Abstract
Microreactors are valued for efficient mixing and precise control in nanoparticle synthesis. However, when encapsulating sensitive proteins and enzymes, conventional fluidic shear causes serious damage and activity loss. Critically, the interplay between mixing performance and shear effects within microreactors remains poorly understood, yet is pivotal for the successful preparation of protein-based nanoparticles. This study applied a gas-liquid slug-flow microchannel to synthesize protein nanostructures and enzyme nanocapsules, compared to the single-phase flow microchannel, microstructured continuous stirred-tank reactor (micro-CSTR), and batch reactor. Mixing, residence time distribution, and shear effects in these reactors were examined via experiments and computational fluid dynamics (CFD) simulations, linking them to the properties of prepared protein nanoparticles. Results show that the slug-flow microchannel provides efficient mixing, narrow residence time distribution, and suitable shear. This combination offers significant advantages for the uniformity of particle size distribution, drug release, enzyme activity, and stability in both the thermodynamically driven self-assembly of nanoparticles and kinetically driven synthesis of nanocapsules. Specifically, for catalase nanocapsules, this strategy achieved a low PDI of 0.165 (vs. 0.3-0.5 in references) and a productivity of 4 g·day-1, equivalent to 100 lab-scale batch reactors. This demonstrates the strategy’s strong potential for industrial-scale production and biomedical application of precious protein nanoparticles.
Data availability
The datasets analyzed and generated during the current study are included in the paper and its Supplementary Information and Supplementary Data, which can be obtained from the corresponding authors upon request.
References
Cohen, A. A. et al. Mosaic nanoparticles elicit cross-reactive immune responses to zoonotic coronaviruses in mice. Science 371, 735–741 (2021).
Fu, D. et al. Self-assembling nanoparticle engineered from the ferritinophagy complex as a rabies virus vaccine candidate. Nat. Commun. 15, 8601 (2024).
Liu, Y. et al. Targeted protein degradation via cellular trafficking of nanoparticles. Nat. Nanotechnol. 20, 296–302 (2025).
Duan, L. et al. Nanoparticle Delivery of CRISPR/Cas9 for Genome Editing. Front. Genet. 12, 673286 (2021).
Yang, Z. et al. Self-assembly of biocompatible core-shell nanocapsules with tunable surface functionality by microfluidics for enhanced drug delivery. Adv. Funct. Mater. 34, 2407112 (2024).
Li, H. et al. Self-assembly of peptide nanocapsules by a solvent concentration gradient. Nat. Nanotechnol. 19, 1141–1149 (2024).
Singh, Y. et al. Nanoemulsion: Concepts, development and applications in drug delivery. J. Control. Release 252, 28–49 (2017).
Zhang, X. et al. Nanocapsules of therapeutic proteins with enhanced stability and long blood circulation for hyperuricemia management. J. Control. Release 255, 54–61 (2017).
Qin, M. et al. Catalase-based therapeutics: an antioxidant enzyme therapeutic for COVID-19. Adv. Mater. 32, 2070321 (2020).
Zhang, X., Chen, W., Zhu, X. & Lu, Y. Encapsulating therapeutic proteins with polyzwitterions for lower macrophage nonspecific uptake and longer circulation time. ACS Appl. Mater. Interfaces 9, 7972–7978 (2017).
Gimondi, S., Ferreira, H., Reis, R. L. & Neves, N. M. Microfluidic devices: a tool for nanoparticle synthesis and performance evaluation. ACS Nano 17, 14205–14228 (2023).
Mehraji, S. & DeVoe, D. L. Microfluidic synthesis of lipid-based nanoparticles for drug delivery: recent advances and opportunities. Lab Chip 24, 1154–1174 (2024).
Bezelya, A., Küçüktürkmen, B. & Bozkır, A. Microfluidic devices for precision nanoparticle production. Micro 3, 822–866 (2023).
Xie, M., Viviani, M. & Fussenegger, M. Engineering precision therapies: lessons and motivations from the clinic. Synth. Biol. 6, ysaa024 (2021).
Geng, Y., Ling, S., Huang, J. & Xu, J. Multiphase microfluidics: fundamentals, fabrication, and functions. Small 16, 1906357 (2020).
Kaplaneris, N. et al. Photocatalytic functionalization of dehydroalanine-derived peptides in batch and flow. Angew. Chem. Int. Ed. 63, e202403271 (2024).
Buglioni, L., Raymenants, F., Slattery, A., Zondag, S. D. A. & Noël, T. Technological innovations in photochemistry for organic synthesis: flow chemistry, high-throughput experimentation, scale-up, and photoelectrochemistry. Chem. Rev. 122, 2752–2906 (2022).
Pilkington, C. P., Gispert, I., Chui, S. Y., Seddon, J. M. & Elani, Y. Engineering a nanoscale liposome-in-liposome for in situ biochemical synthesis and multi-stage release. Nat. Chem. 16, 1612–1620 (2024).
Kim, D., Lee, H.-J., Shimizu, Y., Yoshida, J. -i & Kim, H. Direct C–H metallation of tetrahydrofuran and application in flow. Nat. Synth. 1, 558–564 (2022).
Kim, H. et al. Submillisecond organic synthesis: Outpacing Fries rearrangement through microfluidic rapid mixing. Science 352, 691–694 (2016).
Capaldo, L., Wen, Z. & Noël, T. A field guide to flow chemistry for synthetic organic chemists. Chem. Sci. 14, 4230–4247 (2023).
Chen, D. et al. Controlled preparation of lipid nanoparticles in microreactors: Mixing time, morphology and mRNA delivery. Chem. Eng. J. 505, 159318 (2025).
Su, Y., Chen, G. & Yuan, Q. Influence of hydrodynamics on liquid mixing during Taylor flow in a microchannel. AIChE J. 58, 1660–1670 (2012).
Mo, Y. & Jensen, K. F. A miniature CSTR cascade for continuous flow of reactions containing solids. React. Chem. Eng. 1, 501–507 (2016).
Pomberger, A. et al. A Continuous Stirred-Tank Reactor (CSTR) cascade for handling solid-containing photochemical reactions. Org. Process Res. Dev. 23, 2699–2706 (2019).
Liu, Z. et al. Microstructure and ferroelectric properties of high-entropy perovskite oxides with A-site disorder. Ceram. Int. 47, 33039–33046 (2021).
Schuurmans, J. H. A. et al. Interaction of light with gas–liquid interfaces: influence on photon absorption in continuous-flow photoreactors. React. Chem. Eng. 10, 790–799 (2025).
Laporte, A. A. H., Masson, T. M., Zondag, S. D. A. & Noël, T. Multiphasic continuous-flow reactors for handling gaseous reagents in organic synthesis: enhancing efficiency and safety in chemical processes. Angew. Chem. Int. Ed. 63, e202316108 (2024).
Song, H. & Ismagilov, R. F. Millisecond kinetics on a microfluidic chip using nanoliters of reagents. J. Am. Chem. Soc. 125, 14613–14619 (2003).
Zheng, B., Tice, J. D., Roach, L. S. & Ismagilov, R. F. A droplet-based, composite PDMS/Glass capillary microfluidic system for evaluating protein crystallization conditions by microbatch and vapor-diffusion methods with on-chip X-ray diffraction. Angew. Chem. Int. Ed. 43, 2508–2511 (2004).
Khan, S. A. & Jensen, K. F. Microfluidic synthesis of titania shells on colloidal silica. Adv. Mater. 19, 2556–2560 (2007).
Song, Y., Shang, M., Li, J. & Su, Y. Continuous and controllable synthesis of MnO2/PPy composites with core–shell structures for supercapacitors. Chem. Eng. J. 405, 127059 (2021).
Wang, Z. et al. A study of online monitoring for two-phase flow patterns in a microchannel based on deep learning. AIChE J. 71, e18785 (2025).
Panariello, L., Mazzei, L. & Gavriilidis, A. Modelling the synthesis of nanoparticles in continuous microreactors: The role of diffusion and residence time distribution on nanoparticle characteristics. Chem. Eng. J. 350, 1144–1154 (2018).
Gkogkos, G. et al. A compact 3D printed magnetically stirred tank reactor cascade coupled with a free impinging jet for continuous production of colloidal nanoparticles. Chem. Eng. Sci. 294, 120081 (2024).
Alvarado Galindo, F., Venzmer, J., Prévost, S., Hoffmann, I. & Gradzielski, M. Incorporation of short-chain alcohols into fluid bilayers and its effect on membrane dynamic properties as seen by neutron scattering. Colloids Surf. A: Physicochem. Eng. Asp. 702, 135014 (2024).
Sheldon, R. A. Enzyme immobilization: the quest for optimum performance. Adv. Synth. Catal. 349, 1289–1307 (2007).
Jia, Y., Cocker, C. & Sampath, J. Insights into protein unfolding under ph, temperature, and shear using molecular dynamics simulations. Biomacromolecules 26, 2095–2105 (2025).
van Haaren, C., Byrne, B. & Kazarian, S. G. Study of monoclonal antibody aggregation at the air–liquid interface under flow by ATR-FTIR spectroscopic imaging. Langmuir 40, 5858–5868 (2024).
Forsythe, N. L. et al. Noncovalent enzyme nanogels via a photocleavable linkage. Macromolecules 55, 9925–9933 (2022).
Molla, M. R. et al. Unlocking a caged lysosomal protein from a polymeric nanogel with a pH Trigger. Biomacromolecules 15, 4046–4053 (2014).
Villermaux, J. & Falk, L. A generalized mixing model for initial contacting of reactive fluids. Chem. Eng. Sci. 49, 5127–5140 (1994).
Chen, P. et al. Prediction of Taylor flow in microchannels based on generative artificial intelligence. AIChE J. 72, e70181 (2026).
Acknowledgements
The authors thank the staff from BL17B beamlines of the National Facility for Protein Science in Shanghai (NFPS) at the Shanghai Synchrotron Radiation Facility, for assistance during data collection. We are grateful for the discussion about the SEM analysis with Ms. Yuanxin Lin in the Instrumental Analysis Center of Shanghai Jiao Tong University. This work was financially supported by the National Natural Science Foundation of China (Grants 22578266, 22378258, and 22178215).
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Y.S. formulated and supervised the project. Y.S., T.N., and X.J. conceived of the idea. Z.G., Y.Z., and A.T. contributed equally to this work. Z.G., Y.Z., and A.T. conducted the preparation experiments. Y.Z. and A.T. characterized the nanoparticles. Z.G. and Y.M. performed the simulation. Z.G., Y.M., G.Q., and Z.W. performed the micromixing and the residence time distribution experiments. S.L., M.Q., J.S., and M.S. helped with the manuscript discussion. Z.G., Y.Z., A.T., P.C., X.J., and Y.S. wrote and revised the manuscript. All authors were involved in the data analyses and manuscript preparation.
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Gao, Z., Zhang, Y., Tan, A. et al. Slug-flow microchannel enables efficient and controllable preparation of sensitive protein nanoparticles. Commun Chem (2026). https://doi.org/10.1038/s42004-026-02026-2
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DOI: https://doi.org/10.1038/s42004-026-02026-2
