Document Type

Article

Publication Date

4-24-2026

Department

Department of Chemical Engineering; Department of Biological Sciences

Abstract

Scalable, continuous biomanufacturing processes have grown in importance to meet demand for smaller bioreactor sizes, lowered production costs, and improved quality attribute consistency. The Sf9/recombinant baculovirus (rBV) expression system demonstrates promise for virus-like particle (VLP) vaccine and gene therapy production. Here, we present a continuous rBV platform integrating an infection plug flow reactor (PFR) between stirred tank growth (gCSTR) and production (pCSTR) bioreactors. Cell expansion in the gCSTR included a ramp-up stage followed by continuous growth, reaching a steady state of 5×10 cells/mL and >90% viability. Péclet number-fit tracer studies confirmed near-ideal plug flow in the PFR, yielding a 10 h residence time and progressive infection as measured by gp64 signaling. Finally, a pCSTR with a residence time of 48 h exhibited sustained recombinant protein production. An integrated pilot cascade incorporating all reactors ran continuously for 5 days, maintaining stable CSTR cell densities and a measurable increase in infected cell diameter from 14.5 μm to 16.1 μm. Western blotting and EM of ~ 100 nm VLPs in pCSTR effluent demonstrated platform success. Digital twin mechanistic models across four distinct stages of bioreactor operation and Hill-type relationships for rBV infection kinetics predicted cell growth and death for a 7-day run, demonstrating promise for designing continuous systems in silico and building a quantitative framework for scale-up and optimization. Our multi-stage reactor configuration represents a cell host- and product-agnostic production scheme, particularly for processes prone to product heterogeneity, and paves the way towards a true end-to-end continuous platform for myriad modalities in the future.

Publisher's Statement

© The Author(s) 2026. Publisher’s version of record: https://doi.org/10.1186/s13036-026-00680-7

Publication Title

Journal of biological engineering

Version

Publisher's PDF

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