A rapidly fabricated bone marrow enrichment material with a controllable pore size promotes osteogenesis close to autogenous bone graft in clinic

The shortage of highly osteogenic grafts significantly impacts clinical bone repair and reconstruction in clinic. Selective cell retention technology increases the number of bone marrow (BM)-derived osteogenic cells on scaffold materials. A suitable pore size is key for improving the efficiency of BM cell enrichment of scaffold materials. Many materials with a controllable pore size have been developed, but due to ethics policies, only a few have been approved for clinical use.

In this study, cortical bone shavings with a small pore size were mixed in different ratios with decalcified bone matrix, which has a relatively larger pore size, to form a new BM enrichment scaffold material with an adjustable pore size (MIX materials).

We evaluated the in vitro and in vivo enrichment efficiency and osteogenic ability of materials with different pore sizes.

MIX material (1:1) had suitable pore size that was beneficial for the effective enrichment of BM-derived cells and cytokines and promoted the proliferation and osteogenic differentiation of mesenchymal stem cells in vitro. A subcutaneous heterotopic transplantation experiment in a nude mouse model confirmed that MIX material enhanced osteoinductive potential and angiogenesis in vivo. Similarly, a large animal model using goats with a critical bone defect (2.5 cm) showed that the osteogenic ability of enriched MIX was superior to that of nonenriched MIX after 3 months. A subsequent self-controlled prospective clinical study demonstrated that the osteogenic ability of enriched MIX material was close to that of an autograft (the clinical gold standard) in lumbar intervertebral fusion surgery.

MIX scaffold material is an effective choice for the clinical treatment of bone repair and bone reconstruction.