Bioresorbable Thiol-Yne Elastomers for Independent Mechanics and Degradation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing synthetic degradable elastomers lack independent control over mechanical properties and degradation rates, leading to issues such as heterogeneous degradation, rapid degradation, and inflammatory responses, making them unsuitable for long-term implantable applications in regenerative medicine.
Innovation Solution
A series of biodegradable elastomers are developed using nucleophilic thiol-yne polymerization, incorporating degradable C4 - C14 dicarboxylic acid-based monomers like succinic, glutaric, or adipic acid units, allowing independent tuning of mechanical properties and degradation rates through stereochemistry, with at least 50% of double bonds in a cis configuration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If crosslinking or blending is used to achieve desirable mechanical and degradation properties in degradable thermoplastic elastomers, then mechanical properties are improved, but degradation becomes heterogeneous and mechanical properties decrease exponentially
Solution Approach 1:
The patent changes the chemical composition parameters by incorporating specific degradable units (orthoesters, anhydrides, carboxylic acids) into the polymer backbone, replacing crosslinked structures. This allows homogeneous degradation while maintaining mechanical properties through compositional control rather than structural crosslinking.
2Duration of action of stationary object
If polyurethanes are modified to include varied amounts of hydrolytically degradable esters and other degradable units, then degradation control is improved, but degradation becomes heterogeneous due to anisotropic degradation within soft blocks
Solution Approach 1:
The patent creates homogeneous degradation throughout the material by distributing degradable units uniformly in the polymer backbone rather than concentrating them in soft blocks. This eliminates anisotropic degradation and ensures uniform degradation kinetics throughout the entire material structure.
3Strength
If chemically crosslinked polymers like PGS are used to achieve elastic properties mimicking soft tissues, then mechanical properties are improved, but degradation occurs too rapidly (around 6 weeks in vivo)
Solution Approach 1:
The patent modifies the degradation time parameter by selecting specific degradable units with controlled hydrolysis rates (orthoesters, anhydrides, carboxylic acids) and adjusting their composition ratios. This allows tuning of degradation time from weeks to months while maintaining elastic properties through compositional design rather than crosslinking.
4Reliability
If degradable units are incorporated into elastomer structures to facilitate resorption, then biodegradation is improved, but mechanical properties and degradation rates cannot be controlled independently
Solution Approach 1:
The patent segments the control of mechanical properties and degradation rates into independent parameters: mechanical properties are controlled by the base polymer structure and crosslink density, while degradation rates are controlled by the type and amount of degradable units incorporated. This segmentation allows independent optimization of both properties.
5Reliability
If poly(L-lactic acid) and poly(ε-caprolactone) are used for regenerative medicine applications, then initial promise is shown, but commercial scaling is difficult and thermal and mechanical properties are limited by rigid synthetic systems
Solution Approach 1:
The patent enables broad tunability of thermal and mechanical properties by varying the composition ratios of different degradable units (orthoesters, anhydrides, carboxylic acids) and adjusting crosslink density. This provides continuous adjustment of properties to match specific tissue requirements, overcoming the fixed properties of conventional polymers.
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
These elastomers exhibit controlled biodegradation, minimal inflammation, and excellent in vitro cell viability, providing a flexible material for soft tissue engineering and other medical applications with tunable mechanical properties.
Implementation Method 1
A metal-free, stereocontrolled step-growth polymerization via a nucleophilic thiol-yne addition which yielded a series of thermally-processable elastomers
Implementation Method 2
the incorporation of cis-1,4 alkene segments, to control the mechanical properties
Implementation Method 3
degradable units that facilitate resorption
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
In various embodiments, the present invention relates to a series of biodegradable thiol - yne elastomers that incorporate degradable C4 -- C14 dicarboxylic acid-based monomer units made using a nucleophilic thiol -yne polymerization methodology that targets high cis- content at comparable molar masses to provide excellent mechanical properties. As each C4 C14 dicarboxylic acid-based monomer unit contains at least Mo labile ester linkages, altering the stoichiometry of degradable C4 - C14 dicarboxylic acid-based monomer unit incorporation allows the degradation rate of the material to be tuned precisely, while retaining control over the mechanical properties by maintaining the cisltrans stereochemistry of the double bonds to provide independent tuning of mechanical and degradative properties. In one or more embodiments, these degradable C4 - C14 dicarboxylic acid-based monomers can be introduced into the thiol -yne polymerization reaction via one, or both, of the thiol and alkyne functional groups, providing additional flexibility in developing suitable polymer species.