Dry Powder Hydrogel Formulation for Aortic Aneurysm Repair
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Solution Overview
Problem
Existing treatments for aortic aneurysms require thermally activated free radical initiators to be kept frozen, limiting their shelf life and making them unsuitable for immediate use, as rapid thawing methods are not feasible due to thermal activation and instability at ambient temperatures.
Innovation Solution
A dry powder formulation containing a prepolymer and a thermally activated free radical initiator, such as sodium persulfate, which can be stored at ambient conditions and rapidly reconstituted with a buffered aqueous solution to form a hydrogel, eliminating the need for freezer storage and allowing for terminal sterilization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If thermally activated free radical initiators are stored in aqueous solution, then the polymerization reaction can proceed at physiological temperature, but the solution must be kept frozen and has limited shelf life of 12 to 18 months
Solution Approach 1:
The patent changes the physical state of the initiator from aqueous solution to dry powder form, which fundamentally alters the storage requirements. The dry powder initiator can be stored at ambient temperatures without freezing, extending shelf life while maintaining the ability to initiate polymerization at physiological temperatures when reconstituted and activated.
Solution Approach 2:
The patent separates the storage and activation functions into distinct phases: the dry powder initiator is stored separately in a stable form, then reconstituted and activated at the site of use. This segmentation allows long-term stable storage while enabling temperature-dependent polymerization when needed.
2Loss of time
If rapid thawing methods are used to prepare frozen initiator solutions, then immediate use is possible, but thermal activation of the initiator occurs causing instability at ambient temperatures
Solution Approach 1:
Instead of thawing a frozen solution to achieve immediate use, the patent inverts the approach by using a dry powder formulation that requires no thawing process. The dry powder is reconstituted with solvent and then activated, eliminating the thermal shock and instability problems associated with rapid thawing while enabling immediate use.
3Reliability
If the free radical initiator solution is kept frozen at zero degrees Celsius or lower, then polymerization is prevented until needed, but the solution becomes unstable at ambient temperatures
Solution Approach 1:
The patent changes the storage parameter from temperature-dependent (frozen aqueous solution) to form-dependent (dry powder). This parameter change allows the initiator to remain stable at ambient temperatures during storage, while still enabling controlled polymerization when reconstituted and activated at physiological temperatures.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The dry powder formulation provides a stable composition with a long shelf life, rapid dissolution, and reduced prep time for surgery, while maintaining the desirable mechanical properties of hydrogels formed by existing processes.
Implementation Method 1
The polymerization is effected by combining both prepolymers with a thermally activated low temperature free radical initiator and an initiator catalyst at physiological temperature
Implementation Method 2
rapid dissolution
Data Source
AI summary
The present invention provides a dry powder that is suitable for use in forming a hydrogel and characterized by a stable composition at ambient conditions. The dry powder includes a prepolymer including a straight chain polyethylene glycol, and a thermally activated free radical initiator selected from the group consisting of sodium persulfate, potassium persulfate, and ammonium persulfate. The present invention also provides a method of forming the dry powder, and a method of preparing a hydrogel where a reaction mixture is formed including the dry powder and a buffered aqueous solution.