Injectable and Self-Curing Single-Component Hydrogel for Stem Cell Encapsulation and In Vivo Bone Regeneration

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Tissue Engineering

Background:

• Developing injectable hydrogels is crucial for effective stem cell therapy.
• Existing hydrogels often lack the necessary properties for promoting cell proliferation and differentiation in vivo.
• Ideal hydrogels should be injectable, promote cell activity, and possess suitable mechanical properties for tissue regeneration.

Purpose of the Study:

• To develop an injectable, single-component hydrogel for stem cell therapy.
• To create a hydrogel with shear-thinning and self-curing properties for enhanced in vivo performance.
• To evaluate the hydrogel's ability to support human mesenchymal stem cell (hMSC) proliferation, differentiation, and bone regeneration.

Main Methods:

• Synthesized a hyaluronic acid (HA) based hydrogel modified with phenylboronic acid (PBA) and spermidine (SM), termed HAps.
• Investigated the hydrogel's injectable nature through shear-thinning properties and its in situ gelation via reversible PBA-diol crosslinking stabilized by SM.
• Assessed hMSC proliferation and osteogenic differentiation in vitro and evaluated bone regeneration in a rat femoral defect model in vivo.

Main Results:

• The HAps hydrogel exhibited shear-thinning behavior for syringe injectability and a post-injection self-curing property, leading to increased stiffness.
• The hydrogel demonstrated favorable proliferation of hMSCs and promoted their osteogenic differentiation and mineralization.
• In vivo studies showed efficient osteogenic differentiation of hMSCs and significant bone regeneration in rat femoral defects.

Conclusions:

• The HAps hydrogel, featuring simple cationic modification, offers efficient gelation with desirable shear-thinning and self-curing characteristics.
• This injectable hydrogel shows significant potential for advancing stem cell therapy and promoting in vivo bone regeneration.
• The developed biomaterial meets the physical requirements for stem cell therapy in rigid tissues while maintaining injectability.