Boqing Zhang

The repair of critical-sized bone defects remains a formidable clinical challenge, where coordinated neurovascular reconstruction is important for effective bone regeneration. Accordingly, this study aimed to develop a three-dimensional (3D)-printed hydroxyapatite (HAp) scaffold integrating a polydopamine (PDA)-derived conductive carbon interface with Li+ release, and to evaluate its neural-, vascular-, and osteogenic-related effects in vitro and its bone-regenerative performance in vivo. A lithium-containing, hydrothermally carbonized HAp scaffold (HAp@C/Li) was fabricated through 3D printing, Li+-assisted dopamine coating, and hydrothermal carbonization. Material characterization confirmed a PDA-derived carbon coating with measurable local surface conductivity and Li+ release characterized by an early release phase followed by a gradual plateau. In vitro experimental results revealed that HAp@C/Li possessed excellent cytocompatibility. It effectively promoted neurite outgrowth of dorsal root ganglion (DRG) neurons, migration and tube formation of human umbilical vein endothelial cells (HUVECs), as well as osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). In vivo evaluation in a rat femoral condyle defect model showed favorable bone repair, collagen deposition, vascular remodeling, and neural-associated tissue responses, with significantly higher BMD at 8 weeks, whereas BV/TV did not differ significantly from that of the HAp group. Collectively, these results indicate that the HAp@C/Li scaffold provides a promising therapeutic strategy for the clinical repair of critical-sized bone defects.

A major challenge in auricular reconstruction is the endochondral ossification of engineered cartilage after subcutaneous implantation. To overcome this, we developed a functionally tailored, hybrid hydrogel scaffold that integrates anti‐angiogenic therapy with biomimetic architecture to stabilize the chondrogenic phenotype. The core consists of a DLP‐printed, bevacizumab‐eluting pNAGA‐GT hydrogel framework with 200‐µm resolution, exhibiting a compressive modulus of 5.35 MPa and a tensile modulus of 0.34 MPa, providing robust mechanical support. Sustained bevacizumab release suppresses local angiogenic activity and is accompanied by increased TIMP3 and reduced MMP9/MMP13 expression, thereby contributing to cartilage matrix preservation and reduced ossification. Encapsulating this core, a visible‐light–crosslinked GelMA‐Tyr hydrogel creates a soft (∼15 kPa), degradable (60‐day) microenvironment that spatially organizes chondrocytes and perichondrium‐derived stem/progenitor cells (PSPCs) into a cartilage‐mimetic construct, thereby preserving cell viability and chondrogenic function. This dual‐phase design enables the generation of stable, multilayered ectopic cartilage, offering a clinically translatable strategy for microtia reconstruction.

Diabetic wound healingAC: remains challenging due to persistent inflammation, oxidative stress, and impaired macrophage polarization. Herein, a multifunctional hydrogel dressing was constructed from carboxymethyl chitosan and oxidized dextran as the dynamic network, incorporating CeO2 nanozymes for early anti-inflammatory and antioxidant effects and PLGA microspheres loaded with astragaloside IV for sustained pro-regeneration. Via Schiff base crosslinking, this hydrogel self-assembled rapidly at room temperature and adhered tightly to tissue. In vitro, the hydrogel exhibited excellent biocompatibility, potent antioxidant and anti-inflammatory activities, and promoted endothelial cell migration and angiogenesis. In a diabetic rat full-thickness wound model, this hydrogel dressing effectively reduced local inflammation, drove macrophage polarization toward the M2 phenotype, and enhanced neovascularization to accelerate wound closure. RNA sequencing further revealed that inflammatory pathways, including TNF and IL-17 signaling, were suppressed while tissue regeneration programs were activated. This stepwise therapeutic strategy offers a promising alternative for diabetic wound repair.

Regeneration of large segmental bone defects remains a formidable challenge, mainly due to the lack of a supportive microenvironment for the host's intrinsic repair cascade. Although 3D‐printed porous calcium phosphate ceramics have osteoconductive properties, their inability to actively regulate key immune processes and compromised mechanical strength caused by porosity greatly limit therapeutic efficacy. Herein, an “osteoimmunology”‐informed design of a near‐infrared (NIR)‐responsive 3D‐printed gradient scaffold is proposed for intelligent bone regeneration by temporally modulating macrophage phenotypic polarization. Fabricated via digital light processing (DLP) printing combined with secondary sintering, this scaffold has a core–shell‐like gradient structure (dense interior, porous exterior), achieving a balanced combination of mechanical robustness and bioactivity. Manganese iron Prussian blue analogue (MnFePBA) nanozymes were incorporated onto the scaffold surface. Under NIR irradiation, MnFePBA not only scavenges excessive reactive oxygen species (ROS) but also triggers controlled release of Mn ^{2 +} , synergistically driving macrophages to polarize from proinflammatory M1 to proregenerative M2 phenotype. In vitro and in vivo studies confirm that the scaffold alleviates post‐implantation oxidative stress, fosters a favorable immune microenvironment, and significantly enhances bone repair, establishing a new paradigm for developing next‐generation smart bone grafts via active immunomodulation.

Porous calcium phosphate ceramics have attracted widespread attention owing to their excellent bioactivity. However, their poor mechanical properties severely limit their clinical applications. Significantly improving the mechanical strength of porous CaP ceramics while maintaining their bioactivity remains a major challenge. To address this issue, calcium sulfate is used to regulate the directional growth of hydroxyapatite grains during ceramic sintering. The in situ oriented grains can not only alleviate the stress concentration but also strengthen the bonding force between the ceramic grain boundaries. Calcium sulfate improves the release of active calcium ions from calcium phosphate ceramics, further enhancing their bioactivity and osteoinductivity in vivo. Transcriptome and proteome sequencing reveals that the in situ whisker‐reinforced ceramics increase the expression of proteins related to calcium ion binding and promote the expression of osteogenesis‐related proteins. In the supercritical bone defect repair model, repair of the defect is achieved within 3 months, with mechanical recovery reaching more than 70% of the autologous bone.

Integrated optical filter based on microring resonators plays a critical role in many applications, ranging from wavelength division multiplexing and switching to channel routing. Bandwidth tunable filters are capable of meeting the on-demand flexible operations in complex situations, due to their advantages of scalability, multi-function, and energy-saving. It has been investigated recently that parity-time (PT) symmetry coupled-resonant systems can be applied to the bandwidth-tunable filters. However, due to the trade-off between the bandwidth-tunable contrast ratio and insertion loss of system, the bandwidth-tunable contrast ratio of this method is severely limited. Here, the bandwidth-tunable contrast ratio is defined as the maximum bandwidth divided by the minimum bandwidth. In this work, we show that high bandwidth-tunable contrast ratio and low insertion loss of system can be achieved simultaneously by increasing the coupling strength between the input port and the resonant. System characterizations under different coupling states reveal that the low insertion loss can be obtained when the system initially operates at the over-coupling condition. A high bandwidth-tunable contrast ratio PT-symmetry band-pass filter with moderate insertion loss is shown on the Silicon platform. Our scheme provides an effective method to reduce the insertion loss of on-chip tunable filters, which is also applicable to the high-order cascaded microring systems.