CARTILAGE REGENERATION

Paper

"Cartilage Regeneration in Preannealed Silk Elastin-Like Co-Recombinamers Injectable Hydrogel Embedded with Mature Chondrocytes in an Ex Vivo Culture Platform"

Although the use of hydrogel is the most promising biomaterial, it often lacks in rigidity and anchorage of cells when they are surrounded by synovial fluid while they are subjected to heavy loads.

Abstract

Tissue engineering for cartilage repair requires biomaterials that show rapid gelation and adequate mechanical properties. Although the use of hydrogel is the most promising biomaterial, it often lacks in rigidity and anchorage of cells when they are surrounded by synovial fluid while they are subjected to heavy loads.

We developed and produced the Silk Elastin-Like co-Recombinamer (SELR), which contains both the physical interaction from elastin motifs and from silk motifs.

Conclusions

We developed and produced the preannealed Silk Elastin co- Recombinamer (pA(EIS)2-(I5R)6), which shows unique properties as a promising candidate for tissue engineering applications.

We have focused on the need for biomaterials for cartilage repair, capable of being delivered into the area of interest, showing a rapid gelation and adequate mechanical properties when surrounded by synovial fluid.

We have set up and optimized a preannealing treatment based on the evolution of silk motifs into β-sheet structures and on the phenomenon of thermal memory.

In this study, we have carried out the physicalcharacterization of ourmaterial in order to provide adeeper insight into the material features, analyzing the contribution of each component (silk and elastin) for the cross-linking formation.

The pA(EIS)2-(I5R)6 has shown a fast gelation, improved mechanical properties, and the presence of a fibrillary structure directly after injection of the hydrogel. Moreover, culturing the hydrogel embedded with chondrocytes in the ex vivo culture platform for weeks has exhibited good biocompatibility and remarkable advantages; such as the de novo ECM formation, the absence of fibro-cartilage, and the production of hyaline cartilage.

The addition of the silk allows making hydrogels with a lower concentration, leading to larger pores, which is most likely responsible for better cell spreading and proliferation. In conclusion, the pA(EIS)2-(I5R)6 has been shown to have new outstanding properties, which make the hydrogel a promising injectable scaffold in the field of cartilage regeneration.