Cartilage is one of our body’s tissues which are not repaired automatically by itself. Problems associated with cartilage are very common worldwide and are considered the leading cause of pain and disability. Smart biomaterial or “Four dimensional” (4D) biomaterials has started emerging as a suitable candidate, which are principally three dimensional (3D) materials that change their morphology or generate a response measured at space and time to physiologic stimuli. In this context, the release of oxygen through hydrogels in contact with water is considered as 4D biomaterials. The objective of this study is to develop strategies to release oxygen in a sustainable and prolonged manner through hydrogels systems to promote chondrocytes survival in oxygen-free environment. The 4D biomaterials are engineered from gelatin methacryloyl (GelMA) loaded with calcium peroxide (CPO), which have the ability to generate oxygen in a controlled and sustained manner for up to 6 days. The incorporation of CPO into the hydrogel system provided materials with enhanced mechanical and porosity properties. Furthermore, the hydrogels promoted chondrocyte survival and reduced cell death under oxygen-free conditions.

软骨是人体自身无法自动修复的组织之一。与软骨有关的问题在世界范围内非常普遍，被认为是导致疼痛和残疾的主要原因。智能生物材料或“四维”（4D）生物材料已开始作为合适的候选材料出现，它们主要是三维（3D）材料，这些材料会改变其形态或在时空上对生理刺激产生响应。在这种情况下，通过与水接触的水凝胶释放的氧气被认为是4D生物材料。这项研究的目的是制定策略，通过水凝胶系统以可持续和长期的方式释放氧气，以促进软骨细胞在无氧环境中的存活。4D生物材料由负载有过氧化钙（CPO）的明胶甲基丙烯酰基（GelMA）制成，该材料具有以受控和持续方式产生氧气长达6天的能力。将CPO掺入水凝胶体系为材料提供了增强的机械性能和孔隙率特性。此外，在无氧条件下，水凝胶可促进软骨细胞存活并减少细胞死亡。