Injectable and Degradable POSS-Polyphosphate-Polysaccharide Hybrid Hydrogel Scaffold for Cartilage Regeneration

The limited self-repair capacity of articular cartilage has motivated the development of stem cell therapy based on artificial scaffolds that mimic the extracellular matrix (ECM) of cartilage tissue. In view of the specificity of articular cartilage, desirable tissue adhesiveness and stable mechanical properties under cyclic mechanical loads are critical for cartilage scaffolds. Herein, we developed an injectable and degradable organic-inorganic hybrid hydrogel as a cartilage scaffold based on polyhedral oligomeric silsesquioxane (POSS)-cored polyphosphate and polysaccharide. Specifically, acrylated 8-arm star-shaped POSS-poly(ethyl ethylene phosphate) (POSS-8PEEP-AC) was synthesized and cross linked with thiolated hyaluronic acid (HA-SH) to form a degradable POSS-PEEP/HA hydrogel. Incorporation of POSS in the hydrogel increased the mechanical properties. The POSS-PEEP/HA hydrogel showed enzymatic biodegradability and favorable biocompatibility, supporting the growth and differentiation of human mesenchymal stem cells (hMSCs). The chondrogenic differentiation of encapsulated hMSCs was promoted by loading transforming growth factor-beta 3 (TGF-beta 3) in the hydrogel. In addition, the injectable POSS-PEEP/HA hydrogel was capable of adhering to rat cartilage tissue and resisting cyclic compression. Furthermore, in vivo results revealed that the transplanted hMSCs encapsulated in the POSS-PEEP/HA hydrogel scaffold significantly improved cartilage regeneration in rats, while the conjugation of TGF-beta 3 achieved a better therapeutic effect. The present work demonstrated the potential of the injectable, biodegradable, and enhanced POSS-PEEP/HA as a scaffold biomaterial for

Automated summary

In order to address the limited self-repair capacity of articular cartilage, researchers have developed an artificial scaffold that mimics the extracellular matrix (ECM) of cartilage tissue. The scaffold is an injectable and degradable organic-inorganic hybrid hydrogel based on polyhedral oligomeric silsesquioxane (POSS)-cored polyphosphate and polysaccharide. The hydrogel demonstrates enzymatic biodegradability, favorable biocompatibility, and the ability to support cell growth and differentiation, making it a promising biomaterial for cartilage regeneration.