Biopharmaceutical production has undergone remarkable transformations in recent decades, driven by the growing complexity of therapeutic molecules and the demand for faster, more efficient, and more flexible manufacturing strategies.
While the industry initially focused on monoclonal antibodies (mAbs), numerous emerging therapeutics — including bispecifics, viral vectors, and exosomes — are now reshaping how bioprocess engineers approach design and scale-up.
Mauro Torres, a researcher at the University of Manchester, has worked extensively with cell engineering and process development. His observations provide a detailed view of the current breakthroughs and persistent gaps in using cells as miniature “factories” for complex biologics.
Evolving Needs in Bioprocess Development
A Call for Flexibility
Many large pharmaceutical organizations excel at producing well-established modalities such as mAbs. They often employ streamlined processes honed over the years, delivering consistency and high titers for specific product classes. However, according to Dr. Torres, this same efficiency can become a limiting factor when the pipeline shifts toward novel molecules or advanced therapies.
Manufacturing platforms that work elegantly for standard antibodies may struggle with more complex proteins or new product classes, such as RNA-based drugs or cell therapies. Small and mid-sized contract manufacturing organizations (CMOs) face unique challenges competing against big pharma’s robust infrastructure while staying agile enough to accommodate emerging therapeutic formats.
The Academic-to-Industry Gap
University labs frequently generate promising therapeutic leads, but translating these discoveries into viable clinical products is far from straightforward. Early proof-of-concept work often relies on small-scale benchtop experiments that do not reflect actual manufacturing constraints.
Researchers may not account for critical quality attributes, long-term stability, or regulatory demands that will arise when scaling to pilot or production levels. When a candidate is ready for process optimization, fundamental changes in cell lines or culture conditions may be necessary, potentially setting the program back in time and cost.
Understanding the “Cell Factory” Concept
From Insulin Extraction to Streamlined Platforms
Biopharma’s early years involved extracting hormones (e.g., insulin) from animal tissues, a practice with poor consistency and heightened contamination risks. The shift to manufacturing these substances in host cells dramatically improved safety, quality, and yield.
Over the past 40 years, researchers have built an expansive toolkit of genetically modified cell lines and culture strategies, collectively described as “cell factories.” A cell factory is a living system where each component — from the nucleus encoding genetic information to the endoplasmic reticulum and Golgi apparatus governing protein folding and glycosylation — works in unison to assemble complex biomolecules.
This in-cell assembly line features numerous checkpoints that mirror industrial manufacturing, ensuring that only properly formed products are secreted.
When you go to a car manufacturing company, a car starts from a piece of raw materials that are assembled in a specific way and at the end you have a fully assembled product that can be chipped out. When you manufacture, for instance, a monoplane antibody, you have something very similar. But instead of having a real world factory, you have a cell that they have all the requirements and specific compartments that they comprise a real pipeline.
Key Breakthroughs in Cell Factory Development
- Recombinant Insulin and mAbs: Early success in producing recombinant insulin validated the feasibility of large-scale protein manufacturing with microbial or mammalian cells. This laid the groundwork for using Chinese Hamster Ovary (CHO) cells to make therapeutic antibodies at scale.
- Genetic Engineering of Host Cells: Transposon-based systems and other gene-integration tools have helped developers rapidly stabilize cell lines, streamline expression, and reduce screening overhead.
- High-Throughput Platforms: Microfluidics, single-cell sorting, and advanced robotics significantly accelerate clone selection, removing less productive or unstable lines early.
- Continuous Processing: Companies like Fujifilm Diosynth Biotechnologies have innovated continuous manufacturing approaches, potentially lowering costs and making local “modular” production a realistic option.
Reprogramming CHO Cells for Higher Titers
Learning from Plasma Cells
One of the essential questions in commercial-scale protein production is how to push host cells, most frequently CHO or HEK lines, to secrete more product without harming viability or stability. Nature already provides a potent model through plasma cells.
Mature plasma cells, originating from B-lymphocytes, are highly secretory, producing large volumes of antibodies within a short window. Torres notes that these plasma cells undergo a massive differentiation process: they reorganize subcellular pathways for protein assembly and quality control, then ramp up the machinery required for large-scale antibody secretion.
However, mimicking plasma cells in a manufacturing setting is not trivial. These cells often cease proliferation (they become non-dividing) and eventually “burn out.”
Researchers have identified specific transcription factors and genetic drivers that convert B-cells into robust secretors, but engineering these same pathways in CHO cells can yield lines that lose viability faster, undermining the extended culture runs common in bioreactors.
Consequently, an active area of research involves dissecting the plasma cell shift to find stable modifications that increase titer but preserve CHO cells’ capacity for long culture durations.
Balancing Growth and High Productivity
- Short-Lived vs. Extended Cultures: Plasma cell–like modifications typically produce a surge in secretion at the cost of a limited lifespan.
- Gene Expression Modulation: Introducing certain transcription factors can accelerate protein assembly but may also activate apoptosis pathways, requiring fine-tuned regulation.
- Screening for Viability: High-throughput techniques help identify the subclones that combine boosted secretion with acceptable growth profiles, although generating enough data to characterize these lines remains a persistent challenge.
The Intricate Secretory Pathway
Endoplasmic Reticulum to Golgi
In automotive manufacturing, raw materials undergo assembly line steps, each with strict quality checks before moving on. Torres describes the cell’s endoplasmic reticulum (ER) as the first station for protein assembly: polypeptide chains are folded, glycosylation begins, and only properly structured proteins pass.
The Golgi complex then refines glycan patterns and ensures final quality checks. ER and Golgi compartments handle thousands of potential proteins, each governed by specialized chaperones and transport vesicles. Misfolded or suboptimal proteins may be rerouted for degradation.
Cellular Bottlenecks and Quality Control
- ER Overload: If the incoming translation rate surpasses the ER’s capacity, proteins may misfold or accumulate, triggering the unfolded protein response (UPR) and potentially reducing yields.
- Golgi Refinement: Correct glycosylation is crucial for monoclonal antibodies and other therapeutics. If glycosylation enzymes are downregulated late in culture, product heterogeneity can rise.
- Stress Responses: High-producer clones may face more significant intracellular stress, requiring engineering solutions that boost the protective pathways or expand the secretory apparatus to maintain productivity.
The Power of a Systems-Level Approach
Merging Omics Data with Host Cell Physiology
To fine-tune cellular pathways, researchers leverage multiple “omics” platforms (transcriptomics, proteomics, metabolomics, etc.) to probe how gene expression shifts through various stages of the culture.
Ideally, these datasets reveal specific choke points: if an enzyme enabling glycosylation drops after day 10, scientists might bolster its expression or feed specific precursors to sustain function. While such high-dimensional data can be indispensable for uncovering hidden mechanisms, Torres cautions that not all omics methods are equally mature.
Proteomics and epigenetics, for example, can still pose interpretive and reproducibility hurdles.
Practical Applications for Process Optimization
- Extended Culture Windows: Targeted genetic modifications or feed strategies can stabilize the process if omics show specific stress markers or glycan-processing enzymes diminish in the final days.
- Adaptive Feeding: Real-time metabolic profiling can guide feed composition, ensuring cells receive optimal carbon sources, amino acids, or cofactors at each stage.
- Clone Ranking: Multi-omics data can help identify which clones have robust subcellular machinery early. This pre-selection can dramatically shorten development timelines.
AI, Synthetic Biology, and the Future of Cell Factories
Convergence of Breakthrough Technologies
Torres sees an exciting convergence taking shape. Artificial intelligence (AI) and machine learning (ML) algorithms are opening new ways to handle the vast data streams modern processes generate.
Meanwhile, synthetic biology frameworks allow scientists to embed “genetic circuits” into cells, equipping them with logic gates that sense signals and adjust gene expression accordingly. Combined, these tools may yield lines capable of self-regulating under changing cultural conditions.
AI-Driven Insights
- Data Overload: Major pharma companies now gather exponentially more data each year compared to the previous two decades, raising questions about how to draw actionable insights.
- Pattern Recognition: ML can detect subtle correlations in cell culture data that might otherwise go unnoticed. For instance, feedback loops in oxygen consumption or minor pH shifts might be early stress indicators.
- Predictive Scale-Up: Hybrid models blending mechanistic knowledge with ML can forecast how a process behaves at a large scale without extensive trial-and-error.
Synthetic Biology’s Expanding Toolkit
- Customizable Genetic Switches: Synthetic biology can insert circuits that detect stress or nutrient depletion, triggering corrective responses (e.g., upregulating chaperones or shifting metabolism).
- Circuit Complexity: Much like advanced control engineering, these designs can incorporate multiple layers of feedback. For example, a circuit might sense reactive oxygen species (ROS) and launch an antioxidant gene expression if ROS surpasses a threshold.
- Beyond Antibodies: Synthetic biology also creates possibilities for producing exosomes, viral vectors, and next-generation gene therapies with carefully tuned attributes.
Practical Advice and Key Takeaways
Navigating a Rapidly Changing Landscape
For scientists and engineers seeking to harness or improve cell factories, Torres highlights several considerations:
- Anticipate Variation: Processes that appear seamless for standard antibodies may falter for novel formats like bispecifics, multi-specifics, or viral-based products. Adaptable approaches will be essential.
- Align Lab Scale with Commercial Reality: Early academic or small-scale development should factor in scale-up constraints, from ensuring consistent glycosylation to verifying robust viability at high cell densities.
- Use Multi-Omics with Caution: While transcriptomics and metabolomics have matured, proteomics or epigenomics can still be challenging. The most effective strategies use omics in synergy, focusing on well-validated data layers.
- Combine Automated Screening Tools: Systems like Ambr® (Sartorius), microfluidic sorters, or advanced single-cell systems can help filter out poor performers, drastically reducing development timelines.
- Explore Synthetic Biology: Genetic circuits can provide dynamic control mechanisms inside cells, but building and validating these systems will require cross-disciplinary collaboration among engineers, geneticists, and computational modelers.
Building on 40 Years of Cell Factory Progress
The fundamental concept of a cell factory, a living system engineered to assemble complex, high-value proteins, has propelled the biopharmaceutical industry forward. Improvements in gene integration, advanced clone selection platforms, and continuous manufacturing have multiplied overall productivity. Still, the pipeline is rapidly diversifying, and no single approach can meet the demands of every new therapeutic format.
The future looks very promising and I guess the merging of the different technologies like synthetic biology, artificial intelligence, machine learning, it gives a lot of potential to start thinking about what is the next generation of medicines or the next generation of bioprocess that can be more predictable, making more affordable medicine for patients and technologies that they are highly robust and highly reliable.
Looking Ahead
- Localized Manufacturing: Modular, continuous bioreactors could eventually enable smaller-scale yet high-output facilities near patient populations, improving access and reducing distribution complexities.
- Next-Gen Therapeutics: RNA-based medicines, cell therapies, and exosomes are rising, each posing distinct cell factory and purification challenges.
- Evolving Educational Resources: Increased online platforms and open communication channels between industry and academia are vital. Formal groups like the Bio Industry Association (BIA) or BioPharm International and direct researcher engagement on social media or LinkedIn can rapidly disseminate new best practices.
Conclusion
Cell factories remain at the heart of modern biologics production, offering finely orchestrated systems for building therapies that often cannot be synthesized any other way. The continued emergence of AI-driven analytics, synthetic biology control elements, and advanced bioreactor platforms means the industry has never been better equipped to tackle previously intractable challenges. Nonetheless, developers must remember that reprogramming living cells is as much about understanding each layer of complex intracellular machinery as it is about adding new technology to the process.
Manufacturers can push beyond the conventional monoclonal antibody paradigm by taking a holistic approach, from early gene editing to multi-omics analysis, real-time monitoring, and applying advanced computing methods. They can deliver higher titers, more diverse product formats, and more reliable results.
Bridging academic innovations with industrial realities and harnessing the synergy of computational tools and synthetic biology will likely be the defining factors in shaping the next generation of cell factories. In such an environment, the potential to generate new medicines at lower costs and broader scales is not merely a distant vision but a rapidly approaching reality.opment is digital, and hybrid modeling is at the forefront of this transformation.
About Mauro Torres
Mauro Torres is a chemical engineer and molecular biologist, dedicated to advancing mammalian cell engineering for biomanufacturing. His pioneering research at the University of Manchester aims to create innovative technologies that streamline the development and facilitate the scaling up of biopharmaceutical and advanced therapy production processes.
Connect with Mauro Torres on LinkedIn.
David Brühlmann is a strategic advisor who helps C-level biotech leaders reduce development and manufacturing costs to make life-saving therapies accessible to more patients worldwide.
He is also a biotech technology innovation coach, technology transfer leader, and host of the Smart Biotech Scientist podcast—the go-to podcast for biotech scientists who want to master biopharma CMC development and biomanufacturing.
Hear It From The Horse’s Mouth
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