Leaf photosynthesis, coral mineralization, and trabecular bone growth depend on triply periodic minimal surfaces (TPMSs) with hyperboloidal structure on every surface point with varying Gaussian curvatures. However, translation of this structure into tissue-engineered bone grafts is challenging. This article reports the design and fabrication of high-resolution three-dimensional TPMS scaffolds embodying biomimicking hyperboloidal topography with different Gaussian curvatures, composed of body inherent β-tricalcium phosphate, by stereolithography-based three-dimensional printing and sintering. The TPMS bone scaffolds show high porosity and interconnectivity. Notably, compared with conventional scaffolds, they can reduce stress concentration, leading to increased mechanical strength. They are also found to support the attachment, proliferation, osteogenic differentiation, and angiogenic paracrine function of human mesenchymal stem cells (hMSCs). Through transcriptomic analysis, we theorize that the hyperboloid structure induces cytoskeleton reorganization of hMSCs, expressing elongated morphology on the convex direction and strengthening the cytoskeletal contraction. The clinical therapeutic efficacy of the TPMS scaffolds assessed by rabbit femur defect and mouse subcutaneous implantation models demonstrate that the TPMS scaffolds augment new bone formation and neovascularization. In comparison with conventional scaffolds, our TPMS scaffolds successfully guide the cell fate toward osteogenesis through cell-level directional curvatures and demonstrate drastic yet quantifiable improvements in bone regeneration.

Graphene has made significant contributions to neural tissue engineering due to its electrical conductivity, biocompatibility, mechanical strength, and high surface area. However, it demonstrates a lack of biological and chemical cues. Also, it may cause potential damage to the host body, limiting its achievement of efficient construction of neural tissues. Recently, there has been an increasing number of studies showing that combining graphene with other materials to form nano-composites can provide exceptional platforms for both stimulating neural stem cell adhesion, proliferation, differentiation and neural regeneration. This suggests that graphene nanocomposites are greatly beneficial in neural regenerative medicine. In this mini review, we will discuss the application of graphene nanocomposites in neural tissue engineering and their limitations, through their effect on neural stem cell differentiation and constructs for neural regeneration.

Current sprayable hydrogel masks lack the stepwise protection, cleansing, and nourishment of extensive wounds, leading to delayed healing with scarring. Here, we develop a sprayable biomimetic double wound mask (BDM) with rapid autophasing and hierarchical programming for scarless wound healing. The BDMs comprise hydrophobic poly (lactide- co –propylene glycol– co -lactide) dimethacrylate (PLD) as top layer and hydrophilic gelatin methacrylate (GelMA) hydrogel as bottom layer, enabling swift autophasing into bilayered structure. After photocrosslinking, BDMs rapidly solidify with strong interfacial bonding, robust tissue adhesion, and excellent joint adaptiveness. Upon implementation, the bottom GelMA layer could immediately release calcium ion for rapid hemostasis, while the top PLD layer could maintain a moist, breathable, and sterile environment. These traits synergistically suppress the inflammatory tumor necrosis factor–α pathway while coordinating the cyclic guanosine monophosphate/protein kinase G–Wnt/calcium ion signaling pathways to nourish angiogenesis. Collectively, our BDMs with self-regulated construction of bilayered structure could hierarchically program the healing progression with transformative potential for scarless wound healing.