Precision SHM-enabled microfluidic production of lipid nanoparticles for reproducible RNA, gene, and small-molecule delivery programs.
Staggered herringbone micromixer (SHM) technology has become a preferred microfluidic strategy for LNP preparation when formulation teams need rapid mixing, narrow size distribution, and robust batch-to-batch control. In SHM channels, chaotic advection accelerates ethanol-aqueous mixing, shortens local concentration gradients, and creates a more uniform environment for nanoparticle self-assembly. For developers working on mRNA, siRNA, pDNA, peptide, protein, or hydrophobic payload programs, this translates into tighter control over particle size, PDI, encapsulation behavior, and process reproducibility.
BOC Sciences provides SHM LNP production services for research and pre-manufacturing development. We design and optimize SHM-driven LNP workflows around your target CQAs, including size window, dispersity, loading behavior, colloidal stability, and application-specific performance. Whether you are comparing SHM against hydrodynamic flow focusing, transferring a benchtop formulation into a more reproducible microfluidic process, or refining an RNA delivery candidate for downstream studies, our team builds a practical route from screening to scalable production logic.
Staggered Herringbone Device for mRNA LNPsOur service package is built for scientists who need more than simple particle preparation. We help define the right mixer strategy, optimize formulation-process interactions, and generate LNPs with properties aligned to your development objectives.
We assess whether SHM microfluidics is the right production route for your payload, lipid composition, throughput target, and critical particle attributes.
We run structured screening studies to identify lipid combinations and operating windows that support efficient self-assembly under SHM mixing conditions.
SHM performance depends on how formulation chemistry and mixing dynamics interact. We optimize the process variables that most strongly affect nanoparticle formation.
We prepare SHM-derived LNPs for multiple molecule classes, with production logic tailored to the physicochemical sensitivity of each payload.
We help teams move from exploratory runs toward more robust and transferable SHM production settings without losing formulation identity.
Production data are only useful when connected to particle behavior. We characterize the resulting LNPs and relate the findings back to mixer and formulation settings.
Successful SHM production requires simultaneous control of mixer geometry, formulation chemistry, and microfluidic operating conditions. Our development strategy focuses on the variables that most directly influence self-assembly quality and reproducibility.
From formulation screening to process-window definition, we help translate SHM mixing into practical LNP production outcomes.
Our SHM LNP production service is designed for payload-specific development needs. We do not force all programs into one fixed workflow; instead, we adjust formulation and process logic to the molecule class, desired particle profile, and downstream research goal.
| Payload / Program Type | Typical SHM Production Focus |
|---|---|
| mRNA LNP Programs | Control of particle size, narrow PDI, and high encapsulation under conditions suitable for translation-focused formulation development. |
| siRNA LNP Programs | Optimization of compact particles with efficient siRNA loading, stable colloidal behavior, and reproducible SHM mixing performance. |
| Gene Delivery LNP Systems | Development of LNPs for plasmid, RNA, or related nucleic acid payloads where process consistency and payload protection are critical. |
| Peptide-Loaded LNPs | Screening of process conditions that reduce surface-associated loss and improve loading distribution for amphiphilic or sensitive peptides. |
| Protein-Loaded LNPs | Adjustment of aqueous phase conditions and mixing intensity to preserve protein functionality while forming stable lipid carriers. |
| Small-Molecule and Combination Payloads | SHM process adaptation for hydrophobic or co-loaded systems where solvent exchange rate and lipid composition strongly influence particle structure. |
✔ Broad Particle Size Distribution
When self-assembly occurs under poorly controlled mixing, particle populations widen quickly. We use SHM-driven rapid mixing plus formulation optimization to compress size distribution and lower PDI.
✔ Unstable Encapsulation Performance
Variability in solvent exchange often leads to inconsistent payload loading. We identify the TFR, FRR, and concentration combinations that support more stable encapsulation behavior across repeated runs.
✔ Difficult Transition from Manual Mixing
Bulk or hand-mixed formulations may show promising early signals but poor reproducibility. Our SHM workflows provide a more controlled route for translating those concepts into repeatable LNP production.
✔ Payload-Specific Process Fragility
Different payloads respond differently to pH, concentration, and solvent exposure. We adapt the production route to RNA, proteins, peptides, or small molecules rather than treating all cargos the same way.
✔ Poor Run-to-Run Consistency
Development programs often stall because a formulation works once but not reliably. We define process windows and replicate conditions to improve run reproducibility before broader scale bridging.
✔ Unclear Mixer Selection Strategy
Teams frequently need to understand whether SHM, T-junction, or alternative microfluidic approaches are better suited to their formulation. We make that choice evidence-based rather than trial-and-error.
We review your payload type, target size range, desired dispersity, formulation constraints, and intended development use to create an SHM production plan.
Initial design-of-experiment style studies evaluate lipid composition, FRR, TFR, and concentration ranges to identify promising self-assembly conditions.
Selected conditions are refined through replicate SHM runs and physicochemical characterization, including size, PDI, zeta potential, and encapsulation analysis.
We deliver a structured summary of the best-performing conditions, major process sensitivities, and the recommended next-step route for your LNP program.
Challenge: A client developing a liver-directed mRNA formulation needed particles below 90 nm with a PDI below 0.15, but their existing preparation route generated batches between 75 and 140 nm with unstable dispersity.
Project Characteristics: The formulation used a four-component lipid system with an ionizable lipid, cholesterol, phospholipid, PEG-lipid, and capped mRNA in acidic aqueous buffer. The team needed a more reproducible process before expanding formulation screening.
Our Exploration Strategy: We established an SHM screening matrix covering multiple FRR settings, two feed concentration windows, and several TFR levels. Early runs showed that the client's original lipid concentration was too high for the intended size target under rapid mixing. We then shifted to a lower concentration window, narrowed the FRR range, and introduced a controlled post-mixing buffer transition to reduce fusion events.
Result: The optimized SHM condition delivered particles centered at approximately 78-85 nm with PDI consistently below 0.12 across repeated runs, while preserving strong encapsulation performance. The client obtained a narrower, more transferable operating window for subsequent expression-focused studies.
Challenge: A siRNA program required compact, homogeneous LNPs with high encapsulation and low run-to-run variation, but initial SHM production gave acceptable size in one run and poor loading consistency in the next.
Project Characteristics: The payload was a duplex siRNA intended for in vitro knockdown evaluation. The client suspected that the issue was not only composition but also a mismatch between FRR, N/P ratio, and aqueous phase composition.
Our Exploration Strategy: We compared several N/P settings under a constant base composition, then overlaid FRR and TFR adjustments to isolate where loading variability emerged. Additional work showed that the broadest variability occurred when the aqueous feed concentration and FRR combination created an unstable self-assembly zone immediately downstream of the mixer. We refined the operating window and selected conditions that balanced compact particle formation with more reliable siRNA incorporation.
Result: The final SHM process produced siRNA LNPs with size near 60-70 nm, PDI under 0.15, and encapsulation values repeatedly above 90%. More importantly, the client gained a defined process window that reduced batch drift during follow-up formulation work.
Process-First Development ThinkingWe do not treat microfluidic chips as black boxes. We connect mixer design, flow conditions, and formulation chemistry to the particle attributes you actually need.
Deep LNP Application CoverageOur teams support broad lipid nanoparticles for drug delivery needs across RNA, peptide, protein, and combination payload programs.
Relevant Technical ContextWe build projects with awareness of the broader design logic described in resources such as LNP delivery systems and formulation mechanism fundamentals.
Optimization Beyond Particle Size AloneWe consider size, PDI, loading behavior, colloidal stability, and process repeatability together, helping avoid false optimization around a single number.
Conversion-Oriented Technical CommunicationOur service outputs are designed to help project teams make clear next-step decisions, including formulation ranking, parameter selection, and broader process direction.
The Staggered Herringbone Micromixer (SHM) is a microfluidic mixing element based on chaotic advection principles. Its structural characteristic involves arranging a series of inclined micro-"herringbone" protrusions on the channel bottom; when two-phase fluids (organic phase and aqueous phase) pass through the channel, these protrusions generate secondary vortices perpendicular to the main flow direction, achieving uniform mixing in far less time than molecular diffusion would require. SHM chip structural parameters (such as channel height, herringbone angle, and arrangement density) determine mixing efficiency. BOC Sciences is equipped with multiple specifications of SHM chip platforms, enabling optimization of mixing elements based on client formulation characteristics and production requirements, providing reliable microfluidic technical support for LNP production.
SHM mixing efficiency is influenced by both chip geometric parameters and operating conditions. Geometric parameters include channel aspect ratio (height to width), herringbone inclination angle (typically 45 to 60 degrees), herringbone unit length and spacing, and total channel length. These structural parameters determine the intensity and coverage of secondary vortices. Regarding operating conditions, total flow rate affects Reynolds number and vortex formation efficiency; typically there exists an optimal flow rate window maximizing chaotic mixing. Flow rate ratio (FRR) affects local supersaturation and nucleation kinetics. BOC Sciences establishes parameter-performance relationship models through systematic parameter characterization studies, providing clients with precise process optimization recommendations.
The advantages of SHM technology in LNP production are primarily reflected in several aspects: relatively simple structural design facilitating manufacturing and cost control; high mixing efficiency achieving rapid uniform mixing within a compact chip footprint; fine control over mixing intensity through adjusting herringbone arrangement density in channels; and good universality across diverse lipid formulations. Additionally, SHM chips can integrate with other functional units (such as inline mixing and inline dilution) to achieve continuous production. BOC Sciences SHM platform has been validated through numerous projects, demonstrating stable and reliable process performance in LNP production for various nucleic acid types including mRNA and siRNA.
SHM, Hydrodynamic Flow Focusing (HFF), and Dean flow technology constitute the mainstream technology routes for microfluidic LNP production. SHM relies on chaotic mixing for efficient mixing, suitable for applications with high mixing speed requirements; HFF relies on laminar flow focusing for precise control, suitable for fine parameter exploration during early development; Dean flow relies on secondary flow effects in curved channels, suitable for scale-up and higher viscosity formulations. Selection requires comprehensive consideration of target particle size range, formulation viscosity characteristics, throughput requirements, and budget factors. For feasibility assessment during formulation development, SHM and HFF are more flexible choices; for scaled manufacturing, Dean flow technology offers greater linear scale-up advantages. BOC Sciences technical team provides professional technical evaluation and selection recommendations.
SHM chip clogging is a common challenge during process operation, with primary mitigation strategies including: raw material pretreatment, filtering lipid solutions and buffers through 0.22 μm membrane filters to remove particulate impurities; formulation optimization, improving lipid solubility in organic phase to avoid precipitation from high concentrations; operating parameter adjustment, appropriately increasing total flow rate to enhance flushing force while balancing mixing efficiency; and chip selection, choosing chip models with larger channel dimensions for high-concentration or high-viscosity formulations. BOC Sciences has established comprehensive SHM process problem diagnosis procedures, enabling rapid clogging cause identification and providing targeted solutions for clients, ensuring smooth process operation.
