Ideal biomedically engineered hydrogels should imitate the physiological environment of natural bone tissue healing. The healing ability of soft tissue is stronger than that of bone tissue, thus leading to premature growth of soft tissue into the bone tissue area of the defect and resulting in poor bone tissue healing at the defect site. In addition, good cellular affinity is necessary to allow for postimplantation fusion with surrounding tissues. Inspired by the adhesion mechanism of natural mussels, a polydopamine‐polyacrylamide (PDA‐PAM) single‐network hydrogel and a PDA‐PAM/ACP hydrogel composed of amorphous hydroxyapatite (ACP) is designed to maintain sufficient free catechol groups in the hydrogel by preventing excessive oxidation of dopamine. The hydrogels are found to confer a strong healing ability without stimulation and to have cellular affinity. More notably, separation of the ACP layer and PDA‐PAM hydrogel is not easy to achieve in a synthetic hydrogel. It is found that the hydrogels (PDA‐PAM/ACP) promote bone formation. The gel up‐regulates the expression of osteogenic genes including alkaline phosphatase, runt‐related transcription factor 2, and osteocalcin. In vivo, 8‰ PDA‐PAM/ACP gel is found to effectively repair skull defects.

中文翻译：

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贻贝启发的水凝胶生物膜复合结构的集成设计，可指导骨再生

理想的生物医学工程水凝胶应模仿天然骨组织愈合的生理环境。软组织的愈合能力强于骨组织，因此导致软组织过早生长到缺损的骨组织区域，并导致缺损部位的骨组织愈合不良。另外，良好的细胞亲和力对于允许植入后与周围组织融合是必需的。受天然贻贝的粘附机制的启发，聚多巴胺-聚丙烯酰胺（PDA-PAM）单网络水凝胶和由无定形羟基磷灰石（ACP）组成的PDA-PAM / ACP水凝胶旨在通过防止水凝胶保持足够的游离儿茶酚基团多巴胺的过度氧化。发现水凝胶在没有刺激的情况下具有很强的愈合能力，并具有细胞亲和力。更值得注意的是，在合成水凝胶中不容易实现ACP层和PDA-PAM水凝胶的分离。发现水凝胶（PDA-PAM / ACP）促进骨形成。凝胶上调了成骨基因的表达，包括碱性磷酸酶，矮子相关转录因子2和骨钙素。在体内，发现8‰PDA-PAM / ACP凝胶可有效修复颅骨缺损。