Bioorthogonal Suzuki-Miyaura Cross-linking: Transforming Responsive Hydrogels into Permanent Polymer Networks.

Area of Science:

• Polymer Chemistry
• Biomaterials Science
• Organic Synthesis

Background:

• Reversible polymer networks offer tunable properties but often lack long-term stability.
• Injectable hydrogels based on reversible bonds (e.g., boronate esters) are useful but can degrade or change properties undesirably.
• Developing methods to permanently stabilize these networks is crucial for reliable biomedical applications.

Purpose of the Study:

• To develop a novel strategy for converting reversible polymer networks into stable, nonresponsive networks.
• To utilize bio-orthogonal Suzuki-Miyaura coupling (SMC) for irreversible cross-linking.
• To create robust polymer networks with enhanced stability and hemocompatibility for biomedical applications.

Main Methods:

• Synthesized a responsive precursor from sodium alginate modified with phenyl boronic acid.
• Utilized boronic acids to form reversible boronate esters with cis-diols for initial gelation.
• Employed bio-orthogonal Suzuki-Miyaura coupling (SMC) with iodide-functionalized molecules to form stable carbon-carbon bonds, irreversibly cross-linking the network.
• Characterized the mechanical stability, responsiveness (pH, temperature), degradation resistance, and hemocompatibility of the resulting networks.

Main Results:

• Successfully converted reversible polymer networks into stable, nonresponsive networks using bio-orthogonal SMC.
• The resulting networks demonstrated robust mechanical stability and minimal sensitivity to pH and temperature changes.
• Achieved high resistance to degradation and excellent hemocompatibility.
• Demonstrated the versatility of SMC for transforming polymer network properties.

Conclusions:

• Bio-orthogonal Suzuki-Miyaura coupling is a potent strategy for the irreversible stabilization of polymer networks.
• The developed approach enables the transformation of responsive polymer gels into stable, nonresponsive materials.
• The resulting stable networks possess desirable properties for advanced biomedical applications, including enhanced durability and hemocompatibility.