Magnesium-gallate MOF integrated conductive cryogel for inflammation regulation and boosting bone regeneration

The regeneration and repair of natural bone is a complex and multifaceted process. Potentially, multifunctional scaffolds that exhibit synergistic effects of various biological activities and align with the dynamic bone healing process, are highly expected to achieve desirable bone repairing outcomes. Bioavailable magnesium (Mg) is an essential element taking part in bone regeneration via promoting angiogenesis and osteogenesis. Polyphenol gallic acid (GA) is an anti-inflammatory molecule that can modulate immune microenvironment. To control their release behaviors, Mg²⁺ and GA can react with each other to form metal-organic frameworks (MOF), which are then embedded into conductive porous scaffolds made of gelatin cryogel and poly(3,4-ethyldioxyethiophene): polystyrene sulfonate (PEDOT:PSS). In in vitro cell culture, the MOF-integrated conductive scaffold can simultaneously provide sustained supply of Mg²⁺ and GA to modulate the biological responses of a variety of cells. In in vivo evaluations, it shows remarkably enhanced new bone formation, as compared to groups of only MOF-contained non-conductive scaffold or conductive scaffold without MOF in rat calvarial defect model. In summary, conductive scaffold associated with sustained release of bioactive factors can serve as an effective treatment for inducing neo-bone growth benefiting from the synergistical contributions of diverse bioactive factors.