How to Store Fragile Biological Materials Without Refrigeration
A method for preserving unstable biological materials like proteins by trapping them in a solid, glass-like sugar or polymer matrix that prevents decay at room temperature.
Original patent title: “USRE39497E1 - Storage of materials”
A method for preserving unstable biological materials like proteins by trapping them in a solid, glass-like sugar or polymer matrix that prevents decay at room temperature. Granted to Nektar Therapeutics in 2007 with 25 claims and 11 forward citations.
Key facts
Coverage
What does this patent actually cover?
This patent describes a way to keep delicate biological materials, such as proteins or enzymes, from breaking down when they are not kept in a fridge. It works by dissolving the fragile material into a water-soluble carrier, like a sugar or a synthetic polymer, and then turning that mixture into a solid, glassy, amorphous state. Because the material is locked inside this rigid 'glass,' it cannot move or react, effectively pausing its degradation at room temperature. When a scientist needs to use the material again, they simply add water to dissolve the glass and release the active substance.
The gap
What does this patent NOT cover?
- Does not cover materials that are already stable in aqueous solution at room temperature.
- Does not cover storage methods that rely on freezing or standard refrigeration.
- Does not cover the storage of rennin specifically, as it is explicitly excluded in claimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 17.
- Does not cover liquid-state storage solutions that do not form a glassy amorphous solid.
These exclusions are unique to PatentBrief — derived from the actual claim language, not patent-office boilerplate.
What made this novel
The innovation lies in using the glass transition state of a sugar or polymer matrix to physically immobilize molecules, preventing the molecular movement necessary for chemical degradation without needing to lower the temperature.
Schematic visualization of the patent's claim structure. Hand-drawn diagrams in progress for each landmark patent.
Where you've seen this
Real-world examples
Lyophilized (freeze-dried) protein therapeutics
Room-temperature stable diagnostic test reagents
Stabilized enzyme formulations for industrial use
Why it matters
The bigger picture
This technology is vital for the pharmaceutical and biotech industries, where shipping temperature-sensitive medicines like vaccines or therapeutic proteins is expensive and logistically difficult. By removing the need for a 'cold chain'—the continuous refrigeration of products from factory to patient—this method reduces costs and increases access to life-saving drugs in regions lacking reliable electricity.
Filed
August 28, 2001
Granted
February 27, 2007
Market context
Who's building on this
Companies in this space
Nektar Therapeutics continues to operate in the drug delivery space, focusing on polymer conjugate technology. Many pharmaceutical companies and contract manufacturing organizations utilize similar vitrification techniques to stabilize biologics for global distribution.
Market impact
This patent helped formalize the use of vitrification for pharmaceutical stabilization, moving the industry toward more robust, non-refrigerated drug delivery systems. It has been a foundational concept for companies aiming to eliminate the logistical burdens of the cold chain in global health initiatives.
Claim 1 — Plain English
What this patent covers
This patent describes a way to keep delicate biological materials, such as proteins or enzymes, from breaking down when they are not kept in a fridge. It works by dissolving the fragile material into a water-soluble carrier, like a sugar or a synthetic polymer, and then turning that mixture into a solid, glassy, amorphous state. Because the material is locked inside this rigid 'glass,' it cannot move or react, effectively pausing its degradation at room temperature. When a scientist needs to use the material again, they simply add water to dissolve the glass and release the active substance.
The clever bit
The innovation lies in using the glass transition state of a sugar or polymer matrix to physically immobilize molecules, preventing the molecular movement necessary for chemical degradation without needing to lower the temperature.
What it does not cover
- Does not cover materials that are already stable in aqueous solution at room temperature.
- Does not cover storage methods that rely on freezing or standard refrigeration.
- Does not cover the storage of rennin specifically, as it is explicitly excluded in claim 17.
- Does not cover liquid-state storage solutions that do not form a glassy amorphous solid.
Patent timeline
Application submitted to the patent office
Application published, typically 18 months after filing
Patent officially issued
PatentBrief Score
Impact Score
Moderate
Citation count
22/40
Moderately cited
Claim breadth
17/20
Very broad protection
Recency
5/20
Granted 10–20 years ago
Assignee scale
0/20
Independent or smaller assigneeassigneeThe entity that owns the patent — usually the inventor's employer or a company.Read more →
PatentBrief Impact Score — based on citation count, claim breadth, recency, and assignee scale. Not a legal assessment.
Heuristic Value Estimate
What this patent might be worth
$35K – $112K
Midpoint $70K · expired or expiring · industry ×3.0
Heuristic only — blends forward/backward citation counts, claim scope, time remaining, litigation history, and CPC-derived industry baseline. Real valuations need a professional appraisal.
The original legal language
Original claims
25 claims as filed with the patent office.
Concepts involved
Citations
Patent lineage
Cite this patent
Franks, F., & Hatley, R. H. M. (2007). How to Store Fragile Biological Materials Without Refrigeration (U.S. Patent No. RE39,497). U.S. Patent and Trademark Office. https://patentbrief.org/patent/us/RE39497/epogen-epoetin-alfa
Auto-generated from the patent record. Double-check author order and the issue date against the official USPTO document before submitting.
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Common Questions
Frequently Asked Questions
What does How to Store Fragile Biological Materials Without Refrigeration cover?
A method for preserving unstable biological materials like proteins by trapping them in a solid, glass-like sugar or polymer matrix that prevents decay at room temperature.
Who owns patent US RE39497?
Nektar Therapeutics owns this patent, granted in 2007.
When does this patent expire?
This patent is expected to expire on February 27, 2027, when the invention enters the public domain.
What is patent US RE39497 cited by?
This patent has been cited by 11 later patents that build on its ideas.
What problem does this patent solve?
This technology is vital for the pharmaceutical and biotech industries, where shipping temperature-sensitive medicines like vaccines or therapeutic proteins is expensive and logistically difficult. By removing the need for a 'cold chain'—the continuous refrigeration of products from factory to patient—this method reduces costs and increases access to life-saving drugs in regions lacking reliable electricity.
What does this patent NOT cover?
Does not cover materials that are already stable in aqueous solution at room temperature.
Patent monitoring