Spotlight on: a production scientist working in a clean room  

Australia is playing a leading role in the area of gene therapies, which show promise in treating everything from infectious and rare diseases to cancer. To ensure that the health system is future-ready for these groundbreaking treatments, the Office for Health and Medical Research has funded local manufacturing capacity in this area and has also developed the Preparation of Pharmaceutical and Advanced Therapeutic Directive in collaboration with the NSW Health Pharmaceutical and Regulatory Unit, which outlines safety and standards for the production of gene therapies.  

Through a range of different funding options including Early-Mid Career Researcher Grants, Gene and Cell Therapy Grants and the Translational Research Grants Scheme, the Office for Health and Medical Research (OHMR) is also supporting clinical trials and research in gene therapy. In 2018 OHMR provided funding to the facility through a Gene and Cell Therapy grant which assisted in the establishment of small scale GMP vector manufacturing for gene and cell therapy clinical trials. 

Special clean rooms must be used to produce these gene therapies and other advanced therapeutic products, to ensure that they are made to the highest standard and are safe for patients. We spoke to Hoda Zarei, a Production Scientist working in the Gene and Cell Medicine Facility based at the Sydney Children’s Hospitals Network, to understand more about what happens in a clean room. There, Hoda produces gene therapy treatments that have the potential to save lives. 

What is a clean room?

A clean room is an enclosed and controlled environment where the air is filtered to maintain a very low concentration of airborne particles such as dust, microbes (tiny microscopic living organisms such as bacteria and viruses) and aerosol particles (that might come from a person coughing). Reducing the number of these particles significantly reduces risk of contamination of the therapeutic product being made in the clean room. There are multiple national and international standards and accreditation that clean rooms must comply with to ensure maximum quality and safety of therapeutic products. The air pressure and air exchange rate have to be highly controlled. The temperature in clean rooms is typically kept between 19 and 20 degrees Celsius and the humidity is kept low to prevent condensation and any risk of mould. All of these factors help to ensure that we can produce gene therapy products that are free from contaminants and are of the highest quality. Clean rooms are monitored continuously with live data that records the air quality and the number and nature of airborne particles in the clean room.  

How is the air filtered?

Clean rooms contain special HEPA (High Efficiency Particulate Air) filters, which are very effective at removing airborne particles of certain sizes. These are similar to the filters used in vacuum cleaners, so that all the dust particles are trapped inside the vacuum and not recirculated into our homes. To help maintain clean air, staff must enter and exit clean rooms through air lock doors and ‘gowning’ areas called ‘anterooms’. Some clean rooms also have air showers which feature a high velocity clean air stream to remove particles from staff before they enter a clean room. Clean rooms have different air pressure to normal rooms. Positive air pressure clean rooms contain a higher level of air than a normal room. This is to avoid airborne microbes from entering the room and potentially contaminating the sensitive products we’re making. Negative pressure clean rooms contain the substances inside the room. They protect staff and the environment from being accidentally exposed to products that may be potentially hazardous, such as chemotherapy agents used to treat cancer. 
 
Why is a clean room needed?

A clean room is necessary and in some cases required by law to protect the therapeutic product being made there from contamination. In the clean room where I work, we produce gene therapies. By ensuring this work space is the cleanest environment with the cleanest air possible, we also ensure that the gene therapy is as safe and effective as possible when administered to the patient. Throughout the many processes of manufacturing in our clean rooms there is also ‘in process sampling’ where a sample is taken and sent to the quality department and they check it for quality and purity to confirm there is no contamination. 

What led you to pursue a career in this field?

After finishing my medical science degree, I gravitated towards this area because I have a significant interest in Biologics and this industry is an area where amazing and rapid advances have been occurring. These advances have allowed scientists to understand the biological pathway of genetic diseases, which in turn enables the development of targeted gene therapies.  

What is gene therapy?

Gene therapy is a cutting-edge treatment that uses parts of DNA to modify a person’s genes in order to treat a disease or chronic health condition. Gene therapy is usually given to a patient by an injection or an infusion – one infusion can be made up of a trillion copies of the viral vector. Once given to the patient, the viral vectors transport the new DNA into their cells. Depending on the purpose of the gene therapy, it can do a number of things. It might replace a defective gene with a healthy copy of the gene. It might inactivate a defective gene that is causing the disease or it might introduce a new or modified gene which can help treat or prevent disease.

How are clean rooms classified?

There are four grades of clean room environments and there are several processes required as you move between the different grade rooms, which get cleaner from Grade D (the lowest level of environmental control) to Grade A, (which has the highest level of control). A Biological Safety Cabinet is also considered Grade A. We have three dedicated clean rooms. One is for upstream processing, which involves cell cultures. A second clean room is for downstream processing, which is a cell-free process that helps to clarify, purify, and concentrate the final product. A third cleanroom is used to perform sterile filling of our manufactured product. This means that we aseptically transfer the purified product into the final containers, such as product vials. These then get placed in a freezer at minus 80 degrees Celsius. That’s the final stage of our manufacturing process and the product is kept frozen when it is transported from the facility. 

What kind of equipment is used?

Some of our clean rooms contain incubators, which are large machines with trays that can accommodate a range of different vessels used to grow and maintain cell cultures in an environment that controls temperature and humidity. Our clean rooms also utilise centrifuge machines which spin vials at high speed. The force then pushes heavier materials to the bottom. For gene therapy, this process helps to separate cells and cell debris from the liquid, which is called the ‘supernatant’. In Grade A clean rooms, a Biological Safety Cabinet is. It is a special work station where critical material can be safely handled in a highly protected aseptic environment. These cabinets have a HEPA air filtration system built in to supply unidirectional filtered air flow over the work surface. Our facility also contains medical grade freezers and a liquid nitrogen tank where the cells are kept in cold storage.  

How many people are allowed in your clean rooms at one time?

According to the Therapeutic Goods Administration (TGA), humans lose around 200,000,000 skin cells per hour, which means they can be a major source of contamination in a clean room. This is why we have facility garments to cover our skin, hair and nails. It is also why we limit the number of people in our clean room at any one time to only two or three people. 

Why do clean room staff learn choreographed ways to move?

The faster you move, the more skin cells you shed, so before working in a clean room I had to undergo extensive training in the correct hand movements when manipulating cell cultures, other materials and gene therapy products, as well as learning other clean room behaviours. In a Grade A and Grade B clean room, every movement I make needs to be very slow and methodical, with economy of movement.  

What protective clothing do you wear? 

When I work in a clean room facility of any grade, make-up, jewellery, and items that are not required for the work to be done are strictly prohibited. Before entering a Grade C clean room, I replace my street clothing with specialised facility gowns and swap my socks for cleanroom socks. I put on a hair net, (beard nets are also available as required) and clean room shoes made from a non-shedding, easy to clean material. I also put on sterile nitrile gloves, which are very durable and resistant to punctures and chemicals. Next, before entering a Grade B clean room, I put on special clean room garments which look like a hazmat suit, which is protective clothing that covers the face as well as the body. This gowning process involves a specific technique where we get dressed in a particular order to avoid touching the outer part of the garment. 

How are materials decontaminated?

To ensure that staff are not introducing any microbes into the clean room, material decontamination is a very important step as I move into rooms of different grades. Decontamination is achieved by wiping down surfaces and wiping down surfaces of the packaging. When I do this, I saturate a low-particle-shedding wipe with the appropriate cleaning agent and I wipe the whole surface area in a unidirectional movement. To ensure I don’t miss any areas, I also overlap the areas that I wipe down. This ensures any microscopic particles will be wiped away from the critical end and lifted off with the wipe. Decontaminated material is passed from the lowest grade clean room to the next grade clean room using special airlock pass-through hatches. 
 
What do clean room verifiers and operators do? 

The operator performs tasks such as ‘aseptic admixing’ in the Biological Safety Cabinet. This process is a little like mixing all the right ingredients needed for a recipe. So, a great deal of attention to detail and accuracy is required for this role. The operator engages in all the hands-on aseptic manipulation from the upstream process to the downstream process.

The verifier is responsible for the activities that occur outside of the Biological Safety Cabinet in the Grade B clean room. They help get the operator all set up with the material and equipment needed and perform the environmental monitoring procedures. The verifier also closely watches what the operator is doing. They check that the measurement of materials is correct. They ensure that the operator is following the steps correctly and that each step has been completed before the operator can move on to the next steps. As a Production Scientist, I do both roles.  
 
What do you enjoy most about your job?

I like working with fragile and sensitive biologics (large complex molecules) and it is very gratifying to know that my job helps play such a crucial role in a patient’s recovery. I also feel extremely privileged to be involved in ground-breaking work which will help save lives in the future.