An Alkaline Based Method for Generating Crystalline, Strong, and Shape Memory Polyvinyl Alcohol Biomaterials

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Materials Engineering

Background:

• Developing strong, stretchable, durable, and shape-memory biomaterials is crucial for advanced biomedical devices, tissue engineering, and soft robotics.
• Conventional methods for creating polyvinyl alcohol (PVA) hydrogels, such as freeze-thaw and chemical crosslinking, often struggle to achieve a balance of high mechanical strength and tunable properties.

Purpose of the Study:

• To introduce an innovative method for producing physically crosslinked PVA hydrogels with enhanced mechanical properties and shape memory effects.
• To explore the potential of these PVA hydrogels in various biomedical applications through in vitro and in vivo assessments.

Main Methods:

• Inducing crystallinity in dense PVA polymer by applying high-concentration sodium hydroxide.
• Characterizing the mechanical properties, water content, and shape memory behavior of the developed PVA hydrogels.
• Evaluating cytocompatibility, antifouling properties, hemocompatibility, and overall biocompatibility.
• Demonstrating fabrication techniques for PVA-based catheters, injectable electronics, and microfluidic devices using layer-by-layer and 3D printing.

Main Results:

• The developed PVA hydrogels exhibit high mechanical strength, low water content, and resistance to injury.
• The hydrogels demonstrate significant shape memory properties, recovering 90% of plastic deformation upon water exposure and generating substantial contraction force.
• In vitro and in vivo studies confirmed the material's cytocompatibility, antifouling, hemocompatibility, and biocompatibility.
• Successful fabrication of various devices, including catheters, injectable electronics, and microfluidic devices, was achieved.

Conclusions:

• The sodium hydroxide-induced gelation method offers a facile approach to creating physically crosslinked PVA hydrogels with superior mechanical and shape memory characteristics.
• The developed PVA biomaterial shows great promise for diverse biomedical applications due to its excellent performance and biocompatibility.
• This gelation strategy is versatile, supporting both layer-by-layer and 3D printing fabrication methods for advanced material design.