Accelerated Aging of Bioresorbable Polymer Scaffolds
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for accelerated aging of bioresorbable polymeric medical devices, such as stents, are inefficient and do not accurately predict long-term functional outputs like radial strength, expandability, and recoil, leading to delays in product development and regulatory approval.
Innovation Solution
A method involving exposing bioresorbable polymeric scaffolds to water at controlled temperatures for selected aging times, which mimics real-time aging processes, allowing for the measurement of functional outputs like radial strength, expandability, and recoil, using an accelerated aging factor of 100 to 1000 to simulate extended storage conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If accelerated aging methods are used to determine shelf life, then the time required for testing is reduced, but the accuracy of predicting long-term functional outputs deteriorates
Solution Approach 1:
The patent applies parameter changes by modifying temperature and humidity conditions during accelerated aging tests. Specifically, it tests at elevated temperatures (e.g., 40°C, 50°C, 60°C) and controlled humidity levels to accelerate the aging process while maintaining predictive accuracy for long-term functional outputs like radial strength, expandability, and recoil.
Solution Approach 2:
The patent replaces time-based prediction with environment-based acceleration. Instead of waiting for natural aging over years, it substitutes controlled environmental conditions (temperature-humidity-time combinations) to accelerate degradation mechanisms, allowing functional outputs to be measured much faster while preserving prediction accuracy.
2Productivity
If conventional accelerated aging conditions are applied, then testing speed increases, but functional outputs such as radial strength and expandability cannot be accurately predicted
Solution Approach 1:
The patent incorporates feedback by continuously monitoring and comparing functional outputs (radial strength, expandability, recoil) at different aging stages. It uses this feedback to validate whether the accelerated aging conditions accurately reflect real-time aging behavior, adjusting test parameters as needed to maintain prediction reliability.
Solution Approach 2:
The patent performs preliminary characterization of the polymer material's aging behavior under controlled conditions before conducting full scaffold testing. This preliminary action establishes degradation kinetics and functional output relationships that guide subsequent accelerated aging tests, ensuring reliable predictions.
3Measurement precision
If real-time aging testing is performed to ensure accurate predictions, then prediction accuracy improves, but product development timeline extends
Solution Approach 1:
The patent employs periodic testing at multiple time points during accelerated aging (e.g., early, mid, and late stages) to capture the aging trajectory. By periodically measuring functional outputs and fitting degradation models to this time-series data, it can accurately predict long-term performance without requiring actual real-time aging for the entire duration.
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
This method effectively predicts the long-term performance of bioresorbable scaffolds by accelerating the aging process, ensuring functional outputs remain within specifications, thereby speeding up product development and regulatory approval processes.
Implementation Method 1
exposing the scaffold to water at a controlled temperature for a selected aging time less than a desired shelf life of the scaffold
Implementation Method 2
exposing the scaffold to water at a controlled temperature for a selected aging time
Data Source
AI summary
A method of accelerated aging of bioresorbable polymer scaffolds including exposing the scaffold to water is disclosed. The scaffold is exposed to water at a controlled temperature for a selected aging time. The functional outputs, such as radial strength, expandability, and % recoil obtained from aged scaffolds predict those of real-time aging of the scaffold. The accelerated aging factor, which is the required shelf life divided by the aging time, is significantly higher for poly(L-lactide) scaffolds tested than thermal aging.