Alkaline phosphatase, as an enzyme involved in the process of bone mineralization and regeneration, was incorporated into a solution of SF to induce its gelation and mineralization through consecutive dephosphorylation actions on different substrates. In these processes, alkaline phosphatase firstly worked on a small peptide of NapGFFYp by removing its hydrophilic phosphate group. The resulted NapGFFY performed supramolecular assembly in the solution of SF and synergistically induced the conformation transition of SF from random coil to β-sheet structures, leading to the formation of a stable SF hydrogel under physiological conditions. And then, the entrapped ALP within the SF–NY gel network retained its catalytic activity, released phosphate ions from glycerophosphate, and catalysed the formation of calcium phosphate minerals within the porous gel. Because of the mild conditions of these processes and good biocompatibility of the scaffold, the mineralized SF gel can work as a biomimetic scaffold to promote the osteogenic differentiation of rBMSCs and stimulate femoral defect regeneration in a rat model.

中文翻译：

---

通过碱性磷酸酶的连续脱磷酸作用，用纳米晶磷酸钙陶瓷原位形成SF的多孔水凝胶，用于骨再生。

碱性磷酸酶作为一种参与骨骼矿化和再生过程的酶，被掺入SF溶液中，以通过在不同基质上连续的去磷酸化作用来诱导其凝胶化和矿化。在这些过程中，碱性磷酸酶首先通过除去NapGFFYp的亲水性磷酸基团使其作用于小肽。所得的NapGFFY在SF溶液中进行超分子组装，并协同诱导SF从无规卷曲结构转变为β-折叠结构，从而在生理条件下形成稳定的SF水凝胶。然后，残留在SF-NY凝胶网络中的ALP保留了其催化活性，从甘油磷酸中释放了磷酸根离子，并催化了多孔凝胶内磷酸钙矿物质的形成。由于这些过程的温和条件和支架的良好生物相容性，矿化的SF凝胶可以用作仿生支架，以促进rBMSC的成骨分化并刺激大鼠模型中的股骨缺损再生。