Nanoparticles - The Tiny Giants Shaping Modern Medicine
Nanoparticles, structures with dimensions in the nanometer range, have emerged as one of the most versatile platforms in modern medicine. When the mRNA COVID-19 vaccines reached billions of people in record time, it was lipid nanoparticles (LNPs) that made it possible1, protecting a fragile RNA payload to reach human cells and change the course of a pandemic. That same platform now underpins emerging gene therapies and a generation of cancer treatments moving through clinical trials. Polymeric nanoparticles are enabling targeted chemotherapy and sustained-release formulations2. Extracellular vesicles are being developed as natural and engineered delivery shuttles for gene therapy3. Gold nanoparticles are advancing rapid diagnostics and imaging4. Nanoparticles are not a future technology - they are the scaffolding modern medicine is being built on.
What that potential rarely acknowledges is its own prerequisite: a production workflow capable of delivering particles that are pure, stable, and intact.
The Workflow Everyone Tolerates
A standard nanoparticle production workflow moves through four stages: synthesis, harvesting, purification, and formulation. Synthesis gets all the attention. The other three stages get all the headaches.
After synthesis, a nanoparticle suspension contains far more than the target product. Residual solvents, unreacted lipids or polymers, free (non-encapsulated) drug, and biological debris all need to be removed. Post-purification, the particles need to be concentrated and formulated into a suitable buffer.
Nanoparticles are highly sensitive to their processing environment. Their size, surface chemistry, morphology, encapsulation efficiency, and colloidal stability can all be influenced by the forces and interfaces they encounter during purification, concentration, and buffer exchange. The processing method therefore matters, not only for recovery, but also for how effectively the final product retains its intended physical and functional properties.
In most research labs, that means a combination of ultracentrifugation, gel filtration (size exclusion chromatography, SEC), dialysis, and dead-end filtration (DEF), methods that were not designed for nanoparticles, and it shows.
The Real Cost of Conventional Methods
Ultracentrifugation separates nanoparticles by driving them into a concentrated pellet under very high centrifugal forces. The resulting high local particle concentration promotes particle-particle interactions and encourages aggregation. Resuspension of a compact pellet may require vigorous mixing, creating another source of mechanical stress and product loss. While effective for separating nanoparticles, the combination of high g-forces, pellet formation, and resuspension makes it less suitable when maintaining particle integrity and consistent recovery is critical.
Ultracentrifugation
Size Exclusion Chromatography
SEC offers a gentler alternative for impurity removal and buffer exchange. It separates nanoparticles based on their hydrodynamic size. As particles pass through the porous stationary phase, interactions with the matrix can cause adsorption and product loss. The process also typically dilutes the nanoparticle fraction, requiring an additional concentration step that introduces further handling. For sensitive nanoparticles, repeated particle-matrix interactions, dilution, and additional processing compromise recovery and stability. The method also requires elaborate optimization, and is limited by volume constraints.
SEC offers a gentler alternative for impurity removal and buffer exchange. It separates nanoparticles based on their hydrodynamic size. As particles pass through the porous stationary phase, interactions with the matrix can cause adsorption and product loss. The process also typically dilutes the nanoparticle fraction, requiring an additional concentration step that introduces further handling. For sensitive nanoparticles, repeated particle-matrix interactions, dilution, and additional processing compromise recovery and stability. The method also requires elaborate optimization, and is limited by volume constraints.
Size Exclusion Chromatography
Equilibrium dialysis relies on diffusion across a semipermeable membrane to remove small molecules and exchange buffers. Because the process is concentration-gradient driven, it is agonizingly slow. While mechanistically gentle, hours-long buffer exchange for a single sample is not a workflow, it is a waiting game.
Equilibrium Dialysis
DEF is fast to set up, accommodates small volumes, but its operating principle renders it unsuitable for nanoparticles. The sample is forced directly against the membrane, causing retained particles to accumulate at its surface. This creates concentration polarization and, as the process continues, a cake layer that blocks the membrane pores. Rising concentrations at the membrane also increase particle-particle and particle-membrane interactions, promoting fouling, aggregation, and recovery losses. The problem becomes more pronounced as nanoparticles are concentrated, making DEF poorly suited to high-recovery concentration workflows. The only way to track volume is by eye, between centrifuge spins, which means every run introduces operator-dependent variability.
Dead-End Filtration
Tangential Flow Filtration (TFF): A Different Principle Entirely
TFF solves the core problem by changing the geometry. Instead of driving the sample into the membrane, TFF flows it across the membrane surface. Small-molecule impurities pass through as permeate. The nanoparticles stay in circulation, swept along gently by tangential flow. This continuous crossflow helps minimize particle accumulation at the membrane surface, reducing the fouling and cake formation associated with DEF. And while impurities are being removed, the buffer is introduced into the closed retentate loop. Sample concentration and buffer exchange happen in an integrated approach, without requiring the nanoparticles to be repeatedly transferred between processing steps. This enables controlled processing while minimizing unnecessary handling and exposure to potentially damaging conditions.
Tangential Flow Filtration
TFF at the Lab Scale: The µPulse® and aµtoPulse®
For years, TFF existed only at manufacturing scale because the systems were too large and complex, and with hold-up volumes in hundreds of milliliters, far beyond the capacity of a research laboratory. Formulatrix changed that.
The µPulse® and aµtoPulse® are miniaturized TFF systems that are well-suited for lab-scale sample processing.
Start with as little as 500 µL and achieve a final volume down to 250 µL without compromising efficiency.
Recover the maximum of your sample with the miniaturized fluid path and the industry-wide lowest hold-up volume of just 250 µL.
Achieve up to 4x higher filtration rates compared to dead-end filtration units. A recent study has shown that the µPulse reduced melanin nanoparticle preparation from 2-3 days to just a few hours while improving particle homogeneity5. In a separate exosome study, µPulse processing produced particles with an average size of 110 nm compared with 150 nm using DEF, indicating reduced aggregation. In a protein formulation study, µPulse also achieved 98% recovery, equivalent to DEF, while completing the process 4 times faster.
Program your run and the system performs precise execution, eliminating operator-dependent variability.
Choose your throughput: Process a single sample with the µPulse and up to 54 samples per run with aµtoPulse (up to 4 samples in parallel).
One Workflow. Every Nanoparticle Type.
Whether LNPs, liposomes, exosomes, metal nanoparticles, or polymeric nanoparticles - the workflow is the same:
- Select the appropriate MWCO chip for your particle
- Load your crude suspension
- Set your target concentration and diafiltration parameters
- Walk away
No aggregation from centrifugal force. No hours-long dialysis. No concentration polarization from DEF. No guessing volumes.
Just your nanoparticles, intact, in the buffer they need to be in.
Conclusion
Nanoparticle science has moved fast but the processing workflows most labs rely on have not kept up. If aggregation, sample loss, and manual variability are the accepted cost of doing business, it is worth asking what an automated, single-step solution would change. The µPulse and aµtoPulse answer that question - at the bench, at the scale where nanoparticle research actually happens.
These systems are not limited to nanoparticles - they process proteins, nucleic acids, and viral vectors with equal efficiency, making them versatile tools across biopharmaceutical and life science workflows.
Want to Accelerate Your Nanomedicine Breakthroughs?
Explore how the µPulse and the aµtoPulse fit into your nanoparticle processing workflow.
Learn how the μPulse ensures a robust and efficient workflow for EV isolation and concentration in this application note.
References
1. Meerasa, S. S., Alshaer, W., & Goyal, K. (2025). Endosomal escape and current obstacles in ionizable lipid nanoparticles mediated gene delivery: Lessons from COVID-19 vaccines. International Journal of Pharmaceutics, 685, 126263.
https://doi.org/10.1016/j.ijpharm.2025.126263
2. Floyd, T. G., Gurnani, P., & Rho, J. Y. (2025). Characterisation of polymeric nanoparticles for drug delivery. Nanoscale, 17(13), 7738–7752.
https://doi.org/10.1039/D5NR00071H
3. Di Ianni, E., Obuchi, W., Breyne, K. & Breakefield, X.O. (2025). Extracellular vesicles for the delivery of gene therapy. Nature Reviews Bioengineering, 3(5), 360–373.
https://doi.org/10.1038/s44222-025-00277-7
4. Talik Sisin, N.N., Ab Rashid, R., Harun, A.Z., Geso, M., & Rahman, W.N. (2024). Comparative evaluation of gold nanoparticles as contrast agent in multimodality diagnostic imaging. Journal of Radiation Research and Applied Sciences, 17(4), 101079.
https://doi.org/10.1016/j.jrras.2024.101079
5. Vanhanen, P., Reinisalo, M., Lajunen, T., Kalinin, S., Leskinen, J., & Urtti, A. (2026). Effective process for screening melanin binding affinity of small molecule drugs and new drug candidates. International Journal of Pharmaceutics, 698, 126964.
https://doi.org/10.1016/j.ijpharm.2026.126964