Blended and Microparticle Composite Hyaluronan Hydrogels with Programmable Degradation through Selective Oxidation

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Tissue Engineering

Background:

• Hydrogels offer tunable properties for biomedical applications through chemical modification.
• Controlling hydrogel adhesion, viscoelasticity, and degradation is crucial for tissue integration and cell dynamics.
• Selective oxidation of polysaccharides generates aldehyde groups, but balancing adhesion and fragmentation is challenging.

Purpose of the Study:

• To devise a strategy for tunable hydrogel degradation and mechanical properties by combining oxidized and non-oxidized biopolymers.
• To investigate the impact of oxidation degree on hydrogel properties and degradation behavior.
• To engineer composite hydrogels with programmable degradation modes for tissue engineering.

Main Methods:

• Synthesis of tyramine-modified hyaluronan (THA) and its oxidized form (oTHA).
• Preparation of blended hydrogels and hydrogel microparticle composites using THA and oTHA.
• Evaluation of hydrogel degradation, viscoelastic properties, and network topology at varying oTHA-to-THA ratios.

Main Results:

• Increased oxidation of oTHA led to decreased molecular weight, slightly reduced storage modulus, increased brittleness, and accelerated degradation.
• Blended hydrogels maintained consistent viscoelastic properties and network topology despite varying oTHA content.
• Composite hydrogels exhibited two distinct degradation modes: collapse-type and fragmentation-type, tunable by adjusting the oTHA-to-THA ratio.

Conclusions:

• A novel strategy was developed to create tunable composite soft biomaterials with programmable degradation by blending oxidized and non-oxidized THA.
• The tunable degradation and mechanical properties of these hydrogels offer potential for advanced tissue engineering strategies.
• These materials can be used to control cell invasion, migration, and proliferation in biological applications.