3D Printing Hydrogel Scaffolds with Nanohydroxyapatite Gradient to Effectively Repair Osteochondral Defects in Rats

Osteochondral (OC) defects pose an enormous challenge with no entirely satisfactory repair strategy to date. Herein, a 3D printed gradient hydrogel scaffold with a similar structure to that of OC tissue is designed, involving a pure hydrogel-based top cartilage layer, an intermediate layer for calcified cartilage with 40% (w w⁻¹) nanohydroxyapatite (nHA) and 60% (w w⁻¹) hydrogel, and a 70/30% (w w⁻¹) nHA/hydrogel-based bottom subchondral bone layer. This study is conducted to evaluate the efficacy of the scaffold with nHA gradients in terms of its ability to promote OC defect repair. The fabricated composites are evaluated for physicochemical, mechanical, and biological properties, and then implanted into the OC defects in 56 rats. Overall, bone marrow stromal cells (BMSCs)-loaded gradient scaffolds exhibit superior repair results as compared to other scaffolds based on gross examination, micro-computed tomography (micro-CT), as well as histologic and immunohistochemical analyses, confirming the ability of this novel OC graft to facilitate simultaneous regeneration of cartilage-subchondral bone.     

Integrated and Bifunctional Bilayer 3D Printing Scaffold for Osteochondral Defect Repair

Bioinspired scaffolds with two distinct regions resembling stratified anatomical architecture provide potential strategies for osteochondral defect repair and are studied in preclinical animals. However, delamination of the two layers often causes tissue disjunction between the regenerated cartilage and subchondral bone, leading to few commercially available clinical applications. This study develops an integrated poly(ε-caprolactone) (PCL)-based scaffold for repairing osteochondral defects. An extracellular matrix (ECM)-incorporated 3D printing composite scaffold (ECM/PCL) coated with ECM hydrogel (E-co-E/PCL) is fabricated as the upper layer, and magnesium oxide nanoparticles coated with polydopamine (MgO@PDA)-incorporated composite scaffold (MD/PCL) is fabricated using 3D printing as the bottom layer. The physicochemical and mechanical properties of the bilayer scaffold meet the requirements in designing and fabricating the osteochondral scaffold, especially a strong interface possessed between the two layers. By in vitro study, the integrated scaffold stimulates proliferation, chondrogenic differentiation, and osteogenic differentiation of human bone mesenchymal stem cells. Moreover, the integrated bilayer scaffold exhibits well repair ability to facilitate simultaneous regeneration of cartilage and subchondral bone after implanting into the osteochondral defect in rats. In addition, cartilage “tidemarks” completely regenerated after 12 weeks of implantation of the bilayer scaffold, which indicates no tissue disjunctions formed between the regenerated cartilage and subchondral bone.     

Bioprinted Scaffold Remodels the Neuromodulatory Microenvironment for Enhancing Bone Regeneration

Herein, a 3D bioprinted scaffold is proposed, containing a calcitonin gene-related peptide (CGRP) and the β-adrenergic receptor blocker propranolol (PRN) as a new method to achieve effective repair of bone defects. By leveraging the neuromodulation mechanism of bone regeneration, CGRP and PRN loaded mesoporous silica nanoparticles are added into a hybrid bio-ink, which initially contains gelatin methacrylate, Poly (ethylene glycol) diacrylate and bone marrow mesenchymal stem cells (BMSCs). Subsequently, the optimized bio-ink is used for 3D bioprinting to create a composite scaffold with a pre-designed micro-nano hierarchical structure. The migration and tube formation of human umbilical vein endothelial cells (HUVECs) can be promoted by the scaffold, which is beneficial to the formation of a new capillary network during the bone repair process. With the release of CGRP from the scaffold, the secretion of neuropeptides by sensory nerves is simulated. Meanwhile, the release of PRN can inhibit the binding process of catecholamine to β-adrenergic receptor, co-promoting the osteogenic differentiation of BMSCs with CGRP and silicon ions, which will effectively enhance bone repair of a critical-sized cranial defect in a rat model. In conclusion, this study provides a promising strategy for bone defect repair by understanding the neuromodulatory mechanisms during bone regeneration.     

Engineered Vascularized Flaps,Composed of Polymeric Soft Tissue and Live Bone,Repair Complex Tibial Defects

Functional regeneration of complex large-scaled defects requires both soft- and hard-tissue grafts. Moreover, bone constructs within these grafts require an extensive vascular supply for survival and metabolism during the engraftment. Soft-tissue pedicles are often used to vascularize bony constructs. However, extensive autologous tissue-harvest required for the fabrication of these grafts remains a major procedural drawback. In the current work, a composite flap is fabricated using synthetic soft-tissue matrices and decellularized bone, combined in vivo to form de novo composite tissue with its own vascular supply. Pre-vascularization of the soft-tissue matrix using dental pulp stem cells (DPSCs) and human adipose microvascular endothelial cells (HAMECs) enhances vascular development within decellularized bones. In addition, osteogenic induction of bone constructs engineered using adipose derived mesenchymal stromal cells positively affects micro-capillary organization within the mineralized component of the neo-tissue. Eventually, these neo-tissues used as axial reconstructive flaps support long-term bone defect repair, as well as muscle defect bridging. The composite flaps described here may help eliminate invasive autologous tissue-harvest for patients in need of viable grafts for transplantation.     

Bioinspired Highly Anisotropic,Ultrastrong and Stiff,and Osteoconductive Mineralized Wood Hydrogel Composites for Bone Repair

Anisotropic hydrogels mimicking the biological tissues with directional functions play essential roles in damage-tolerance, cell guidance and mass transport. However, conventional synthetic hydrogels often have an isotropic network structure, insufficient mechanical properties and lack of osteoconductivity, which greatly limit their applications for bone repair. Herein, inspired by natural bone and wood, a biomimetic strategy is presented to fabricate highly anisotropic, ultrastrong and stiff, and osteoconductive hydrogel composites via impregnation of biocompatible hydrogels into the delignified wood followed by in situ mineralization of hydroxyapatite (HAp) nanocrystals. The well-aligned cellulose nanofibrils endow the composites with highly anisotropic structural and mechanical properties. The strong intermolecular bonds of the aligned cellulose fibrils and hydrogel/wood interaction, and the reinforcing nanofillers of HAp enable the composites remarkable tensile strength of 67.8 MPa and elastic modulus of 670 MPa, three orders of magnitude higher than those of conventional alginate hydrogels. More importantly, the biocompatible hydrogel together with aligned HAp nanocrystals could effectively promote osteogenic differentiation in vitro and induce bone formation in vivo. The bone ingrowth into the hydrogel composite scaffold also yields good osteointegration. This study provides a low-cost, eco-friendly, feasible, and scalable approach for fabricating anisotropic, strong, stiff, hydrophilic, and osteoconductive hydrogel composites for bone repair.     

Enhanced Physiochemical and Mechanical Performance of Chitosan‐Grafted Graphene Oxide for Superior Osteoinductivity

The regeneration of artificial bone substitutes is a potential strategy for repairing bone defects. However, the development of substitutes with appropriate osteoinductivity and physiochemical properties, such as water uptake and retention, mechanical properties, and biodegradation, remains challenging. Therefore, there is a motivation to develop new synthetic grafts that possess good biocompatibility, physiochemical properties, and osteoinductivity. Here, we fabricate a biocompatible scaffold through the covalent crosslinking of graphene oxide (GO) and carboxymethyl chitosan (CMC). The resulting GO‐CMC scaffold shows significant high water retention (44% water loss) compared with unmodified CMC scaffolds (120% water loss) due to a steric hindrance effect. The modulus and hardness of the GO‐CMC scaffold are 2.75‐ and 3.51‐fold higher, respectively, than those of the CMC scaffold. Furthermore, the osteoinductivity of the GO‐CMC scaffold is enhanced due to the π–π stacking interactions of the GO sheets, which result in striking upregulation of osteogenesis‐related genes, including osteopontin, bone sialoprotein, osterix, osteocalcin, and alkaline phosphatase. Finally, the GO‐CMC scaffold exhibits excellent reparative effects in repairing rat calvarial defects via the synergistic effects of GO and bone morphogenetic protein‐2. This study provides new insights for developing bone substitutes for tissue engineering and regenerative medicine.     

Bionic Mineralized 3D-Printed Scaffolds with Enhanced In Situ Mineralization for Cranial Bone Regeneration

In situ mineralization is a promising strategy to mimic the physicochemical properties of biominerals and is widely applied in the field of bone repair. Given the high requirement for substance exchange in cranial bone regeneration, in situ mineralized organic–inorganic hybrid materials exhibit advantages. However, the integration of remarkable mineral content, mechanical properties, and osteogenic properties also remains a major challenge. Herein, enhanced in situ mineralization through combining the enzymatic and anion-boosted mineralization is applied to promote the mineralization efficiency, mineral content, and mechanical properties. Based on the results of computational calculations and in vitro mineralization experiments, the mechanism of mineralization enhancement is investigated from the perspectives of nucleation sites and the saturation of in situ mineralization. Anionic polyaspartic acid (pAsp) can increase the saturation of in situ mineralization; enzymatic mineralization shows high efficiency, with minerals of low crystallinity. The changes in the properties of the minerals effectively enhance the biological properties of 3D-printed scaffolds, as confirmed by cell proliferation/differentiation experiments in vitro and in cranial bone regeneration in vivo. This strategy provides a new thinking for the preparation of bionic mineralized scaffolds for cranial bone repair, and can greatly promote the efficiency of bone regeneration.     

Magnesium Gradient-Based Hierarchical Scaffold for Dual-Lineage Regeneration of Osteochondral Defect

Osteochondral regeneration remains a great challenge due to the limited self-healing ability and the complexity of its hierarchical structure and composition. Mg²⁺ and hypoxia are two effective modulators in boosting chondrogenesis. To this end, a double-layered scaffold (D) consisting of a hydrogel layer on a porous cryogel is fabricated to mimic the hierarchical structure of osteochondral tissue. An Mg²⁺ gradient is incorporated into the double-layered scaffold with hypoxia-mimicking deferoxamine (DFO) embedded in the hydrogel (D-Mg-DFO), which remarkably augments the dual-lineage regeneration of both cartilage and subchondral bone. The higher Mg²⁺ supplementation from the upper hydrogel, associated with its hypoxia-mimicking situation and small pore size, exhibits promotive effects on chondrogenic differentiation. The lower Mg²⁺ supplementation from the bottom cryogel, associated with its interconnected macroporous structure, achieves multiple contributions in stem cell migration from bone marrow cavity, matrix mineralization, and osteogenesis. Furthermore, rabbits’ trochlea osteochondral defects are established to evaluate the regenerative outcome. Compared to control scaffolds containing only Mg²⁺ or DFO, the D-Mg-DFO scaffold presents the best regenerative effect under the synergistic contribution of multiple factors. Overall, this work provides a new design of scaffold toward an effective repair of cartilage defect.     

Nanofibrillar Decellularized Wharton's Jelly Matrix for Segmental Tracheal Repair

Wharton's jelly (WJ) is considered a potential scaffold in tissue‐engineered trachea for its similar composition and function to cartilage tissue. However, the feasibility of using WJ to construct engineered neocartilage tissue has not been reported, let alone tubular tracheal cartilage regeneration and segmental tracheal lesion repair. Here, electrospun nanofibrous membranes composed of three different decellularized WJ matrix (DWJM)/poly(ε‐caprolactone) (PCL) ratios (8:2, 5:5, and 2:8) are fabricated. The results demonstrate improved degradation speed, absorption, and cell adhesion capacity but weakened mechanical properties with increased DWJM content, but satisfactory homogeneous cartilage regeneration is only achieved in the DWJM/PCL (8:2) group after 12 weeks in vivo culture. Furthermore, homogeneous, 3D, tubular, trachea‐shaped cartilage is constructed with a controllable lumen diameter and wall thickness based on the 2D nanofibrous membrane using a modified sandwich model, in which the chondrocyte‐membrane construct is rolled around a silicon tube. Most importantly, by combining the above schemes with previously established vascularization and epithelialization techniques, chondrification, vascularization, and epithelialization are achieved simultaneously thus realizing long‐term (6 months) circumferential tracheal lesion repair in a rabbit model with a biological structure and function similar to that of native trachea, representing a promising approach for the clinical application of tracheal tissue engineering.     

3D Printing of Bilineage Constructive Biomaterials for Bone and Cartilage Regeneration

Owing to the different biological properties of articular cartilage and subchondral bone, it remains significant challenge to construct a bi‐lineage constructive scaffold. In this study, manganese (Mn)‐doped β‐TCP (Mn‐TCP) scaffolds with varied Mn contents are prepared by a 3D‐printing technology. The effects of Mn on the physicochemical properties, bioactivity, and corresponding mechanism for stimulating osteochondral regeneration are systematically investigated. The incorporation of Mn into β‐TCP lowers the lattices parameters and crystallization temperatures, but improves the scaffold density and compressive strength. The ionic products from Mn‐TCP significantly improve the proliferation of both rabbit chondrocytes and mesenchymal stem cells (rBMSCs), as well as promote the differentiation of chondrocytes and rBMSCs. The in vivo study shows that Mn‐TCP scaffolds distinctly improve the regeneration of subchondral bone and cartilage tissues as compared to TCP scaffolds, upon transplantation in rabbit osteochondral defects for 8 and 12 weeks. The mechanism is closely related to the Mn²⁺ ions significantly stimulated the proliferation and differentiation of chondrocytes through activating HIF pathway and protected chondrocytes from the inflammatory osteoarthritis environment by activating autophagy. These findings suggest that 3D‐printing of Mn‐containing scaffolds with improved physicochemical properties and bilineage bioactivities represents an intelligent strategy for regenerating osteochondral defects.     

Programmable Electrofabrication of Porous Janus Films with Tunable Janus Balance for Anisotropic Cell Guidance and Tissue Regeneration

Janus films with controlled pore structures can be particularly important in diverse applications. There remains a challenge for simple, rapid, and scalable fabrication methods to control Janus balance (JB) including the thickness of the individual face as well as porosity and pore size. Here the electrofabrication of a porous Janus film with controlled Janus balance from aminopolysaccharide chitosan under the salt effect is reported. Sequential deposition of chitosan under programmable salt environment and electrochemical conditions enables construction of Janus films with precisely controlled Janus balance. Bioactive partially soluble calcium phosphate (CaP) salts can also generate porous structure in Janus film. It is specifically reported that a chitosan/hydroxyl apatite (HAp) composite Janus film can serve as an effective scaffold for guided bone regeneration. The dense layer functions to provide mechanical support and serves as a barrier for fibrous connective tissue penetration. The porous composite layer functions to provide the microenvironment for osteogenesis. In vivo studies using a rat calvarial defect model confirm the beneficial features of this Janus composite for guided bone regeneration. These results suggest the potential of electrofabrication as a simple and scalable platform technology to tune the self‐organization of soft matter for a range of emerging applications.     

Biomimetic Structures: Biological Implications of Dipeptide‐Substituted Polyphosphazene–Polyester Blend Nanofiber Matrices for Load‐Bearing Bone Regeneration

Successful bone regeneration benefits from three‐dimensional (3D) bioresorbable scaffolds that mimic the hierarchical architecture and mechanical characteristics of native tissue extracellular matrix (ECM). A scaffold platform that integrates unique material chemistry with nanotopography while mimicking the 3D hierarchical bone architecture and bone mechanics is reported. A biocompatible dipeptide polyphosphazene‐polyester blend is electrospun to produce fibers in the diameter range of 50–500 nm to emulate dimensions of collagen fibrils present in the natural bone ECM. Various electrospinning and process parameters are optimized to produce blend nanofibers with good uniformity, appropriate mechanical strength, and suitable porosity. Biomimetic 3D scaffolds are created by orienting blend nanofiber matrices in a concentric manner with an open central cavity to replicate bone marrow cavity, as well as the lamellar structure of bone. This biomimicry results in scaffold stress–strain curve similar to that of native bone with a compressive modulus in the mid‐range of values for human trabecular bone. Blend nanofiber matrices support adhesion and proliferation of osteoblasts and show an elevated phenotype expression compared to polyester nanofibers. Furthermore, the 3D structure encourages osteoblast infiltration and ECM secretion, bridging the gaps of scaffold concentric walls during in vitro culture. The results also highlight the importance of in situ ECM secretion by cells in maintaining scaffold mechanical properties following scaffold degradation with time. This study for the first time demonstrates the feasibility of developing a mechanically competent nanofiber matrix via a biomimetic strategy and the advantages of polyphosphazene blends in promoting osteoblast phenotype progression for bone regeneration.     

Hybrid Materials from Ultrahigh‐Inorganic‐Content Mineral Plastic Hydrogels: Arbitrarily Shapeable,Strong, and Tough

Natural mineralized structural materials such as nacre and bone possess a unique hierarchical structure comprising both hard and soft phases, which can achieve the perfect balance between mechanical strength and shape controllability. Nevertheless, it remains a great challenge to control the complex and predesigned shapes of artificial organic–inorganic hybrid materials at ambient conditions. Inspired by the plasticity of polymer‐induced liquid precursor phases that can penetrate and solidify in porous organic frameworks for biomineral formation, here a mineral plastic hydrogel is shown with ultrahigh silica content (≈95 wt%) that can be similarly hybridized into a porous delignified wood scaffold, and the resultant composite hydrogels can be manually made into arbitrary shapes. Subsequent air drying well preserves the designed shapes and produces fire‐retardant, ultrastrong, and tough structural organic–inorganic hybrids. The proposed mineral plastic hydrogel strategy opens an easy and eco‐friendly way for fabricating bioinspired structural materials that compromise both precise shape control and high mechanical strength.     

A Bi‐Lineage Conducive Scaffold for Osteochondral Defect Regeneration

Because cartilage and bone tissues have different lineage‐specific biological properties, it is challenging to fabricate a single type of scaffold that can biologically fulfill the requirements for regeneration of these two lineages simultaneously within osteochondral defects. To overcome this challenge, a lithium‐containing mesoporous bioglass (Li‐MBG) scaffold is developed. The efficacy and mechanism of Li‐MBG for regeneration of osteochondral defects are systematically investigated. Histological and micro‐CT results show that Li‐MBG scaffolds significantly enhance the regeneration of subchondral bone and hyaline cartilage‐like tissues as compared to pure MBG scaffolds, upon implantation in rabbit osteochondral defects for 8 and 16 weeks. Further investigation demonstrates that the released Li+ ions from the Li‐MBG scaffolds may play a key role in stimulating the regeneration of osteochondral defects. The corresponding mechanistic pathways involve Li+ ions enhancing the proliferation and osteogenic differentiation of bone mesenchymal stem cells (BMSCs) through activation of the Wnt signalling pathway, as well as Li+ ions protecting chondrocytes and cartilage tissues from the inflammatory osteoarthritis (OA) environment through activation of autophagy. These findings suggest that the incorporation of Li+ ions into bioactive MBG scaffolds is a viable strategy for fabricating bi‐lineage conducive scaffolds that enhance regeneration of osteochondral defects.     

Recent Advances in Design of Functional Biocompatible Hydrogels for Bone Tissue Engineering

Bone related diseases have caused serious threats to human health owing to their complexity and specificity. Fortunately, owing to the unique 3D network structure with high aqueous content and functional properties, emerging hydrogels are regarded as one of the most promising candidates for bone tissue engineering, such as repairing cartilage injury, skull defect, and arthritis. Herein, various design strategies and synthesis methods (e.g., 3D-printing technology and nanoparticle composite strategy) are introduced to prepare implanted hydrogel scaffolds with tunable mechanical strength, favorable biocompatibility, and excellent bioactivity for applying in bone regeneration. Injectable hydrogels based on biocompatible materials (e.g., collagen, hyaluronic acid, chitosan, polyethylene glycol, etc.) possess many advantages in minimally invasive surgery, including adjustable physicochemical properties, filling irregular shapes of defect sites, and on-demand release drugs or growth factors in response to different stimuli (e.g., pH, temperature, redox, enzyme, light, magnetic, etc.). In addition, drug delivery systems based on micro/nanogels are discussed, and its numerous promising designs used in the application of bone diseases (e.g., rheumatoid arthritis, osteoarthritis, cartilage defect) are also briefed in this review. Particularly, several key factors of hydrogel scaffolds (e.g., mechanical property, pore size, and release behavior of active factors) that can induce bone tissue regeneration are also summarized in this review. It is anticipated that advanced approaches and innovative ideas of bioactive hydrogels will be exploited in the clinical field and increase the life quality of patients with the bone injury.     

Biomimetic Elastomeric Bioactive Siloxane‐Based Hybrid Nanofibrous Scaffolds with miRNA Activation: A Joint Physico‐Chemical‐Biological Strategy for Promoting Bone Regeneration

Rapid and efficient disease‐induced or critical‐size bone regeneration remains a challenge in tissue engineering due to the lack of highly bioactive biomaterial scaffolds. Physical structures such as nanostructures, chemical components such as silicon elements, and biological factors such as genes have shown positive effects on bone regeneration. Herein, a bioactive photoluminescent elastomeric silicate‐based nanofibrous scaffold with sustained miRNA release is reported for promoting bone regeneration based on a joint physico‐chemical‐biological strategy. Bioactive nanofibrous scaffolds are fabricated by cospinning poly (ε‐caprolactone) (PCL), elastomeric poly (citrates‐siloxane) (PCS), and bioactive osteogenic miRNA nanocomplexes (denoted PPM nanofibrous scaffolds). The PPM scaffolds possess uniform nanostructures, significantly enhanced tensile stress (≈15 MPa) and modulus (≈32 MPa), improved hydrophilicity (30–60°), controlled biodegradation, and strong blue fluorescence. Bioactive miRNA complexes are efficiently loaded into the nanofibrous matrix and exhibit long‐term release for up to 70 h. The PPM scaffolds significantly promote the adhesion, proliferation, and osteoblast differentiation of bone marrow stem cells in vitro and enhanced rat cranial defect restoration (12 weeks) in vivo. This work reports an attractive joint physico‐chemical‐biological strategy for the design of novel cell/protein‐free bioactive scaffolds for synergistic tissue regeneration.     

Multifunctional Modification of SIS Membrane with Chimeric Peptides to Promote Its Antibacterial,Osteogenic, and Healing-Promoting Abilities for Applying to GBR

Guided bone regeneration (GBR) technology is the most widely used and stable method for bone defect repair. However, infectious bone defect limits the application of this technique. Herein, a small intestinal submucosa (SIS) membrane modified by chimeric peptides as a new type of GBR membrane is developed for efficacious tissue regeneration. Based on the main components of SIS membrane are I and III collagen, collagen binding peptides TKKTLRT and KELNLVY sequences are used to construct chimeric peptides with healing-promoting peptide Hst1 or antibacterial osteogenic peptide JH8194, so as to realize the specifically target of SIS. This method achieves the fast and efficient multifunctional modification of SIS membrane. The chimeric peptides modified SIS (pSIS) membrane has satisfactory biocompatibility and a certain degree of antibacterial activity. Moreover, pSIS promotes the osteogenic related factors expression of rat bone mesenchymal stem cells and demonstrates great bone regeneration in rat skull defect model. Furthermore, pSIS accelerates the migration of oral epithelial cells in vitro and activate integrin α3β1 signal pathway contribute to wound healing. This study presents a novel biomaterial design of GBR membrane, specifically for the treatment of infectious bone defects.     

Microfluidic 3D Printing Responsive Scaffolds with Biomimetic Enrichment Channels for Bone Regeneration

Tissue-engineered scaffolds have been extensively explored for treating bone defects; however, slow and insufficient vascularization throughout the scaffolds remains a key challenge for further application. Herein, a versatile microfluidic 3D printing strategy to fabricate black phosphorus (BP) incorporated fibrous scaffolds with photothermal responsive channels for improving vascularization and bone regeneration is proposed. The thermal channeled scaffolds display reversible shrinkage and swelling behavior controlled by near-infrared irradiation, which facilitates the penetration of suspended cells into the scaffold channels and promotes the prevascularization. Furthermore, the embedded BP nanosheets exhibit intrinsic properties for in situ biomineralization and improve in vitro cell proliferation and osteogenic differentiation. Following transplantation in vivo, these channels also promote host vessel infiltration deep into the scaffolds and effectively accelerate the healing process of bone defects. Thus, it is believed that these near-infrared responsive channeled scaffolds are promising candidates for tissue/vascular ingrowth in diverse tissue engineering applications.     

3D Printed Enzyme-Functionalized Scaffold Facilitates Diabetic Bone Regeneration

Patients with diabetes mellitus (DM) suffer from a high risk of fractures and poor bone healing ability. Surprisingly, no effective therapy is available to treat diabetic bone defect in clinic. Here, a 3D printed enzyme-functionalized scaffold with multiple bioactivities including osteogenesis, angiogenesis, and anti-inflammation in diabetic conditions is proposed. The as-prepared multifunctional scaffold is constituted with alginate, glucose oxidase (GOx), and catalase-assisted biomineralized calcium phosphate nanosheets (CaP@CAT NSs). The GOx inside scaffolds can alleviate the hyperglycemia environment by catalyzing glucose and oxygen into gluconic acid and hydrogen peroxide (H₂O₂). Both the generated H₂O₂ as well as the overproduced H₂O₂ in DM can be scavenged by CaP@CAT NSs, while the initiated hypoxic microenvironment stimulates neovascularization. Moreover, the incorporation of CaP@CAT NSs not only enhance the mechanical property of the scaffolds, but also facilitate bone regeneration by the degraded Ca²⁺ and PO₄³⁻ ions. The remarkable in vitro and in vivo outcomes demonstrate that enzymes functionalized scaffolds can be an effective strategy for enhancing bone tissue regeneration in diabetic conditions, underpinning the potential of multifunctional scaffolds for diabetic bone regeneration.