How does the biomolecular corona transform LNPs’ identity, and how can we engineer to enable next-generation genetic medicines?  

Why this matters. Every LNP injected into a living system gains a “biological identity” within seconds. Adsorbed proteins, lipids, and biomolecules form a biomolecular corona that determines the LNP’s circulation time, immune recognition, biodistribution, and ultimately its ability to deliver RNA where it is needed. Ignoring this layer risks failed targeting, faster clearance, and poor clinical translation.

Biomolecular corona → Clinical translation: Lessons from Onpattro®

The first-ever approved siRNA LNP therapeutic, Onpattro®, relies on the biomolecular corona, i.e., ApoE adsorption. Corona formation is not an accident, it is a functional step. In Onpattro, PEG-lipids with short C14 lipid chains are intentionally included to shield the LNP during manufacturing and storage. After intravenous injection, these PEG-lipids rapidly dissociate from the LNP in circulation, exposing the underlying lipid surface. This promotes binding of endogenous ApoE, which then mediates liver-specific uptake by interacting with LDL receptors on hepatocytes, a key mechanism for targeted delivery.

From synthetic to biological identity

The “synthetic identity” of LNPs (i.e., size, PDI, ζ-potential, composition) is only half the story. As soon as LNP systems get into contact with biological fluids such as blood a biological identity is built via the biomolecular corona. Soft corona proteins exchange rapidly; hard corona proteins bind strongly and persist. This corona modified LNP is what cells “see”.

3 bullet point primer on the biomolecular corona architecture

• Soft corona (seconds–minutes): Weak, dynamic layer reflecting the momentary milieu.

• Hard corona (minutes–hours): Stable layer that defines receptor engagement, opsonization, and cell uptake.

• Non-protein actors: Lipoproteins (HDL/LDL/IDL), lipids, and nucleic acids can co-assemble and change trafficking.

Figure 1 - Visual Representation of the Protein Corona Forming on a Nanoparticle Surface

Shaping the biomolecular corona to impact delivery

The liver has long been the default destination for LNPs, largely due to protein corona interactions that favor hepatocyte-specific delivery. By intentionally modulating the corona (through lipid composition, morphology, or surface chemistry) developers can shift organ tropism beyond the liver, i.e., optimizing lipid composition to tune which proteins are (or are not) recruited and which organs are reached.

• ApoE-rich coronas → Liver targeting via LDL receptors on hepatocytes; PEG-lipid detachment after injection promotes ApoE adsorption, a key mechanism used by Onpattro.
• Vitronectin-rich coronas → Tumor targeting via αvβ3 integrin interactions, often found on angiogenic tumor vasculature.
• Reduced corona formation → Recent studies show that the structure of an LNP can affect the protein corona. LNPs with lipid bilayers exhibit reduced protein adsorption in plasma compared to traditional solid-core LNPs. This reduction in non-specific corona formation can contribute to prolonged systemic circulation and enhanced delivery to extrahepatic tissues like lymph nodes or spleen. These insights emphasize the importance of rationally designed morphology in shaping corona dynamics, not just composition.

Moving Beyond ApoE: The HDL Connection

Understanding the relationship between LNP composition, corona makeup, and delivery efficacy remains a frontier challenge. A recent study took a multiomics-driven approach to tackle this complexity, revealing that efficacy isn’t just determined by which proteins bind but also by how we study them.

• LNPs were incubated with plasma from individual lean or obese rats, retrieved with intact coronas, and functionally evaluated in vitro.

• The most efficacious corona profiles were enriched with high-density lipoprotein (HDL), which turned out to be a better predictor of in-vivo potency than ApoE alone.

• HDL was revealed as not just a component but a source of ApoE, reshaping the understanding of how ApoE contributes to liver tropism.

• These insights underscore the role of physiology (obesity, metabolic state) in shaping corona composition and therapeutic outcomes.

This study underscores the value of high-throughput corona profiling tools that preserve corona integrity while enabling omics-scale analysis.

Innate & adaptive immunity: Where the biomolecular corona meets the immune system

Once an LNP enters the bloodstream, it immediately encounters the immune system’s front line. The adsorbed biomolecular corona determines how the body perceives the LNP - as a harmless passenger or a potential intruder. Corona proteins can activate components of the innate immune system, such as complement factors and macrophages, while shaping downstream adaptive immune responses through antigen presentation or antibody generation. Understanding this crosstalk between the corona and immune surveillance is key to balancing efficacy, tolerability, and re-dosing potential in next-generation RNA therapeutics.

Innate immunity (first minutes–hours)

• Complement activation & opsonization: Corona recruitment of C3/C4 and immunoglobulins tags LNPs for uptake by Kupffer cells (liver resident macrophages), splenic macrophages, and monocytes. Excess activation can trigger CARPA (complement activation–related pseudoallergy) with C3a/C5a release.

• Pattern-recognition receptors (PRRs): TLRs (e.g., TLR7/8 for ssRNA), scavenger receptors, and complement receptors sense corona-decorated particles, driving cytokines (IL-6, TNF-α) and rapid clearance.

• Label exchange pitfalls: Detachable PEG-lipids or lipid-like fluorophores/radiolabels exchange with endogenous lipoproteins and confound PK/BD readouts. It is key to validate probes and use organ-homogenate quantification, not only whole-body imaging.

• Adaptive immunity (days–weeks; relevance for re-dosing)

• ABC phenomenon (Accelerated Blood Clearance): Anti-PEG IgM/IgG, pre-existing or induced, accelerate clearance upon repeat dosing of PEGylated systems.

• Memory responses: Re-exposure can amplify anti-PEG/anti-ligand antibodies, shortening half-life and increasing hypersensitivity risk.

• Mitigations: Cleavable/biodegradable PEG, alternative stealth coatings, tuned dosing intervals, steroid/antihistamine pre-meds, and complement inhibitors.

Potential immuno-assessments

• Complement panels: CH50/AH50, C3a/C5a, sC5b-9.

• Cytokine release (human PBMCs): IL-6, TNF-α, IFN-α/β; TLR reporter assays for RNA sensing.

• Phagocytosis/uptake: Human macrophage/Kupffer cell models ± serum.

• Anti-PEG / anti-drug antibodies (ADA) baseline & on-study: ELISA/bridging assays; correlate to PK shifts (ABC).

• Repeat-dose PK/BD in vivo: Look for half-life collapse and liver/spleen shunting.

We learned from PEGylated liposomes that ABC and CARPA can emerge on re-dose; surface ligands or new chemistries should be screened for these liabilities early in LNP development.

Cutting through the complexity

As LNPs advance into more complex therapeutic settings, understanding and controlling corona formation becomes more and more important. By integrating morphology, composition, and corona analytics early in development, formulation teams can rationally guide performance outcomes.

Think of corona engineering as part of Quality by Design (QbD): define your Quality Target Product Profile (QTPP), map your Critical Process Parameters (CPPs such as PEG-lipid %, ionizable lipid pKa, helper lipid ratios), measure resulting corona fingerprints, and correlate them to circulation time, biodistribution, potency and immunogenicity. Only then lock specs for late-stage development. Table 1 provides a concise guide for implementing corona characterization within LNP development workflows.

Table 1: Practical Playbook for studying the LNP corona

Non-negotiables to lock early in development

To design LNPs with predictable behavior, teams should:

• Mimic the right biological environment in vitro – Test in human plasma or full blood at 37°C, not just 10 % FBS.
• Profile corona composition – Identify key proteins (ApoE, complement factors, albumin, clusterin) that dominate the surface.
• Assess stability under shear stress – Look for aggregation, lipid shedding, and premature RNA release.
• Link PEGylation kinetics to targeting – Match PEG density/chain length/lipid anchor with desired circulation vs. de-PEGylation rates.
• Immune risk screen (repeat-dose minded): Complement activation, cytokine release, anti-PEG antibodies, and ABC/CARPA (details below).

Decision rules for corona engineering

Promote a corona study from exploration to development-critical when:

• You see strong correlation between corona composition and potency.
• Variability in corona proteins explains differences in efficacy.
• PEGylation/detachment kinetics are known and reproducible under physiological conditions.

Keep corona profiling exploratory when:

• Assay reproducibility is low (e.g., cross-lab variability).
• Separation techniques cannot exclude lipoprotein contamination.
• No clear CPP→corona→efficacy linkage has been shown yet.

Ask Your Team/CDMO

• Which biofluids and conditions are used for corona studies, i.e., species, temperature, shear stress?
• How are soft vs. hard corona proteins distinguished?
• Are we separating LNPs from lipoproteins and EVs (IDL, HDL, exosomes)?
• Which recovery method is used (SEC, gradient centrifugation, magnetic separation, cross-linking), and what bias does it introduce?

Final Takeaway

The biomolecular corona is not just a nuisance, it is a key parameter - one that can be modulated to improve biodistribution, avoid immune clearance, and guide LNPs toward desired cell types. As the field matures, we may move from corona avoidance to corona engineering - intentionally recruiting proteins to create targeting motifs, guide immune interactions, or extend circulation half-life.

Take a look at the comparative table of corona-isolation techniques and revisit our foundational article on critical quality attributes (CQA) mapping to see how corona characterization fits into the CPP→CQA→QTPP framework for next-generation genetic medicines.

Download the file here.

Written by

Dr. Dominik Witzigmann 

Dominik is an entrepreneurial scientist with deep expertise in nanomedicines and nucleic acid delivery. In 2024, he was named Highly Cited Researcher, recognizing him among the world’s most influential researchers in the field. Dominik obtained his Ph.D. in Pharmaceutical Technology from the University of Basel in Switzerland, and held research positions at leading institutions including University College London (safety/tox), German Cancer Research Center (RNAi & cancer), University of Basel (targeted nanomedicines & DNA delivery) and the University of Zurich (mRNA-based genome editing). To focus on extrahepatic RNA delivery, he later joined the team of Prof. Pieter Cullis at the University of British Columbia. Dominik has held leadership roles in Canada’s NanoMedicines Innovation Network (NMIN) and served on the Board of the CRS Gene Delivery and Genome Editing Focus Group. To translate next-generation LNP technologies into the clinic, Dominik co-founded and leads the LNP-nucleic acid company NanoVation Therapeutics. 

Dr. Jayesh Kulkarni

Dr. Kulkarni obtained his PhD from the University of British Columbia and has over 15 years experience in the nanoparticle drug delivery field. He has published over 40 peer-reviewed articles and is a co-inventor on numerous patents. Dr. Kulkarni’s research has focused on the role of the various lipid components in LNP and the biophysics that governs particle formation. His work has contributed to clinical translation, including scale-up and manufacturing of LNP systems in accordance with GLP and GMP regulations. Dr. Kulkarni is a leader in the design and development of lipid nanoparticle (LNP) formulations of small molecule and nucleic acid therapeutics. He currently serves as the Chief Scientific Officer of NanoVation Therapeutics, an LNP-RNA formulation developer.

Dr. Mireya L. Borrajo

Mireya L. Borrajo is an advisor at Eli Lilly (Boston, USA). Before that, she did her postdoc at Eli Lilly and obtained her PhD in Drug Research and Development at University of Santiago de Compostela (Spain), under the supervision of Prof. María José Alonso, researching polymeric and lipid-based formulations for RNA delivery for therapeutic applications. She obtained her B.Sc. in Biochemistry and her M.Sc. in Advanced Nanoscience and Nanotechnology at Autonomous University of Barcelona (Spain). She is the Industry Representative of the Gene Delivery and Gene Editing Focus Group of the CRS.

Dr. Marija Petrovic 

Marija is a pharmacist with a PhD in Biopharmacy from the University of Geneva, and a cancer research (ISREC)–trained professional through EPFL, with over seven years of experience in nanomedicine. During her PhD, she worked on miRNA and STING ligand nanocomplexes for cancer immunotherapy, gaining deep expertise in nanoparticle characterization and translational workflows. Certified by the EU-NCL in nanobiotechnology and awarded by Innosuisse (Swiss Innovation Agency) with two prizes (jury and public) for the best life science project, she also earned support from FONGIT, Geneva’s leading deep-tech incubator. As the founder of NanoSphere and an active contributor to the Controlled Release Society (Communication Chair for the Gene Delivery and Editing Group (GDGE), and Industry representative at Nanomedicine and Nanoscale Delivery (NND)), Marija focuses on making next-gen medicine scientific advances more visible, understandable, and useful to the communities that can turn them into impact.