Due to the complexity of biological processes, developing model-based
strategies for monitoring, optimization and control is nontrivial.
Hybrid neural models, combining mechanistic modeling with artificial
neural networks, have been reported as powerful tools for bioprocess
applications. In this paper, a systematic literature review is presented
focused on the application of hybrid neural models to bioprocesses by
Preferred Reporting Items for Systematic Reviews and Meta-Analyses
(PRISMA) over the last 30 years. This analysis showed that hybrid neural
modeling has covered a wide range of microbial processes, animal cells,
mixed microbial cultures, and enzyme biocatalysis. Hybrid neural models
have been mainly applied for predictive modeling/process analysis,
process monitoring/software sensors, open- and closed-loop control,
batch-to-batch control, model predictive control, intensified design of
experiments, process analytical technology, quality-by-design, and more
recently, digital twins. Hybrid modeling experienced a decline in the
number of publications after a peak in 2004 and is now surging again. A
“model scale” research gap was identified, which will likely narrow by
a better integration with deep learning and systems biology in the near
future. The biopharma sector is currently a major driver but
applications to biologics quality attributes (e.g. glycosylation), new
modalities and downstream unit operations are significant research gaps.