Construction\nof Nanohydroxyapatite/Poly(sodium lipoate)-Based\nBioactive Hydrogels for Cranial Bone Regeneration

Persistent oxidative stress following bone defects significantly\nimpedes the repair of bone tissue. Designing an antioxidative hydrogel\nwith a suitable mechanical strength can help alter the local microenvironment\nand promote bone defect healing. In this work, α-lipoic acid\n(LA), a natural antioxidant small molecule, was chemically cross-linked\nwith lipoic acid-functionalized poly(ethylene glycol) (PEG<sub><i>x</i></sub>, <i>x</i> = 6k or 10k) in sodium bicarbonate\nsolution, to prepare LA-PEG<sub><i>x</i></sub> hydrogels\n(LP<sub><i>x</i></sub>, <i>x</i> = 6k or 10k).\nFurthermore, nanohydroxyapatite (nHA)-LA-PEG<sub><i>x</i></sub> (HLP<sub><i>x</i></sub>, <i>x</i> = 6k)\nhydrogels were constructed through incorporating nHA. The hydrogels\nexhibited moderate mechanical strength, facile injectability, self-healability,\nadhesion, biodegradability, biocompatibility, and promising antioxidation\nefficiency. We verify the advantage of the HLP<sub>6k</sub>-3 hydrogel\nin a rat cranial defect model. Through the regulation of reactive\noxygen species (ROS), osteoconduction, and biomineralization capabilities,\nour system can promote new bone formation. Overall, bioactive hydrogels\nwith multiple functions hold significant promise for repairing bone\ndefects.