Engineering BPQDs/PLGA nanospheres-integrated wood hydrogel bionic scaffold for combinatory bone repair and osteolytic tumor therapy

Bone regeneration following the removal of tumor tissues remains a major clinical challenge for the treatment of bone defects, in which materials with combinatory bone repair and osteolytic metastasis therapy is considered as a promising solution. Herein, a highly strong delignified wood/regenerated silk fibroin (RSF) hydrogel scaffold integrated with black phosphorus quantum dots (BPQDs) encapsulated by poly (lactic-co-glycolic acid) (PLGA) was engineered to realize efficient mechanical supporting, bone regeneration, and tumor therapy. Following delignification, the white wood (WW) scaffold significantly improved the mechanical properties of RSF composite hydrogel, with the elastic modulus in the L-direction and R-direction of 300 MPa and 3.3 MPa, and compression modulus in the L-direction of 9.3 MPa. Moreover, the WW/RSF hydrogel scaffold with BPQD/PLGA nanospheres effectively promoted the proliferation, migration, and osteogenic differentiation of bone mesenchymal stem cells and enhanced osteogenesis in vivo. Compared with the vertical implantation method, better bone regeneration was observed in parallel implantation system parallel to bone shaft. Importantly, the BPQDs in the hydrogel scaffolds could inhibit osteoclast differentiation and exhibit photothermal effects against metastatic tumor in the spine. Our data provide promising evidence for the potential therapeutic application on bone regeneration and ablation of bone metastasis.