Biodistribution
Visualizing where your oligo goes—and making sense of what it means
Biodistribution
—and making sense of what it means
Getting There is Half the Battle
In the development of siRNA and antisense oligonucleotide (ASO) therapeutics, ensuring delivery to the correct tissue or cell type is essential. A well-designed oligo must not only knock down its target effectively but also reach the target site in a biological system. Without accurate biodistribution, even the most potent molecule may fail in vivo.
Oligonucleotide biodistribution is influenced by many factors, including:
- Sequence length and structure
- Charge and hydrophobicity
- Conjugates and delivery vehicles
- Backbone and sugar modifications
- Route of administration (IV, SC, IP, etc.)
Understanding how these elements affect tissue exposure and cellular uptake is key to making informed decisions during preclinical development.
Why Biodistribution Data Matters
Biodistribution studies help answer critical questions and support essential development activities.
- Does the oligo reach the intended organ or tissue?
- Is it accumulating in non-target tissues with potential toxicities?
- How does a new conjugate or modification affect delivery?
- Is the route of administration optimal for therapeutic exposure?
- Are observed biological effects consistent with localization patterns?
These data are essential for:
- Lead candidate selection
- Delivery strategy refinement
- Regulatory filings
- Safety and PK/PD modeling
- Translational studies into clinical settings
Why Detecting Modified Oligos Is So Difficult
The very modifications that allow oligonucleotides to resist degradation and persist in circulation also make them harder to detect. Most existing detection methods were not designed for fully stabilized, short synthetic RNAs, and they come with serious tradeoffs.
PNA-based Assays
Mass Spectrometry
Offers sequence-specific hybridization
Delivers high specificity and quantitative precision
Suffers from low sensitivity, high input requirements, and tedious protocols
Requires expensive instrumentation, expert personnel, and custom tissue workflows
Not practical for routine use or broad screening
ELISA-based Detection
PCR-based Methods
Time-tested approach
Theoretically sensitive (e.g., stem-loop PCR)
Limited by sequence dependence and modification interference
Limited compatibility with modified backbones
Difficult to scale or adapt to new oligo designs
In short, traditional tools for biodistribution analysis struggle with specificity, quantification, and scalability-leaving researchers with partial or unreliable data
Why Detecting Modified Oligos Is So Difficult
The very modifications that allow oligonucleotides to resist degradation and persist in circulation also make them harder to detect. Most existing detection methods were not designed for fully stabilized, short synthetic RNAs, and they come with serious tradeoffs.
PNA-based Assays
Offers sequence-specific hybridization
Suffers from low sensitivity, high input requirements, and tedious protocols
Mass Spectrometry
Delivers high specificity and quantitative precision
Requires expensive instrumentation, expert personnel, and custom tissue workflows
Not practical for routine use or broad screening
ELISA-based Detection
Time-tested approach
Limited by sequence dependence and modification interference
Difficult to scale or adapt to new oligo designs
PCR-based Methods
Theoretically sensitive (e.g., stem-loop PCR)
Limited compatibility with modified backbones
In short, traditional tools for biodistribution analysis struggle with specificity, quantification, and scalability-leaving researchers with partial or unreliable data
HYBRID-ON™: Sequence-Specific, Quantitative, and Tissue-Resolved
To bridge this gap, ADViRNA developed HYBRID-ON™: a next-generation assay platform designed specifically to quantify fully modified oligonucleotides in tissue sections.
- Sequence-specific (distinguishes between closely related oligos)
- Quantitative (generates relative abundance data)
- Compatible with fully modified siRNAs and ASOs
- Scalable and reproducible for comparative biodistribution studies
Applications include:
Compare Delivery Strategies
Evaluate how different conjugates (e.g., GalNAc vs. cholesterol) and chemical modifications influence biodistribution
Confirm Target Delivery
Confirm delivery to tissues/cell types of interest (e.g., hepatocytes, neurons, muscle)
Support Critical Decisions
Generate data to guide preclinical safety, efficacy, and candidate selection
Delivery Data That Drives Strategy
Whether you’re testing a new modification, validating a delivery ligand, or refining your route of administration, reliable biodistribution data can unlock critical insights – and prevent costly dead ends.
Is Your Oligo Getting Where It Needs To Go?
Contact us to discuss how our biodistribution capabilities can support your next oligonucleotide program.
Is Your Oligo Getting Where It Needs To Go?
Contact us to discuss how our biodistribution capabilities can support your next oligonucleotide program.