FAQ & Troubleshooting

The major advantage of the VW Bioreactor over existing systems is the broad scalability that it can offer, from the R&D and bench-top scale to cGMP production scale.  Since all of our bioreactors use the same mixing mechanism, a bench-top unit can be used as a representative scale-down model during early-stage process development, as well as process characterization for the large scale bioreactors.  In addition, the power input (from the buoyancy of gas) dissipated over a larger mixing device creates more uniform and gentle fluid motion, which provides a lower shear environment even at large scale (estimated by CFD analysis using ANSYS Fluent and STAR-CCM+® software).  This technology has the potential to accelerate time to market by virtually eliminating the potential technology transfer challenges that are often encountered as a process moves from R&D phase to clinical and commercial phases.  Finally, the  VW-Wheel bioreactors have the smallest comparative footprint and are the easy to install and use.

The temperature of the culture is measured non-invasively by resistive temperature detectors (RTD) on the non-disposable housing unit.  Once the vessel/bag has been installed, the RTD on the housing comes in direct contact with the back portion of the vessel/bag and is sufficiently insulated from the conductive metal housing to ensure that it accurately measures the temperature of the vessel/bag.  The temperature of the culture can be maintained at a set point using the automatic mode of our temperature control.  Heat is applied to the vessel/bag as needed using heating pads placed along the bottom curvature of the housing.

‍

‍

All VW systems larger than PBS MINI will come equipped with pH and DO control capabilities, with redundancies in measurements for PBS 80.  There is an option to use reusable sensors or single-use sensors depending on customer's request.  PBS MINI will not have active pH and DO control on the system, so it must rely on controls provided by the carbon dioxide incubator in which it will be housed.

‍

A gas mixture, comprised of varying composition of air, carbon dioxide, and nitrogen (if applicable), is entered or in the headspace of the vessel/bag as overlay. The exact composition will be dictated either by the user or by the automatic pH and dissolved oxygen (DO) controls.  Pure oxygen is supplemented into the vessel/bag as needed to maintain high viable cell densities during the late stage of a production cell culture process. Oxygen mass transfer rates (kLa) of up to 20 hr⁻¹ are possible using our microsparger elements.

‍

Yes, the disposable VW-Wheel impeller is integral to our bag design as it drives the motion of the fluid inside the vessel/bag.  The vertically-oriented wheel rotates freely about a shaft that is anchored to the vessel/bag.  All parts that come in contact with the product are made out of USP Class VI materials and disposable.

‍

We have performed biological testing in the VW Bioreactor in parallel with other bioreactor systems to compare the culture growth, productivity, and product quality.  In addition, fluid dynamics studies have been performed at various scales to quantify mixing time and volumetric mass transfer rate (kLa).  The fluid mixing pattern, shear stress levels, and turbulent kinetic energy dissipation rates have also been investigated using computational fluid dynamics (CFD) modeling on both ANSYS Fluent and STAR-CCM+® software.

‍

The  VW Bioreactor System only requires electricity and compressed gasses.  The bioreactors are designed to run with four gases -  air, nitrogen, oxygen and carbon dioxide - but they can also run without nitrogen.  The bioreactors are designed to connect to your Ethernet network for remote monitoring and control over the World Wide Web.

‍

Our bioreactors have been designed for plug & play simplicity with our integrated software, so they are very easy to use.  As the VW Bioreactors come completely pre-configured, one only needs to plug it into an electrical outlet, connect gas supplies, and turn it on.  Some of our customers have taken delivery of VW Bioreactors in the morning and inoculated them by the same afternoon.

‍

All functions performed by the Hello UI can be performed on a DCS by configuring it to use HTTPS web calls. Contact app.eng@pbsbiotech.com for more details.

‍

The 3L VW Bioreactor is qualified to meet cGMP requirements for product contact materials suitable for clinical trials in humans, as well as 21 CFR Part 11 software requirements. The other VW bioreactors are currently in the process of being tested for cGMP compliance, including all components of single-use vessels, hardware, and software.  All materials used in our vessel/bag that could potentially contact the drug substance conform to USP Class VI and ISO 10993 standards.

‍

Extractables testing will be performed on our single-use vessels in accordance with recommendations from the Bio-Process Systems Alliance (BPSA) and BioPhorum Operations Group (BPOG).  Our test approach will be reviewed by consultants specializing in single-use bag validation, and the testing will be performed by a highly reputable contract laboratory specializing in extractables testing.

‍

The VW Bioreactor System is a completely closed system and can handle high containment requirement applications as well as cGMP operations.  The low shear environment in the VW Bioreactor can potentially expedite and improve virus and vaccine production.

‍

PBS Biotech can work with you to validate our systems in your facility.  We will provide you with a comprehensive validation-ready package to assist you in your validation effort.

‍

Absolutely no cleaning is required, as each single-use vessel/bag is delivered clean and sterilized by gamma radiation prior to shipment to the customer.  The stainless- steel housing is never in contact with process fluids and can be wiped down just like any piece of laboratory equipment.

‍

Thanks to the unique design of the VW impeller, the mixing characteristics of the VW Bioreactors are very homogeneous across all scales.  This includes mixing time, average shear rate, and turbulent energy dissipation rates.  This homogeneity greatly facilitates process scale-up from small development volumes to full production volumes.

‍

Both internal testing and collaborations have shown that VW bioreactors are capable of supporting viable cell densities exceeding 3×10⁶ cells/mL (iPSCs) and 2×10⁶ cells/mL (MSCs). Other tests have shown comparable cell growth performance and productivity between the VW Bioreactor System and other systems currently on the market, which include both traditional stainless-steel tanks and other single-use systems.

‍

All VW Bioreactor vessels/bags contain a novel, vertically-oriented impeller with internal bi-directional vanes that rotates via magnetic coupling around a fixed shaft to create a gentle, three-dimensional liquid flow pattern.

‍

PSCs grown as aggregates, MSCs grown on microcarriers, and MSC-derived exosomes

‍

Yes on case-by-case basis that does not require significant structural alterations

‍

No; for repeat customers, we would only typically quote the BQ- 005 bioreactor config sheet and the execution service, since can use same IQ/OQ protocols from the first time

‍

No, IQ/OQ services are not included but sold separately; clients typically purchase due to PBS being qualified vendor with good system understanding, training on IQ/OQ protocol execution, and specialized calibrated tools that meet the required specs.

‍

In-person travel as primary option, remote also available

‍

Varies by amount of process development required but typically 4-6 months

‍

For biological cell culture questions, please contact our BioLab team. For bioreactor hardware-related questions, please contact our Applications Engineering team.

‍

No, the 80L bioreactor is intended to be placed on a lab floor. Included wheels facilitate movement.

‍

You can customize how often and what kind of data will be stored on the bioreactor’s hard drive (typical storage size of X GB). Automatic downloading of data as a CSV file will go to local computer with direct LAN connection. All user login, changes, and data histories follow 21 CFR Part 11 requirements.

‍

Yes, through a secure web-based connection to a remote

computer, tablet, or phone.

‍

The 80L bioreactor’s software allows for customizable programming of process controls and real-time monitoring of parameters using various sensors. Feedback loops can be used to pause a run based on deviations from a set range with remote alarm notification.

‍

The AHHV can be used for rapid medium exchange: after pausing impeller agitation and letting cells settle to the bottom of single- use vessel, the AHHV extends from the bioreactor housing through a port at the bottom of vessel until it just rises above the cell bed like a periscope. At that point a port opens which draws all the spent medium just above the settled cells. The AHHV can also be used for directly drawing a representative sample of cells or complete harvesting, even while gentle agitation continues.

‍

For biological cell culture questions, please contact our BioLab team. For bioreactor hardware-related questions, please contact our Applications Engineering team.

‍

No, the 15L bioreactor is intended to be placed on a lab floor. Included wheels facilitate movement.

‍

You can customize how often and what kind of data will be stored on the bioreactor’s hard drive (typical storage size of X GB). Automatic downloading of data as a CSV file will go to local computer with direct LAN connection. All user login, changes, and data histories follow 21 CFR Part 11 requirements.

‍

Yes, through a secure web-based connection to a remote computer, tablet, or phone.

‍

The 15L bioreactor’s software allows for customizable programming of process controls and real-time monitoring of parameters using various sensors. Feedback loops can be used to pause a run based on deviations from a set range with remote alarm notification.

‍

The AHHV can be used for rapid medium exchange: after pausing impeller agitation and letting cells settle to the bottom of single- use vessel, the AHHV extends from the bioreactor housing through a port at the bottom of vessel until it just rises above the cell bed like a periscope. At that point a port opens which draws all the spent medium just above the settled cells. The AHHV can also be used for directly drawing a representative sample of cells or complete harvesting, even while gentle agitation continues.

‍

For biological cell culture questions, please contact our BioLab team. For bioreactor hardware-related questions, please contact our Applications Engineering team.

‍

Yes, the housing’s compact footprint is designed to sit atop standard lab benches or push carts.

‍

You can customize how often and what kind of data will be stored on the bioreactor’s hard drive (typical storage size of X GB). Automatic downloading of data as a CSV file will go to local computer with direct LAN connection. All user login, changes, and data histories follow 21 CFR Part 11 requirements.

‍

Yes, through a secure web-based connection to a remote computer, tablet, or phone.

‍

The 3L bioreactor’s software allows for customizable programming of process controls and real-time monitoring of parameters using various sensors. Feedback loops can be used to pause a run based on deviations from a set range with remote alarm notification.

‍

A representative sample of cells and complete harvesting are achieved through sterile tubing lines aseptically connected to vessel. Automated peristaltic pumps and hand-draw options are both available. Note: there is no adjustable height harvest valve (AHHV) available in the 3L bioreactor.

‍

For biological cell culture questions, please contact our BioLab team. For bioreactor hardware-related questions, please contact our Applications Engineering team.

‍

Each Mini base unit has a cable ending in a female adapter that plugs into a DC power adapter unit, which in turn can be plugged into a wall outlet. The power accessory cable can accommodate up to four female adapters from four different Mini bases and consolidate all four into a single DC power adapter with single outlet plug.

‍

We do not recommend reusing vessels due to the risk of contamination from previous cell cultures or washing chemicals.

‍

While everyone’s cell culture process will have different requirements and vessel usage cycles, we recommend keeping at least two weeks' worth of vessels in stock. Please contact our BioLab team if you would like assistance in determining your typical usage of vessels.

‍

Most VW Bioreactors use single-use bags made of polyvinylidene fluoride (PVDF). The PBS 3 and PBS MINI use rigid plastic vessels that are made of polycarbonate.

The VW Bioreactor System consists of two main components: a single-use vessel/bag where cells are grown and the product is produced, and the non- disposable unit that integrates with the single-use vessel/bag.  The single-use disposable vessels and bags are available in sizes from 0.1 L to 80L working volumes.  They are sterilized by gamma radiation and shipped ready-to-use.  Each vessel/bag includes all components that are necessary for promoting cell growth, and all product-contact surfaces are made out of USP Class VI certified materials.

PBS Biotech's Vertical-Wheel (VW) Single-Use Bioreactor System has been designed for cell therapy (stem cell) processes in batch, fed-batch, and perfusion modes.

‍

Yes, we have helped clients in R&D, process development/optimization, and even clinical trial stage including first-in-human studies

‍

• Seed expansion from a working cell bank and serial passaging
• Aggregate-based processes including seeding, expansion, differentiation, dissociation, and harvesting
• Microcarrier-based processes including seeding, expansion, detachment, and harvesting
• Rapid medium exchange techniques
• Cell separation, washing, and concentration

PSCs grown as aggregates, MSCs grown on microcarriers, and MSC-derived exosomes

‍

Is there any difference in performance between reusable and single- use sensors?

‍

What is the difference between floorless and floored VW impellers?

‍

Any cell therapy application that is ready to be scaled up from 15L for clinical studies or commercial-level production.

‍

There is no significant difference in sensitivity and functionality, based on internal testing and product quality assurances from third party providers of reusable (Broadley-James) and single-use (Hamilton).

‍

The floorless and floored impellers are nearly identical in construction, but the latter has more panels around the circumference of the impeller. [image here] The floorless model is recommended for culturing cell aggregates while floorless is recommended for microcarriers with attached cells, due to slight variations in hydrodynamic conditions.

‍

Any cell therapy application that is ready to be scaled up from 3L for clinical studies or commercial-level production.

‍

There is no significant difference in sensitivity and functionality, based on internal testing and product quality assurances from third party providers of reusable (Broadley-James) and single-use (Hamilton).

‍

The floorless and floored impellers are nearly identical in construction, but the latter has more panels around the circumference of the impeller. [image here] The floorless model is recommended for culturing cell aggregates while floorless is recommended for microcarriers with attached cells, due to slight variations in hydrodynamic conditions.

‍

Any cell therapy application suitable at benchtop working volume, or early stage clinical studies including first-in-human trials. The 3L bioreactor is intended to further optimize processes originally developed in PBS Minis.

‍

We recommend handling any Mini vessel inside a biosafety hood for procedures such as unscrewing an orange cap and pipetting in/out of the vessel. A Mini base can be used inside the hood to securely hold the vessel in place, rather than risking a standing vessel being knocked over.

The Mini base and vessel are intended to be placed in an incubator for control of temperature and gases.

‍

Any small working volume cell therapy applications such as process development and optimization.