posted on 2022-08-31, 21:45authored byLiwei Yan, Ting Zhou, Ruicheng Ni, Zhanrong Jia, Yanan Jiang, Tailin Guo, Kefeng Wang, Xian Chen, Lu Han, Xiong Lu
The
repair of cartilage damage caused by trauma, wear, or degenerative
deformation remains a major challenge in modern medicine. Therefore,
it is essential to develop a mechanically compatible and bioactive
scaffold for cartilage tissue regeneration. In this study, a mussel-inspired,
tough, adhesive polydopamine/gelatin-poly(acrylic acid) (PDA/Gel-PAA)
composite hydrogel was developed for cartilage regeneration. The hydrogel
achieved a high compressive strength of up to 0.67 MPa and a toughness
of 420 J/m2 because of the unique chemical-physical cross-linking
structure by introducing the PDA/Gel complex into the PAA network.
PAA chains with rich carboxyl groups mimic the negatively charged
glycosaminoglycans (GAGs) in the natural cartilage extracellular matrix
(ECM), leading to strong water retention in the hydrogel. The incorporation
of the PDA/Gel complex with catechol groups on PDA and arginine-glycine-aspartic
acid (RGD) sequences on gelatin chains provided abundant adhesive
motifs to improve the cell affinity and tissue adhesiveness of PAA,
thereby facilitating the adhesion and proliferation of bone marrow
stromal cells (BMSCs). In addition, transforming growth factor-β3
(TGFβ3) was stably immobilized and released from the PDA/Gel-PAA
hydrogel. Thus, adhesive hydrogels can provide a suitable microenvironment
to promote cell migration in the defect area and induce chronogenesis
for cartilage regeneration.