Advantages of single-use plastic bioreactors in small-scale bioprocessing
Single-use bioreactors (SUBs) offer an unprecedented level of flexibility to researchers and manufacturers. SUBs are made of plastic, and are incinerated after use rather than put through the CIP/SIP cycles required by traditional, stainless steel bioreactors. Advantages of single-use plastic bioreactors are discussed here.
Increased purity and sterility mean more uptime
Single-use vessels come sealed with impellers and spargers already installed. They do not need to be autoclaved before use, and can be installed directly into the outer support container.
Single-use bioreactors are also not subject to in-line sterilization. This saves time while essentially eliminating the risk of cross-contamination between batches. This gives facilities the ability to quickly and easily switch between cell lines and product batches without worrying about purity.
Lower costs are distributed throughout the lifetime
SUBs drastically reduce capital expenditures. Single-use plastic vessels are significantly cheaper than integrated stainless steel or glass vessels. Lifetime operating costs are also much lower than for traditional reactors, even accounting for recurring purchases of disposable components.
Perhaps most impactful, eliminating clean-in-place (CIP) procedures increases the available uptime of the reactor without sacrificing purity. This improves the return on investment for the reactor by greatly improving development and production speed.
Increased flexibility allows for easier experimentation
A single-use bioreactor has a much larger operating range than do multiuse reactors, meaning a single vessel may be appropriate for a large variety of batch sizes. This allows for simpler experimentation and scale-up than was previously available.
Additionally, vessels are no longer subject to the design constraints imposed by stainless steel, making them more innovative and versatile. For example, cubical designs allow for smaller footprints (and saved bench space) while providing natural baffles. The square vessels are easier to protect during packaging and shipping and are simpler to install.
Environmental benefits result from single-use
Quite counterintuitively, SUBs are generally considered to be more environmentally friendly than traditional bioreactors. While SUBs rely on disposable plastics, manufacturing plastics requires significantly less energy than manufacturing stainless steel, accounting for repeated production of the plastic vessels.
Single-use vessels are then disposed of, while multiuse vessels are cleaned. CIP is extremely energy intensive, with wastewater containing harmful acids and detergents that must be neutralized (an additional energy-intensive process). In contrast, single-use components including sensors, tubing, and stirrers are disposed of by incineration, allowing some of the energy to be recovered.
Is this the end of multiuse reactors?
No! Traditional, multiuse bioreactors still outperform SUBs in a few key areas, the most important of which is the ability to deliver at scale. While batch sizes in cGMP production can easily reach 10,000 liters, SUBs batch sizes cannot exceed about 2,000 liters. This makes SUBs optimal through research and pilot phases, but drug producers will still need traditional reactors to meet the production demands of large-scale runs.
That said, SUBs have better sterility, higher product purity, reduced cleaning time, and much lower startup and maintenance costs than traditional bioreactors. Improvements in baffling, impelling, and sparging have all contributed to increasing the maximum batch size and further building out the advantages of single-use plastic bioreactors. In short, SUBs have delivered on their early promises and are rapidly addressing remaining challenges with new developments in reactor technology.