Fast contact of solid-liquid interface created high strength multi-layered cellulose hydrogels with controllable size

Area of Science:

• Materials Science
• Biomaterials Engineering
• Polymer Chemistry

Background:

• Cellulose hydrogels are widely explored for various applications due to their biocompatibility and sustainability.
• Developing methods for constructing complex cellulose hydrogel architectures with enhanced mechanical properties remains a challenge.
• Existing fabrication techniques often involve multiple steps and may not offer precise control over structural features.

Purpose of the Study:

• To develop a novel, facile method for constructing onion-like and multi-layered tubular cellulose hydrogels.
• To investigate the influence of gel core shape and fabrication parameters on hydrogel morphology and properties.
• To evaluate the mechanical strength, stability, and biocompatibility of the fabricated cellulose hydrogels for potential applications.

Main Methods:

• Cellulose solutions in 7% NaOH/12% urea were prepared.
• Agarose gel rods/spheres loaded with acetic acid were used as sacrificial cores.
• Controlled contact between cellulose solution and gel cores initiated layer formation via acid-induced self-aggregation.
• Multi-step interrupted gelation was employed for fabricating multi-layered structures.
• Structural characteristics, mechanical properties, and cell viability were assessed.

Main Results:

• Novel onion-like and multi-layered tubular cellulose hydrogels were successfully fabricated for the first time.
• The process involves acid-induced cellulose self-aggregation at the solid-liquid interface.
• Hydrogel size, layer thickness, and inter-layer spacing were tunable by adjusting cellulose concentration, core diameter, and contact time.
• The resulting hydrogels exhibited excellent architectural stability, solvent resistance, high compressive strength, and good biocompatibility.
• L929 cells demonstrated successful adhesion and proliferation on and within the hydrogel structures.

Conclusions:

• A new, rapid solid-liquid interface method enables the construction of high-strength, multi-layered cellulose hydrogels.
• The fabricated hydrogels possess tunable structures and superior mechanical and biological properties.
• These cellulose hydrogels hold significant potential as advanced scaffolds for tissue engineering and cell culture carriers.