Cured PGS Microparticles via Sol-Gel Transition
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Solution Overview
Problem
Current methods for forming poly(glycerol sebacate) (PGS) microparticles are limited by the need for thermal processing, which causes them to melt and lose their spherical conformation, and often require photo-induced crosslinkers that can be harmful in biological systems.
Innovation Solution
A method for forming cured PGS microparticles without the use of molds or photo-induced crosslinkers, involving the combination of PGS resin with a phase-incompatible liquid that undergoes a reversible sol-gel transition, allowing for microwave or thermal curing to maintain spherical shape and prevent melting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If thermal processing is used to cure PGS microparticles, then the PGS is cured and forms a solid structure, but the microparticles melt and lose their spherical conformation
Solution Approach 1:
The patent utilizes the phase transition of a liquid support medium from liquid to gel state at a specific transition temperature. The PGS microparticles are formed in this liquid medium, then the medium is heated above its transition temperature to gelify, providing structural support during thermal curing. This allows the PGS to be cured thermally without the microparticles deforming, as the gelified medium maintains their spherical shape throughout the curing process.
2Reliability
If photo-induced crosslinkers are used to cure PGS microparticles, then the microparticles can be cured without thermal processing, but toxic by-products are generated that are harmful in biological systems
Solution Approach 1:
The patent removes photo-induced crosslinkers and initiators from the system entirely. Instead, it uses thermal curing of PGS combined with a liquid support medium that undergoes sol-gel transition. This extraction of harmful photo-initiators eliminates the generation of toxic by-products while maintaining effective curing capability through the thermal crosslinking of PGS alone.
3Reliability
If a mold is used to hold PGS resin shape during crosslinking, then the thermoset structure can be formed, but the process becomes complex and cannot produce spherical microparticles
Solution Approach 1:
The patent introduces a liquid support medium as an intermediary that temporarily holds the PGS microparticles in their spherical form. This medium acts as a sacrificial matrix that provides mechanical support during the crosslinking process. After curing is complete, the liquid medium can be removed or degraded, leaving behind the cured spherical microparticles without requiring complex molding equipment or processes.
4Ease of manufacture
If fillers are added to solidify PGS resin, then the resin can be processed without molding, but the elastomeric properties and biodegradability are compromised
Solution Approach 1:
Instead of adding fillers to solidify the PGS resin, the patent uses a liquid support medium that undergoes phase transition from liquid to gel. This gelified medium provides the necessary structural support during processing without requiring solid fillers. The medium can be chosen to be biocompatible and removable, preserving the biodegradability and elastomeric properties of the PGS while enabling mold-free processing of spherical microparticles.
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
Enables the creation of biodegradable, elastomeric microparticles with tunable degradation kinetics and controlled release properties, suitable for biomedical applications without the toxicity concerns of photo-induced initiators.
Implementation Method 1
combining the PGS resin composition with a phase-incompatible liquid that undergoes a reversible sol-gel transition
Implementation Method 2
curing the plurality of uncured microparticles to form the plurality of cured microparticles
Implementation Method 3
To create a PGS thermoset/solid structure, neat PGS resin must be crosslinked/cured at elevated temperatures
Data Source
AI summary
A method of forming cured microparticles includes providing a poly(glycerol sebacate) resin in an uncured state. The method also includes forming the composition into a plurality of uncured microparticles and curing the uncured microparticles to form the plurality of cured microparticles. The uncured microparticles are free of a photo-induced crosslinker. A method of forming a scaffold includes providing microparticles including poly(glycerol sebacate) in a three-dimensional arrangement. The method also includes stimulating the microparticles in the three-dimensional arrangement to sinter the microparticles, thereby forming the scaffold having a plurality of pores. A scaffold is formed of a plurality of microparticles including a poly(glycerol sebacate) thermoset resin in a three-dimensional arrangement. The scaffold has a plurality of pores.