Xiangfeng Li

Sustained baicalin release from mesoporous silica nanoparticles (MSNs) promotes macrophage M2 polarization via PI3K/AKT/GSK3β signaling, creating an immune-instructive microenvironment for enhanced cutaneous wound healing.

Whitlockite (WH), a natural magnesium-containing calcium phosphate second in abundance only to hydroxyapatite (HAp) in the inorganic phase of bone tissue, has attracted great attention in bone repair recently. Previous studies have shown that porous structures play a pivotal role in bone defect repair using biomaterials. However, the traditional fabrication process of porous ceramic through high-temperature sintering frequently results in the dehydration and breakdown of WH. To overcome this challenge, we develop an innovative fabrication of porous whitlockite ceramic via in-situ phase transformation from calcium phosphate ceramic. Furthermore, we perform molecular dynamics (MD) and determine intermediates to delve into a comprehensive exploration of the underpinning mechanism of the transformation. In-vitro cellular responses reveal the superior cell proliferation, adhesion, spreading, migration, and osteogenic and angiogenic differentiation of porous WH ceramic. Mechanistically, our results reveal that the Mg²⁺-mediated regulation of ATP levels activates the AMPK-FoxO signaling axis, which enhances osteogenesis through autophagy. Intramuscular implantation evaluation confirms the satisfactory osteoinduction, and further rat mandibular defect implantation reveals significant bone regeneration in comparison to calcium phosphate ceramic. Together, the porous WH ceramic encompasses enhanced potential for the regenerative amelioration of bone defects.

Regenerative repair of segmental bone defect remains a major clinical challenge. The conventional mental implants suffer from mechanical strength mismatch and long‐term foreign bodies presence. While, the osteoinductive materials lack insufficient mechanical strength for the repair of load‐bearing bone. Inspired by bamboo, whisker‐reinforced Ca‐P ceramics (HW) have been developed to accelerate segmental bone regeneration. Bamboo‐like whiskers can reduce the stress concentration and impede crack propagation via whisker broken, whisker bridging, and crack deflection, achieving 3 times increase in the compressive strength compared to traditional ceramics. In addition, HW significantly promotes the formation of type‐H endothelial cells (ECs) via the integrin‐mediated HIF‐1 signaling pathway, which can secrete coupling factors (e.g. Noggin), to promote the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). In turn, HW can stimulate BMSCs to secrete coupling factors (e.g. VEGF) to support angiogenesis. In the segmental bone defect model, DFO is introduced to bamboo‐like whiskers (HW+DFO) to enhance type‐H vessels formation. HW+DFO can effectively promote the repair of segmental bone defects with mechanical recovery reaching 40% of that of normal femur. In conclusion, this study proposes a novel strategy for promoting bone regeneration by regulating type‐H vessels, offering a potential solution for addressing segmental bone defects.

Osteoporotic bone defects, characterized by chronic inflammation and impaired osteogenesis, pose a formidable challenge for functional bone regeneration. Conventional scaffolds lack effective regulation of the inflammatory microenvironment and fail to coordinate anti‐inflammatory and osteogenic signals, thereby limiting their ability to couple inflammation resolution with new bone formation. Here, we developed a “Brake–Drive Osteo System”, a spatiotemporally programmed biomaterial integrating quercetin‐loaded nanovesicles and teriparatide‐loaded nucleic acid frameworks within a calcium phosphate scaffold (BCP‐T/N@Q/V). This design enables a sequential therapeutic cascade—quercetin first “disengages the inflammatory brake”, alleviating microenvironmental resistance to osteogenesis, while teriparatide subsequently “activates the osteogenic drive”, promoting bone regeneration. It effectively reprogrammed macrophages toward a pro‐regenerative phenotype and mitigated inflammatory stress, establishing an immunologically permissive microenvironment. This osteoimmune modulation significantly enhanced the osteogenic commitment and maturation of osteoporotic bone marrow mesenchymal stem cells. In a rat osteoporotic femoral condyle defect model, the scaffold achieved accelerated, structurally integrated bone regeneration, underscoring its translational potential. Collectively, this “Brake–Drive Osteo System” provides a sequential strategy that couples inflammation resolution with osteogenesis for effective osteoporotic bone regeneration.

Topology optimization based on femoral defect mechanics is used to design Ca–P implants featuring spatially graded stochastic porosity.

The left part presents a schematic of maxillofacial tissue development (derived from neural crest cells) and the pathogenesis of alveolar cleft in CL/P, while the right part outlines the status of biomaterials for bone regeneration in CL/P.

The enhancement of the mechanical properties of hydroxyapatite (HA) bioceramics constitutes a significant research focus in the biomedical field. The present study is dedicated to the preparation of ultra‐uniform nanocrystalline HA bioceramics and their influence on the mechanical properties and biological performances. First, HA powder with a uniform dispersion was fabricated through a sequential process encompassing low‐temperature pre‐sintering, ball milling, and gradient centrifugation. Subsequently, the green body underwent the two‐step sintering and the quenching process to enhance the density and mechanical strength. The nanoceramics displayed excellent hydrophilicity and increased roughness. The nanoindentation tests revealed that the nanoceramics did not undergo any elastic‐plastic deformation, and there was no indentation size effect phenomenon. In vitro biological performances suggested that the nanoceramics have the potential to facilitate osteogenic differentiation of bone marrow mesenchymal stem cells. Therefore, it can be concluded that the construction of ultra‐uniform nanocrystalline is an effective approach to improve the mechanical and biological properties of HA bioceramics.