Hydrogenated silicene nanosheet functionalized scaffold enables immuno‐bone remodeling

Abstract

An ideal implant needs to have the ability to coordinate the foreign body response and tissue regeneration. Here, Hydrogenated‐silicon nanosheets (H‐Si NSs) with favorable biodegradability are integrated and functionalized into a β‐tricalcium phosphate scaffold (H‐Si TCP) for bone defect healing. H‐Si TCP can greatly improve bone regeneration through osteoimmunomodulation‐guided biodegradation in vivo. The spatiotemporal regulation of degradation products replenishes sufficient nutrients step by step for the entire process of bone repair. Extracellular and intracellular reactive oxygen species (ROS) are first downregulated by reaction with H‐Si NSs, followed by marked M2 polarization, remodeling the micro‐environment timely for immune‐bone regeneration. The release of primary reaction products awakened bone marrow mesenchymal stem cells (BMSCs), which are converted into osteoblasts anchored on scaffolds. Subsequently, biomineralization is promoted by the final degradation products. The intrinsic ROS‐responsive, immunoregulatory, and osteo‐promotive capability of 2D H‐Si NSs makes such composite H‐Si TCP scaffold a highly potential alternative for the treatment of critical bone defect.

A Sonoresponsive and NIR‐II‐Photoresponsive Nanozyme for Heterojunction‐Enhanced “Three‐in‐One” Multimodal Oncotherapy

“…In addition to exploring multifunctional nanozymes with multiple enzyme-like catalytic activities, utilizing a combination of NCT with other therapeutic modalities such as photothermal therapy (PTT), photodynamic therapy (PDT), or sonodynamic therapy (SDT) is an effective strategy of achieving efficient tumor therapy. [37][38][39][40][41][42] By utilizing PTT agents with high extinction coefficient and photothermal conversion efficiency (PCE) to generate hyperthermia for ablating tumor, NIR-II PTT has been regarded as a noninvasive therapeutic modality owing to its suitable penetration depth and accurate spatial orientation. [43,44] However, the "always-on" property and the intolerable operating temperature (above 50 °C) of PTT could cause irreversible damage to the normal tissues even in the NIR-II region.…”

MXene and Xene: promising frontier beyond graphene in tissue engineering and regenerative medicine

“…Lin et al introduced a hydrogenated-Si NSs (H-Si NSs)-functionalized β-tricalcium phosphate (H-Si TCP) scaffold for use in healing bone defects. 94 Due to their capacity to scavenge excess ROS, the H-Si TCP scaffolds promoted M2 macrophage polarization, with up- and downregulation of the M2 and M1 markers, respectively. The H-Si TCP scaffolds upregulated the expression of key osteogenic markers, including BMP2, ALP, secreted phosphoprotein 1, and SP7, in the early and late stages of osteogenesis and promoted ALP activity and Ca deposition.…”

Silicon-containing nanomedicine and biomaterials: materials chemistry, multi-dimensional design, and biomedical application

“…Hydrogen-bonded silicene nanosheets (H-silicon NSs) were integrated with 3D-printed β-TCP scaffolds to form composited bone-mimetic scaffolds. 622 When the scaffolds were implanted in defect sites, the released H-silicon NSs from the composite scaffolds could scavenge the locally overproduced ROS to mitigate undesirable inflammation reactions in the early stage. Concurrently, the H-silicon NSs were endocytosed by macrophages, leading to the downregulation of the intracellular ROS levels, thereby polarizing the macrophages into the M2 phenotype.…”