Water-Responsive Shape Recovery Induced Buckling in Biodegradable Photo-Cross-Linked Poly(ethylene glycol) (PEG)...

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Medical Devices

Background:

• Shape memory materials (SMMs) exhibit shape recovery upon specific stimuli.
• Hydrogels absorb water, leading to swelling and potential for stimuli-responsive effects.
• Water-responsive SMMs are promising for biomedical applications due to water's prevalence in biological systems.

Purpose of the Study:

• To investigate water-activated shape recovery induced buckling in biodegradable PEG hydrogels.
• To understand the fundamentals of precisely controlling buckling time for medical applications.
• To elucidate the molecular mechanism behind water-induced shape memory effect (SME) in PEG hydrogels.

Main Methods:

• Experimental investigation of water-activated shape recovery induced buckling.
• Analytical modeling to understand buckling dynamics.
• Simulation to confirm experimental findings and parameter influence.
• Identification of key parameters influencing shape recovery time.

Main Results:

• A biodegradable PEG hydrogel composite was developed for rapid vascular occlusion.
• The device activates within 2 minutes and completes occlusion in seconds via water-responsive shape recovery induced buckling.
• Buckling time can be precisely tailored between 1 and 4 minutes by adjusting original diameter and prestretching.
• The study elucidates the molecular mechanism of water-induced SME in PEG hydrogels.

Conclusions:

• Water-responsive shape memory hydrogels combined with swelling offer enhanced performance for applications like vascular occlusion.
• Precise control over buckling time is achievable, meeting critical time requirements for medical procedures.
• The findings on chemically induced buckling are generic and applicable to various responsive gels.