Self-assembling peptide hydrogel scaffold integrating stem cell-derived exosomes for infected bone defects.

Infected bone defect (IBD) is a great challenge in orthopedics, which involves in bone loss and infection. Here, a self-assembling hydrogel scaffold (named AMP-RAD/EXO), integrating antimicrobial peptides(AMPs), RADA16 and BMSCs exosomes with an innovative strategy, is developed and applied in IBD treatment for sustained antimicrobial ability, accelerating osteoblasts proliferation and promoting bone regeneration. AMPs present an excellent ability to inhibit infection, RADA16 is a self-assembling peptide hydrogel for AMPs delivery, and BMSCs exosomes can promote the bone regeneration. The prepared AMP-RAD/EXO exhibited a polyporous 3D structure for imbibition of BMSCs exosomes and migration of osteoblasts. studies indicate AMP-RAD/EXO can inhibit the growth of accelerate the proliferation and migration of BMSCs. More importantly, results also prove that AMP-RAD/EXO exhibit an excellent effect on IBD treatment. Thus, the prepared AMP-RAD/EXO provides a multifunctional scaffold concept for bone tissue engineering technology.