 3D suspension culture environment, mimicking the micro- environment of the cellular niche, have been widely adopted in industrial biotechnology for: (i) scalable and controlled expansion of stem cells and cancer cells; (ii) guiding stem cell differentiation; (iii) production of cellular spheroids and tissue-like constructs. Nowadays, dynamic suspension culture for scalable production and differentiation of cells is mostly performed by stirred tank and rotating bioreactors. Such devices are designed for providing a 3D homogenous culture environment, and for enabling monitoring and control of culture parameters, leading to more reproducible, robust and cost-effective processes. However, most of these bioreactors still suffer from critical issues, limiting the upscaling and the standardization of the expansion bioprocesses. Concerning stirred tank bioreactors, their performance can be affected by (i) collisions of the cells with the impeller and (ii) the onset of turbulent flow, that both can induce non-physiological mechanical and hydrodynamic-shear stresses on the cells and lead to cell damage. Moreover, these unfavourable conditions can affect cell growth rate and metabolism, interfere with stem cell pluripotency, and limit efficiency and reproducibility of the culture process. Rotating bioreactors generate a low-shear stress culture environment, allowing to partially overcome the limitations of stirred tank devices. However, the complexity of the technological solutions adopted for rotation make these devices not easily scalable and unsuitable for continuous medium replacement and real-time monitoring.
Cell culture is a key activity for research centers, biotech companies and hospitals. Several culture methods are applied, the simpler and more widespread being Petri capsules. More advanced methods are based on bioreactors, available in different categories varying in operation principles, size and cell culture application. As anticipated, SUSPENCE belongs to the category of dynamic suspension bioreactors.
Compared to the conventional practices, based on manual cell culture activities subject to high variability and hardly scalable for large scale cell production, dynamic suspension bioreactors offer higher efficiency, security, scalability, process standardization and monitoring.
The key objective of the Phase I project is the development of a detailed Business Plan, including market analysis and commercialization, technical and economic feasibility assessment and plans for product validation, business development, dissemination, contractual and IPR protection framework, commercialization agreements, forecast profit and loss, financial indicators and ROI estimations.

Work performed

The SUSPENCE solution is a microgravity perfusion bioreactor, a highly innovative technological system that keeps cells in suspension in the culture chamber allowing them to grow and reach maturity in dynamic conditions, where nourishment and oxygenation are ensured by medium perfusion. The design of the device (Figure 1 A and Figure 1 B) was driven by two main requirements: (i) to provide dynamic suspension culture with proper mixing; (ii) to guarantee a tunable ultralow-to-moderate shear stress culture environment, adjustable on the basis of culture requirements by simply modifying operating conditions. These objectives were achieved combining the peculiar geometric features of the bioreactor culture chamber with the continuous recirculation of the culture medium ensured by a closed-loop recirculation circuit, avoiding the use of impellers and/or rotational components. This combination promotes the establishment of buoyant vortices within the culture chamber, that maintain cells/constructs in dynamic suspension, minimizing their sedimentation. The closed loop recirculation circuit includes a medium reservoir, a peristaltic pump, and oxygen permeable tubes (Figure 1 C).
Significant benefits have been introduced by the SUSPENCE reactor innovative design features:
- Creation of a microgravity environment in the culture chamber, achieved through the peculiar geometry design, improves cells freedom, their interaction and avoids sedimentation.
- Culture medium perfusion, achieved through the pump, valve and membrane system, enables precise, programmable control of the medium flow and continuous exposure of cells to nutrients.
- Absence of electromechanical parts in the culture chamber, achieved through design innovation, reduces shear-stress on cells, device and maintenance costs, lateral tension and cells damage.
SUSPENCE benefits have been confirmed by explanatory tests carried out on an in vitro cell culture of Non-Small Cell Lung Cancer (NSCLC) cell line Calu-3.
The biological results indicate that this approach preserves cancer cell growth in vitro, including spheroid formation, and suggest the suitability of the proposed bioreactor for investigation on cell functional properties, and for expansion of different cell types.

Final results

Products in this niche are offered by various manufacturers and distributors worldwide, and can be subdivided into three main categories:
- Stirred-tank bioreactors: suspension is generated by mechanical parts movement inside the culture chamber (GE Healthcare, Eppendorf, Pall).
- Wave-mixed bioreactors: suspension is generated by the bioreactor oscillation (GE Healthcare, Sartorius);
- Air-lift bioreactors: suspension is generated by air/gas flows through the culture chamber (Infors HT).
Compared to the conventional practices, based on manual cell culture activities subject to high variability and hardly scalable for large scale cell production, dynamic suspension bioreactors offer higher efficiency, security, scalability, process standardization and monitoring.
There is a clear need and high potential demand for an effective 3D suspension bioreactor representing an advantageous and economically viable alternative to monolayer techniques for large-scale expansion of cells, still applied by the majority of biotech SMEs and research centers. The size of this potential market has been estimated in over 6.000 potential customers on EU level (see Task 2) and more than 50.000 potential customers all over the World, corresponding to a potential market size of 250 Mâ‚¬ per year. BioCom intends to seize this business opportunity by introducing a suspension bioreactor with no rotation mechanism or moving parts. This will enable high-performances cell culture processes at a lesser cost and with less complexity than the current solutions on the market.