Composite Scaffolds For Bone Regeneration Research Articles

Preparation and Characterization of Chitosan/Hydroxyapatite Nanowire Composite Scaffolds for Bone Regeneration

Preparation and Characterization of Chitosan/Hydroxyapatite Nanowire Composite Scaffolds for Bone Regeneration

Three-dimensional printed sodium alginate clay nanotube composite scaffold for bone regeneration

Nanoparticles can regulate the rheological behavior of polymers during three-dimensional (3D) printing. To overcome the poor molding performance of pure sodium alginate (SA), the present study introduced clay halloysite nanotubes (HNTs), and a novel SA/HNTs ink with good formability was obtained. Subsequently, a high-performance SA/HNTs composite scaffold for bone defect repair was prepared using 3D printing and high-temperature sintering. The rheological properties, interfacial interactions, and mechanical performance of the SA/HNTs ink demonstrated hydrogen bonds and electrostatic attractions between SA and the HNTs, and the ink exhibited good shape fidelity, printability, and mechanical properties after 3D printing. The SA/HNTs composite hydrogel scaffold can transfer into a rigid ceramic scaffold after high-temperature treatment at 1200 °C. The cell experiments confirmed that the SA/HNTs ceramic scaffold exhibited good biocompatibility and osteogenic activity. In addition, a rat calvarial repair experiment showed that the SA/HNTs scaffolds exhibited good bone repair abilities in vivo. Overall, the SA/HNTs composite scaffolds have excellent formability, biocompatibility, and osteogenic activity and have broad application prospects in the field of bone defect repair.

Functionalized 3D Hydroxyapatite Scaffold by Fusion Peptides-Mediated Small Extracellular Vesicles of Stem Cells for Bone Tissue Regeneration.

3D printing technology offers extensive applications in tissue engineering and regenerative medicine (TERM) because it can create a three-dimensional porous structure with acceptable porosity and fine mechanical qualities that can mimic natural bone. Hydroxyapatite (HA) is commonly used as a bone repair material due to its excellent biocompatibility and osteoconductivity. Small extracellular vesicles (sEVs) derived from bone marrow mesenchymal stem cells (BMSCs) can regulate bone metabolism and stimulate the osteogenic differentiation of stem cells. This study has designed a functionalized bone regeneration scaffold (3D H-P-sEVs) by combining the biological activity of BMSCs-sEVs and the 3D-HA scaffold to improve bone regeneration. The scaffold utilizes the targeting of fusion peptides to increase the loading efficiency of sEVs. The composition, structure, mechanical properties, and in vitro degradation performance of the 3D H-P-sEVs scaffolds were examined. The composite scaffold demonstrated good biocompatibility, substantially increased the expression of osteogenic-related genes and proteins, and had a satisfactory bone integration effect in the critical skull defect model of rats. In conclusion, the combination of EVs and 3D-HA scaffold via fusion peptide provides an innovative composite scaffold for bone regeneration and repair, improving osteogenic performance.

A biomimetic in situ mineralization ECM composite scaffold to promote endogenous bone regeneration

Bone tissue engineering scaffolds constructed from single-component organic materials have inherent limitations. Inspired by the hierarchical structure of physiological natural bone hard tissues, our research explores the construction of organic-inorganic composite scaffold for bone regeneration. In this study, we used a natural and readily obtainable extracellular matrix (ECM) material, i.e., decellularized small intestinal submucosa (SIS), to build the organic component of a phosphorylated hydroxyapatite nanocrystal-containing composite scaffold (nHA@SIS). Guided by polymer-induced liquid-precursor theory, we introduced a soluble inorganic mineralization solution to achieve an inorganic component of nHA@SIS. Using in situ mineralization, we successfully formed inorganic component within SIS and constructed nHA@SIS composite scaffold. We analyzed the physicochemical properties and the osteogenic role of nHA@SIS via a series of in vitro and in vivo studies. Compared with SIS scaffold, the nHA@SIS possessed suitable physicochemical properties, maintained the excellent cell activity of SIS and better guided reorganization of the cell skeleton, thereby achieving superior osteoconductivity and maintaining osteoinductivity at the protein and gene levels. Furthermore, the rat cranial defect area in the nHA@SIS scaffold group was mostly repaired after 12 weeks of implantation, with a larger amount of higher-density new bone tissue being visible at the edge and center than SIS and blank control group. This significantly improved in vivo osteogenic ability indicated the great potential of nHA@SIS for bone tissue engineering applications.

NOVEL HIGH-STRENGTH POLYESTER COMPOSITE SCAFFOLDS FOR BONE REGENERATION.

Repair of critical sized bone defects, particularly in load-bearing areas, is a major clinical problem that requires surgical intervention and implantation of biological or engineered grafts. For load-bearing sites, it is essential to use engineered grafts that have both sufficient mechanical strength and appropriate pore properties to support bone repair and tissue regeneration. Unfortunately, the mechanical properties of such grafts are often compromised due to the creation of pores required to facilitate tissue ingrowth following implantation. To overcome the limitations associated with porous scaffolds and their reduced mechanical strength, we have developed a methodology for creating a solid structure that retains its bulk mechanical properties while also evolving into a porous structure in a biological environment through degradation and erosion. In this study, we utilized polyesters that have been approved by the FDA, including poly (lactic acid) (PLA), poly(glycolic acid) (PGA), their copolymer PLGA (PLGA, with a ratio of 85:15 and 50:50 of PLA:PGA), and poly(caprolactone) (PCL). These polymers and their ceramic composites with tricalcium phosphate (TCP) were compression molded into solid forms, which exhibited mechanical properties with compressive modulus as high as 2745 ± 364 MPa within the range of human trabecular bone and in the lower range of human cortical bone. The use of fast-degrading PLGA (50:50) and PGA as porogens allowed the formation of pores within the solid structures due to their degradation, and the TCP acts as a buffering agent to neutralize their acidic degradation byproducts. These scaffolds facilitated the growth of new blood vessels and tissue ingrowth in a subcutaneous implantation model. In addition, in a rat critical-sized mandibular bone defects these scaffolds supported bone growth with 70% of new bone volume fraction. Furthermore, the extent of bone regeneration was found to be higher for the scaffolds with bone morphogenic proteins (BMP2), indicating their suitability for bone repair and regeneration.

Optimization of a concentrated growth factor/mesoporous bioactive glass composite scaffold and its application in rabbit mandible defect regeneration.

Maxillofacial bone defect repair and regeneration remains a tremendous challenge in the field of stomatology. However, the limited osteoinductivity of artificial materials and the high cost of bioactive agents restrain their clinical translation. This study aimed to construct an economical and efficient concentrated growth factor/mesoporous bioactive glass (CGF/MBG) composite scaffold for bone regeneration. The biochemical composition and biological effects of different forms of CGFs were systematically compared, and the results showed that CGF-conditioned medium effectively promoted proliferation, migration and osteogenesis of allogenic BMSCs. Gel phase CGF (gpCGF) exhibited superior bioactivity and osteoinductivity to liquid phase CGF (lpCGF) and liquid/gel mixed phase CGF (lgpCGF), and was further applied to construct CGF/MBG scaffolds. In vitro studies demonstrated that co-culture with gpCGF-conditioned medium further enhanced the biocompatibility of MBG, increasing cell adhesion and proliferation on the scaffold. On this basis, two compositing approaches to construct the scaffold by fibrin gel formation (CGF/FG/MBG) and freeze-drying (fdCGF/MBG) were applied, and the biological efficacy of CGFs was compared in vivo. In a rabbit mandibular defect model, higher osteogenic efficiency in in situ bone regeneration of CGF/FG/MBG composite scaffolds was proved, compared with fdCGF/MBG. Taken together, the CGF/FG/MBG composite scaffold is expected to be an efficient bone repairing therapy for clinical translation, and the CGF-composited scaffold using gpCGF and the fibrin gel formation method is a promising way to enhance the bioactivity and osteoinductivity of current clinical bone repairing materials, providing new thoughts on the development of future orthopedic biomaterials.

The Use of Newly Synthesized Composite Scaffolds for Bone Regeneration - A Review of Literature

Abstract Bone tissue engineering is a multidisciplinary concept that combines biological and engineering principles to repair bone defects. Three elements that have a fundamental role in bone tissue engineering are scaffolds, stem cells, and bioactive components. Scaffolds mimic extracellular matrix functions and provide mechanical support for the new tissue formation. They are made of different natural and synthetic materials that can be categorized into three main groups: ceramics, metals, and polymers. Among them, synthetic polyesters and their combination with bioceramics, have been the most frequently used for scaffold fabrication. They could be potentially applied in clinical practice in the future as an alternative to the standard use of bone grafts but more studies are needed to assess their performance in the challenging conditions of human bone defects.

Development and Characterization of Functional Polylactic Acid/Chitosan Porous Scaffolds for Bone Tissue Engineering.

In this study, we developed and characterized various open-cell composite scaffolds for bone regeneration. These scaffolds were made from Polylactic acid (PLA) as the scaffold matrix biopolymeric phase, and chitosan (CS) and chitosan-grafted-PLA (CS-g-PLA) copolymer as the dispersed biopolymeric phase. As a first step, successful grafting of PLA onto CS backbone was executed and confirmed by both FTIR and XPS. Mechanical characterization confirmed that adding CS or CS-g-PLA to the intrinsically rigid PLA made their corresponding PLA/CS and PLA/CS-g-PLA composite scaffolds more flexible under compression. This flexibility was higher for the latter due to the improved compatibility between PLA and CS-g-PLA copolymer. The hydrolytic stability of both PLA/CS and PLA/CS-g-PLA composite scaffolds inside phosphate-buffered saline (PBS) solution, as well as MG-63 osteoblast cell adhesion and proliferation inside both scaffolds, were characterized. The corresponding results revealed that PLA/CS composite scaffolds showed hydrolytic degradation due to the cationic properties of CS. However, modified PLA/CS-g-PLA scaffolds were hydrolytically stable due to the improved interfacial adhesion between the PLA matrix and CS-g-PLA copolymer. Finally, biological characterization was done for both PLA/CS and PLA/CS-g-PLA composite scaffolds. Contrarily to what was observed for uncompatibilized PLA/CS scaffolds, compatibilized PLA/CS-g-PLA scaffolds showed a high MG-63 osteoblast cell proliferation after three and five days of cell culture. Moreover, it was observed that cell proliferation increased with CS-g-PLA content. This suggests that the PLA/CS-g-PLA composite scaffolds could be a potential solution for bone regeneration.

3D printed biocompatible graphene oxide, attapulgite, and collagen composite scaffolds for bone regeneration.

Tissue-engineered bone material is one of the effective methods to repair bone defects, but the application is restricted in clinical because of the lack of excellent scaffolds that can induce bone regeneration as well as the difficulty in making scaffolds with personalized structures. 3D printing is an emerging technology that can fabricate bespoke 3D scaffolds with precise structure. However, it is challenging to develop the scaffold materials with excellent printability, osteogenesis ability, and mechanical strength. In this study, graphene oxide (GO), attapulgite (ATP), type I collagen (Col I) and polyvinyl alcohol were used as raw materials to prepare composite scaffolds via 3D bioprinting. The composite materials showed excellent printability. The microcosmic architecture and properties was characterized by scanning electron microscopy, Fourier transform infrared and thermal gravimetric analyzer, respectively. To verify the biocompatibility of the scaffolds, the viability, proliferation and osteogenic differentiation of Bone Marrow Stromal Cells (BMSCs) on the scaffolds were assessed by CCK-8, Live/Dead staining and Real-time PCR in vitro. The composited scaffolds were then implanted into the skull defects on rat for bone regeneration. Hematoxylin-eosin staining, Masson staining and immunohistochemistry staining were carried out in vivo to evaluate the regeneration of bone tissue.The results showed that GO/ATP/COL scaffolds have been demonstrated to possess controlled porosity, water absorption, biodegradability and good apatite-mineralization ability. The scaffold consisting of 0.5% GO/ATP/COL have excellent biocompatibility and was able to promote the growth, proliferation and osteogenic differentiation of mouse BMSCs in vitro. Furthermore, the 0.5% GO/ATP/COL scaffolds were also able to promote bone regeneration of in rat skull defects. Our results illustrated that the 3D printed GO/ATP/COL composite scaffolds have good mechanical properties, excellent cytocompatibility for enhanced mouse BMSCs adhesion, proliferation, and osteogenic differentiation. All these advantages made it potential as a promising biomaterial for osteogenic reconstruction.

Silkworm spinning inspired 3D printing toward a high strength scaffold for bone regeneration.

Inspired by the silkworm spinning process for production of tough cocoons, a gradient printing-assembly technique with silk fibroin (SF) and hydroxyapatite (HA) to achieve high strength scaffolds for bone regeneration is developed. A coaxial extrude-nozzle is employed to provide gathered thickening and shearing for aligned assembly. The aligned SF-HA assembles into the compacted nanostructure, which performs a maximum compressive strength of 166 MPa and bending strength of 40 MPa. Scaffolds with various morphologies could be arbitrarily constructed via extruded 3D printing for the regeneration of cortical bone or cancellous bone. The hemolysis quantification of red blood cells (RBCs), proliferation and flow cytometry of bone marrow stem cells (BMSCs) have proved the excellent biocompatibility of the printed scaffolds. Osteogenic induced differentiation assay in vitro and surgical intervention for rat femoral defect repairing have verified the successful osteogenesis with high mechanical strength and remarkable stability in the physiological environment. The silkworm spinning inspired 3D printing offers a facile approach for the fabrication of implantable scaffolds with high strength and excellent biocompatibility, which is highly desired for the applications of bone tissue engineering.

Electropsun Polycaprolactone Fibres in Bone Tissue Engineering: A Review.

Regeneration of bone tissue requires novel load bearing, biocompatible materials that support adhesion, spreading, proliferation, differentiation, mineralization, ECM production and maturation of bone-forming cells. Polycaprolactone (PCL) has many advantages as a biomaterial for scaffold production including tuneable biodegradation, relatively high mechanical toughness at physiological temperature. Electrospinning produces nanofibrous porous matrices that mimic many properties of natural tissue extracellular matrix with regard to surface area, porosity and fibre alignment. The biocompatibility and hydrophilicity of PCL nanofibres can be improved by combining PCL with other biomaterials to form composite scaffolds for bone regeneration. This work reviews the most recent research on synthesis, characterization and cellular response to nanofibrous PCL scaffolds and the composites of PCL with other natural and synthetic materials for bone tissue engineering.

Biofabrication of 3D printed hydroxyapatite composite scaffolds for bone regeneration

Biofabrication has been adapted in engineering patient-specific biosynthetic grafts for bone regeneration. Herein, we developed a three-dimensional (3D) high-resolution, room-temperature printing approach to fabricate osteoconductive scaffolds using calcium phosphate cement (CPC). The non-aqueous CPC bioinks were composed of tetracalcium phosphate, dicalcium phosphate anhydrous, and Polyvinyl butyral (PVB) dissolved in either ethanol (EtOH) or tetrahydrofuran (THF). They were printed in an aqueous sodium phosphate bath, which performs as a hardening accelerator for hydroxyapatite formation and as a retainer for 3D microstructure. The PVB solvents, EtOH or THF, affected differently the slurry rheological properties, scaffold microstructure, mechanical properties, and osteoconductivity. Our proposed approach overcomes limitations of conventional fabrication methods, which require high-temperature (>50 °C), low-resolution (>400 μm) printing with an inadequate amount of large ceramic particles (>35 μm). This proof-of-concept study opens venues in engineering high-resolution, implantable, and osteoconductive scaffolds with predetermined properties for bone regeneration.

Biomimetic synthesis of Mg-substituted hydroxyapatite nanocomposites and three-dimensional printing of composite scaffolds for bone regeneration.

In this study, we have successfully fabricated magnesium (Mg) substituted hydroxyapatite nanocomposites (Mg-HA) by utilizing type I collagen (COL I) and citric acid (CA) through a bitemplate-induced biomimetic mineralization approach. The obtained composite nanoparticles were subsequently mixed with chitosan (CHI) and gelatin (Gel) to prepare porous scaffolds with interconnected structures by three-dimensional (3D) printing technique. The Mg-HA powders and composite scaffolds were characterized. The results showed that the substitution of Mg for Ca ions reduced the crystallinity of HA crystals, but did not significantly affect the size and structure of the nanocomposites. The morphology of Mg-HA scaffolds turned smoother compared with the HA scaffolds with Mg substitution. Furthermore, the biocompatibility of Mg-HA composite scaffolds was evaluated by metal ion release, cell attachment, proliferation, and differentiation of MC3T3-E1 cells. According to the results, as the more Ca2+ was substituted by Mg2+ , the more Mg2+ was released from the samples and the pH in cultured medium was more acidic. It was suggested that Mg-HA scaffolds presented higher cell attachment, proliferation rate, increased expression of alkaline phosphatase (ALP) activity and osteogenic related gene, including osteocalcin (OCN), runt-related transcription factor 2 (RUNX2), and COL I. Therefore, it was indicated that the 3D printed Mg-HA composite scaffolds with excellent biocompatibility and bioactivity were a potential candidate in bone tissue engineering.

Three-dimensional printing of CaTiO3 incorporated porous β-Ca2SiO4 composite scaffolds for bone regeneration

Three-dimensional (3D) printed bioceramics derived from silicone are of great interest in bone tissue engineering owing to their simple processes and low cost. In this study, calcium titanate (CaTiO3) incorporated porous β-Ca2SiO4 (C2S) composite scaffolds have been successfully fabricated from preceramic resin loaded with CaCO3 and TiO2 fillers by 3D printing. The fabricated scaffolds possessed uniform interconnected macropores (ca. 400μm). The biocompatibility and bioactivity of the CaTiO3-incorporated porous C2S scaffolds were assessed and found that the increase of CaTiO3 significantly decreased the dissolution of the C2S scaffolds, and promoted the cell proliferation and differentiation into osteoblasts. Moreover, CaTiO3-incorporated porous C2S scaffolds possessed a better osteogenic capacity than pure C2S scaffolds in vivo. Therefore, the 3D printed CaTiO3 incorporated porous C2S composite scaffolds would be a promising candidate for bone tissue engineering.

Delivery vehicle of muscle-derived irisin based on silk/calcium silicate/sodium alginate composite scaffold for bone regeneration.

Irisin is a cytokine produced by skeletal muscle and usually plays a pivotal role in inducing fat browning and regulating energy expenditure. In recent years, it was found that irisin might be the molecular entity responsible for muscle-bone connectivity and is useful in osteogenesis induction. To study its effect on bone regeneration, we developed silk/calcium silicate/sodium alginate (SCS) composite scaffold based on an interpenetrating network hydrogel containing silk fibroin, calcium silicate, sodium alginate. Then we loaded irisin on the SCS before coating it with polyvinyl alcohol (PVA). The SCS/P scaffold was physically characterized and some in vitro and in vivo experiments were carried out to evaluate the scaffold effect on bone regeneration. The SCS/P scaffold was showed a porous sponge structure pursuant to scanning electron microscopy analysis. The release kinetics assay demonstrated that irisin was stably released from the irisin-loaded hybrid system (i/SCS/P system) to 50% within 7 days. Moreover, osteoinductive studies using bone marrow stem cells (BMSCs) in vitro exhibited the i/SCS/P system improved the activity of alkaline phosphatase (ALP) and enhanced the expression levels of a series of osteogenic markers containing Runx-2, ALP, BMP2, Osterix, OCN, and OPN. Alizarin red staining also demonstrated the promotion of osteogenesis induced by i/SCS/P scaffolds. In addition, in vivo studies showed that increased bone regeneration with better mineralization and higher quality was found during the repair of rat calvarial defects through utilizing the i/SCS/P system. These data provided strong evidence that the composite i/SCS/P would be a promising substitute for bone tissue engineering.

3D printed PCL/SrHA scaffold for enhanced bone regeneration

Strontium-containing hydroxyapatite (SrHA) is a promising material for bone repair and bone replacement due to the similar inorganic components with natural bone. In this study, the poly(ɛ-caprolactone) (PCL)/SrHA composite scaffold was fabricated by 3D printing method. Scanning electron microscopy (SEM) images of the fabricated scaffolds showed that SrHA was uniformly embedded in the interior of scaffold struts, and in vitro release profiles revealed that Sr and Ca ions released from the PCL/SrHA scaffold in a sustained manner. To confirm the performance of the fabricated composite scaffolds for bone regeneration, the cell proliferation and osteogenic differentiation of rat bone marrow-derived mesenchymal stem cells (BMSCs) grown on the scaffolds were evaluated. The experimental results indicated that incorporation of SrHA in the 3D printed PCL scaffold significantly facilitated the cell proliferation, and the PCL/SrHA scaffolds induced higher levels of BMSCs differentiation compared to the PCL and PCL/HA scaffolds, as demonstrated by ALP activity and osteo-related gene expression. Furthermore, in vivo cranial defect experiments further revealed that the incorporation of SrHA into 3D printed PCL scaffold was capable of promoting bone regeneration. Taken together, these results indicate that the PCL/SrHA composite scaffold can be readily fabricated by 3D printing technology and is highly promising as implantable material for bone tissue engineering application.

Characterization of a Porous BMP-6-Loaded Composite Scaffold for Bone Regeneration in Rat Calvarial Bone Defects

Characterization of a Porous BMP-6-Loaded Composite Scaffold for Bone Regeneration in Rat Calvarial Bone Defects

Incorporation of Stromal Cell-Derived Factor-1α in Three-Dimensional Hydroxyapatite/Polyacrylonitrile Composite Scaffolds for Bone Regeneration.

Bone regeneration strategies rely on biomaterial constructs with stem cells or growth factors. By comparison, cell homing strategies employ chemokines to recruit the host endogenous stem or progenitor cells to the defect site to support endogenous healing. In the present study, we used a novel fluffy hydroxyapatite/polyacrylonitrile (HA/PAN) composite scaffold to provide a better three-dimensional cell culture microenvironment. These HA/PAN composite scaffolds loaded with stromal cell-derived factor-1α (SDF-1α) provided a diffusion-controlled SDF-1α release profile and endowed the scaffolds with cell homing capabilities. Furthermore, the scaffolds significantly stimulated bone marrow stromal cell (BMSC) recruitment, facilitated BMSC osteogenic differentiation, and promoted ectopic bone formation. Our results suggest that a HA/PAN composite scaffold loaded with SDF-1α offers a clinically beneficial bone repair strategy.

Osteoconductive 3D porous composite scaffold from regenerated cellulose and cuttlebone-derived hydroxyapatite.

Recently, usage of marine-derived materials in biomedical field has come into prominence due to their promising characteristics such as biocompatibility, low immunogenicity and wide accessibility. Among these marine sources, cuttlebone has been used as a valuable component with its trace elemental composition in traditional medicine. Recent studies have focused on the use of cuttlebone as a bioactive agent for tissue engineering applications. In this study, hydroxyapatite particles were obtained by hydrothermal synthesis of cuttlebone and incorporated to cellulose scaffolds to fabricate an osteoconductive composite scaffold for bone regeneration. Elemental analysis of raw cuttlebone material from different coastal zones and cuttlebone-derived HAp showed that various macro-, micro- and trace elements - Ca, P, Na, Mg, Cu, Sr, Cl, K, S, Br, Fe and Zn were found in a very similar amount. Moreover, biologically unfavorable heavy metals, such as Ag, Cd, Pb or V, were not detected in any cuttlebone specimen. Carbonated hydroxyapatite particle was further synthesized from cuttlebone microparticles via hydrothermal treatment and used as a mineral filler for the preparation of cellulose-based composite scaffolds. Interconnected highly porous structure of the scaffolds was confirmed by micro-computed tomography. The mean pore size of the scaffolds was 510 µm with a porosity of 85%. The scaffolds were mechanically characterized with a compression test and cuttlebone-derived HAp incorporation enhanced the mechanical properties of cellulose scaffolds. In vitro cell culture studies indicated that MG-63 cells proliferated well on scaffolds. In addition, cuttlebone-derived hydroxyapatite significantly induced the ALP activity and osteocalcin secretion. Besides, HAp incorporation increased the surface mineralization which is the major step for bone tissue regeneration.

Magnetic bioinspired micro/nanostructured composite scaffold for bone regeneration.

Magnetic-responsive materials are promising for applications in various biomedical fields. Especially, superparamagnetic nanoparticles are widely used in magnetic system for bone tissue engineering owing to superior biocompatibility and long term stability. Based on the idea of in situ bionics, we successfully incorporate the nano-hydroxyapatite (nHAP) and Fe3O4 nanoparticles which were prepared by in situ crystallization and freeze-drying technique into the chitosan/collagen (CS/Col) organic matrix to achieve the uniform dispersion of inorganic substrate with nanometer-scale. The in vitro results of the physicochemical and biocompatibility tests showed that CS/Col/Fe3O4/nHAP magnetic scaffold possessed superior structural and mechanical performance for cell adhesion and proliferation, as well as the osteogenic differentiation. Mineralization experiments showed better bioactive and good ability of in situ biomimetic mineralization. Moreover, from the in vivo model of SD rats' skull defects proved that the CS/Col/Fe3O4/nHAP hybrid scaffold had a better tissue compatibility and higher bone regeneration ability when implanted into the skull defects comparing to control group. Herein, the magnetic hybrid micro/nanostructured scaffold showed a potential application for bone defect repair.